Merge pull request #25272 from vespa-engine/vekterli/yuletide-cleanup

Yuletide distributor code cleanup

109 files changed, 515 insertions, 724 deletions

diff --git a/document/src/vespa/document/bucket/bucketid.h b/document/src/vespa/document/bucket/bucketid.h
index 370948c1acc..e83418fb07e 100644
--- a/document/src/vespa/document/bucket/bucketid.h
+++ b/document/src/vespa/document/bucket/bucketid.h
@@ -49,7 +49,7 @@ public:
     /** Create an initially unset bucket id. */
     constexpr BucketId() noexcept : _id(0) {}
     /** Create a bucket id with the given raw unchecked content. */
-    explicit BucketId(Type id) noexcept : _id(id) {}
+    constexpr explicit BucketId(Type id) noexcept : _id(id) {}
     /** Create a bucket id using a set of bits from a raw unchecked value. */
     BucketId(uint32_t useBits, Type id) noexcept : _id(createUsedBits(useBits, id)) { }
 
diff --git a/storage/src/tests/distributor/bucketgctimecalculatortest.cpp b/storage/src/tests/distributor/bucketgctimecalculatortest.cpp
index 33cd7bd637a..aaa228758b0 100644
--- a/storage/src/tests/distributor/bucketgctimecalculatortest.cpp
+++ b/storage/src/tests/distributor/bucketgctimecalculatortest.cpp
@@ -12,7 +12,7 @@ struct MockBucketIdHasher : public BucketGcTimeCalculator::BucketIdHasher
 {
     size_t nextGeneratedHash {0};
 
-    size_t doHash(const document::BucketId&) const override {
+    size_t doHash(const document::BucketId&) const noexcept override {
         return nextGeneratedHash;
     }
 };
diff --git a/storage/src/tests/distributor/maintenancemocks.h b/storage/src/tests/distributor/maintenancemocks.h
index 2809a81f79b..5bcd8f962a6 100644
--- a/storage/src/tests/distributor/maintenancemocks.h
+++ b/storage/src/tests/distributor/maintenancemocks.h
@@ -50,7 +50,7 @@ public:
     }
 
     void onClose(DistributorStripeMessageSender&) override {}
-    const char* getName() const override { return "MockOperation"; }
+    const char* getName() const noexcept override { return "MockOperation"; }
     const std::string& getDetailedReason() const override {
         return _reason;
     }
diff --git a/storage/src/vespa/storage/bucketdb/bucketmanager.cpp b/storage/src/vespa/storage/bucketdb/bucketmanager.cpp
index 9b3ad5c8e22..64c66401992 100644
--- a/storage/src/vespa/storage/bucketdb/bucketmanager.cpp
+++ b/storage/src/vespa/storage/bucketdb/bucketmanager.cpp
@@ -97,11 +97,12 @@ namespace {
     template<bool log>
     class DistributorInfoGatherer
     {
-        typedef api::RequestBucketInfoReply::EntryVector ResultArray;
-        DistributorStateCache _state;
+        using ResultArray = api::RequestBucketInfoReply::EntryVector;
+
+        DistributorStateCache                      _state;
         std::unordered_map<uint16_t, ResultArray>& _result;
-        const document::BucketIdFactory& _factory;
-        std::shared_ptr<const lib::Distribution> _storageDistribution;
+        const document::BucketIdFactory&           _factory;
+        std::shared_ptr<const lib::Distribution>  _storageDistribution;
 
     public:
         DistributorInfoGatherer(
@@ -123,9 +124,7 @@ namespace {
             try{
                 uint16_t i = _state.getOwner(b);
                 auto it = _result.find(i);
-                    // Template parameter. This block should not be included
-                    // in version not logging.
-                if (log) {
+                if constexpr (log) {
                     LOG(spam, "Bucket %s (reverse %" PRIu64 "), should be handled"
                               " by distributor %u which we are %sgenerating "
                               "state for.",
@@ -164,13 +163,13 @@ namespace {
             uint64_t active;
             uint64_t ready;
 
-            Count() noexcept : docs(0), bytes(0), buckets(0), active(0), ready(0) {}
+            constexpr Count() noexcept : docs(0), bytes(0), buckets(0), active(0), ready(0) {}
         };
 
         Count    count;
         uint32_t lowestUsedBit;
 
-        MetricsUpdater() noexcept
+        constexpr MetricsUpdater() noexcept
             : count(), lowestUsedBit(58) {}
 
         void operator()(document::BucketId::Type bucketId,
diff --git a/storage/src/vespa/storage/common/CMakeLists.txt b/storage/src/vespa/storage/common/CMakeLists.txt
index 33efbb571fd..4a712719d53 100644
--- a/storage/src/vespa/storage/common/CMakeLists.txt
+++ b/storage/src/vespa/storage/common/CMakeLists.txt
@@ -8,6 +8,7 @@ vespa_add_library(storage_common OBJECT
     distributorcomponent.cpp
     global_bucket_space_distribution_converter.cpp
     messagebucket.cpp
+    message_guard.cpp
     messagesender.cpp
     node_identity.cpp
     reindexing_constants.cpp
diff --git a/storage/src/vespa/storage/common/bucket_resolver.h b/storage/src/vespa/storage/common/bucket_resolver.h
index 0b8e8b18430..ea261200b7b 100644
--- a/storage/src/vespa/storage/common/bucket_resolver.h
+++ b/storage/src/vespa/storage/common/bucket_resolver.h
@@ -12,7 +12,7 @@ namespace storage {
  * Interface for resolving which bucket a given a document id belongs to.
  */
 struct BucketResolver {
-    virtual ~BucketResolver() {}
+    virtual ~BucketResolver() = default;
     virtual document::Bucket bucketFromId(const document::DocumentId &documentId) const = 0;
     virtual document::BucketSpace bucketSpaceFromName(const vespalib::string &bucketSpace) const = 0;
     virtual vespalib::string nameFromBucketSpace(const document::BucketSpace &bucketSpace) const = 0;
diff --git a/storage/src/vespa/storage/common/bucketmessages.h b/storage/src/vespa/storage/common/bucketmessages.h
index ca3b28188ec..ccee12938b2 100644
--- a/storage/src/vespa/storage/common/bucketmessages.h
+++ b/storage/src/vespa/storage/common/bucketmessages.h
@@ -17,8 +17,8 @@ class ReadBucketList : public api::InternalCommand {
     document::BucketSpace _bucketSpace;
 
 public:
-    typedef std::unique_ptr<ReadBucketList> UP;
-    static const uint32_t ID = 2003;
+    using UP = std::unique_ptr<ReadBucketList>;
+    static constexpr uint32_t ID = 2003;
 
     ReadBucketList(document::BucketSpace bucketSpace);
     ~ReadBucketList();
@@ -40,9 +40,9 @@ class ReadBucketListReply : public api::InternalReply {
     spi::BucketIdListResult::List _buckets;
 
 public:
-    typedef std::unique_ptr<ReadBucketListReply> UP;
-    typedef std::shared_ptr<ReadBucketListReply> SP;
-    static const uint32_t ID = 2004;
+    using UP = std::unique_ptr<ReadBucketListReply>;
+    using SP = std::shared_ptr<ReadBucketListReply>;
+    static constexpr uint32_t ID = 2004;
 
     ReadBucketListReply(const ReadBucketList& cmd);
     ~ReadBucketListReply();
@@ -72,7 +72,7 @@ class ReadBucketInfo : public api::InternalCommand {
     document::Bucket _bucket;
 
 public:
-    static const uint32_t ID = 2005;
+    static constexpr uint32_t ID = 2005;
 
     ReadBucketInfo(const document::Bucket &bucket);
     ~ReadBucketInfo();
@@ -95,7 +95,7 @@ class ReadBucketInfoReply : public api::InternalReply {
     document::Bucket _bucket;
 
 public:
-    static const uint32_t ID = 2006;
+    static constexpr uint32_t ID = 2006;
 
     ReadBucketInfoReply(const ReadBucketInfo& cmd);
     ~ReadBucketInfoReply();
diff --git a/storage/src/vespa/storage/common/doneinitializehandler.h b/storage/src/vespa/storage/common/doneinitializehandler.h
index 41566f493b1..9aaa4e04dc7 100644
--- a/storage/src/vespa/storage/common/doneinitializehandler.h
+++ b/storage/src/vespa/storage/common/doneinitializehandler.h
@@ -13,7 +13,7 @@
 namespace storage {
 
 struct DoneInitializeHandler {
-    virtual ~DoneInitializeHandler() {}
+    virtual ~DoneInitializeHandler() = default;
     virtual void notifyDoneInitializing() = 0;
 };
 
diff --git a/storage/src/vespa/storage/common/hostreporter/CMakeLists.txt b/storage/src/vespa/storage/common/hostreporter/CMakeLists.txt
index 04006b3994b..60919a80bab 100644
--- a/storage/src/vespa/storage/common/hostreporter/CMakeLists.txt
+++ b/storage/src/vespa/storage/common/hostreporter/CMakeLists.txt
@@ -2,7 +2,6 @@
 vespa_add_library(storage_hostreporter OBJECT
     SOURCES
     hostinfo.cpp
-    kernelmetrictool.cpp
     versionreporter.cpp
     DEPENDS
 )
diff --git a/storage/src/vespa/storage/common/hostreporter/kernelmetrictool.cpp b/storage/src/vespa/storage/common/hostreporter/kernelmetrictool.cpp
deleted file mode 100644
index d831a404654..00000000000
--- a/storage/src/vespa/storage/common/hostreporter/kernelmetrictool.cpp
+++ /dev/null
@@ -1,76 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#include "kernelmetrictool.h"
-#include <vespa/vespalib/io/fileutil.h>
-#include <vespa/vespalib/text/stringtokenizer.h>
-#include <vespa/vespalib/stllike/asciistream.h>
-#include <vespa/vespalib/util/exceptions.h>
-#include <cctype>
-
-namespace storage {
-namespace kernelmetrictool {
-
-
-vespalib::string readFile(const char* fileName) {
-    return vespalib::asciistream::createFromDevice(fileName).str();
-}
-
-vespalib::string stripWhitespace(const vespalib::string& s) {
-    vespalib::string::size_type start(0);
-    vespalib::string::size_type stop(s.size() - 1);
-    while (true) {
-        if (start == s.size()) return vespalib::string("");
-        if (!std::isspace(s[start])) break;
-        ++start;
-    }
-    while (true) {
-        if (!std::isspace(s[stop])) break;
-        --stop;
-    }
-    return s.substr(start, stop - start + 1);
-}
-
-vespalib::string getLine(vespalib::stringref key,
-                         vespalib::stringref content)
-{
-    vespalib::string::size_type start(0);
-    vespalib::string::size_type stop(content.find('\n'));
-    while (true) {
-        bool last = (stop == vespalib::string::npos);
-        vespalib::stringref line(content.substr(start, stop - start));
-        for (uint32_t i=0, n=line.size(); i<n; ++i) {
-            if (std::isspace(line[i])) {
-                vespalib::stringref s(line.substr(0, i));
-                if (s == key) return line;
-            }
-        }
-        if (last) break;
-        start = stop + 1;
-        stop = content.find('\n', start);
-    }
-    return "";
-}
-
-vespalib::string getToken(uint32_t index, const vespalib::string& line) {
-    vespalib::StringTokenizer st(line, " \t\n", "");
-    st.removeEmptyTokens();
-    return (index >= st.size() ? "" : st[index]);
-}
-
-uint32_t getTokenCount(const vespalib::string& line) {
-    vespalib::StringTokenizer st(line, " \t\n", "");
-    st.removeEmptyTokens();
-    return st.size();
-}
-
-uint64_t toLong(vespalib::stringref s, int base) {
-    char* endptr;
-    // FIXME C++17 range-safe from_chars() instead of strtoull()
-    uint64_t result(strtoull(s.data(), &endptr, base));
-    if ((s.data() + s.size()) != endptr) {
-        throw vespalib::IllegalArgumentException("Parsing '" + s + "' as a long.");
-    }
-    return result;
-}
-}
-} /* namespace storage */
diff --git a/storage/src/vespa/storage/common/hostreporter/kernelmetrictool.h b/storage/src/vespa/storage/common/hostreporter/kernelmetrictool.h
deleted file mode 100644
index df961c882e1..00000000000
--- a/storage/src/vespa/storage/common/hostreporter/kernelmetrictool.h
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-/*
- * This file contains various tools for use by reporters when fetching os information.
- */
-
-#ifndef STORAGE_SRC_CPP_STORAGE_COMMON_HOSTREPORTER_KERNELMETRICTOOL_H_
-#define STORAGE_SRC_CPP_STORAGE_COMMON_HOSTREPORTER_KERNELMETRICTOOL_H_
-
-#include <vespa/vespalib/stllike/string.h>
-
-namespace storage {
-namespace kernelmetrictool {
-
-vespalib::string readFile(const char* fileName);
-
-vespalib::string stripWhitespace(const vespalib::string& s);
-
-vespalib::string getLine(vespalib::stringref key,
-                         vespalib::stringref content);
-
-vespalib::string getToken(uint32_t index, const vespalib::string& line);
-
-uint32_t getTokenCount(const vespalib::string& line);
-
-uint64_t toLong(vespalib::stringref s, int base = 0) ;
-
-} /* namespace kernelmetrictool */
-} /* namespace storage */
-
-#endif /* STORAGE_SRC_CPP_STORAGE_COMMON_HOSTREPORTER_KERNELMETRICTOOL_H_ */
diff --git a/storage/src/vespa/storage/common/message_guard.cpp b/storage/src/vespa/storage/common/message_guard.cpp
new file mode 100644
index 00000000000..335b2c3d4d7
--- /dev/null
+++ b/storage/src/vespa/storage/common/message_guard.cpp
@@ -0,0 +1,16 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+#include "message_guard.h"
+
+namespace storage {
+
+MessageGuard::~MessageGuard() {
+    _lock.unlock();
+    for (uint32_t i = 0; i < messagesUp.size(); i++) {
+        _messageSender.sendUp(messagesUp[i]);
+    }
+    for (uint32_t i = 0; i < messagesDown.size(); i++) {
+        _messageSender.sendDown(messagesDown[i]);
+    }
+}
+
+}
diff --git a/storage/src/vespa/storage/common/message_guard.h b/storage/src/vespa/storage/common/message_guard.h
new file mode 100644
index 00000000000..682d7a3dc99
--- /dev/null
+++ b/storage/src/vespa/storage/common/message_guard.h
@@ -0,0 +1,39 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+#pragma once
+
+#include "messagesender.h"
+#include <memory>
+#include <mutex>
+#include <vector>
+
+namespace storage {
+
+class MessageGuard {
+    std::vector<std::shared_ptr<api::StorageMessage>> messagesUp;
+    std::vector<std::shared_ptr<api::StorageMessage>> messagesDown;
+
+    std::unique_lock<std::mutex> _lock;
+    ChainedMessageSender& _messageSender;
+
+public:
+    MessageGuard(std::mutex& lock, ChainedMessageSender& messageSender)
+        : _lock(lock),
+          _messageSender(messageSender)
+    {}
+    ~MessageGuard();
+
+    void send(const std::shared_ptr<api::StorageMessage>& message) {
+        sendUp(message);
+    }
+
+    void sendUp(const std::shared_ptr<api::StorageMessage>& message) {
+        messagesUp.push_back(message);
+    }
+
+    void sendDown(const std::shared_ptr<api::StorageMessage>& message) {
+        messagesDown.push_back(message);
+    }
+};
+
+}
+
diff --git a/storage/src/vespa/storage/common/messagebucket.h b/storage/src/vespa/storage/common/messagebucket.h
index b84c36bf08c..c8805cad1b3 100644
--- a/storage/src/vespa/storage/common/messagebucket.h
+++ b/storage/src/vespa/storage/common/messagebucket.h
@@ -14,8 +14,7 @@ class StorageMessage;
  * @throws vespalib::IllegalArgumentException if msg does not
  *     have a bucket id.
  */
-document::Bucket getStorageMessageBucket(
-        const api::StorageMessage& msg);
+document::Bucket getStorageMessageBucket(const api::StorageMessage& msg);
 
 }
 
diff --git a/storage/src/vespa/storage/common/nodestateupdater.h b/storage/src/vespa/storage/common/nodestateupdater.h
index 8d378e1ecd5..842828a1b89 100644
--- a/storage/src/vespa/storage/common/nodestateupdater.h
+++ b/storage/src/vespa/storage/common/nodestateupdater.h
@@ -36,7 +36,7 @@ struct StateListener {
 };
 
 struct NodeStateUpdater {
-    typedef std::unique_ptr<NodeStateUpdater> UP;
+    using UP = std::unique_ptr<NodeStateUpdater>;
 
     virtual ~NodeStateUpdater() = default;
 
@@ -53,8 +53,8 @@ struct NodeStateUpdater {
      * before altering the state.
      */
     struct Lock {
-        typedef std::shared_ptr<Lock> SP;
-        virtual ~Lock() {}
+        using SP = std::shared_ptr<Lock>;
+        virtual ~Lock() = default;
     };
     virtual Lock::SP grabStateChangeLock() = 0;
 
diff --git a/storage/src/vespa/storage/common/servicelayercomponent.h b/storage/src/vespa/storage/common/servicelayercomponent.h
index 3eaec863aa5..2ab8d6a8dfb 100644
--- a/storage/src/vespa/storage/common/servicelayercomponent.h
+++ b/storage/src/vespa/storage/common/servicelayercomponent.h
@@ -59,7 +59,7 @@ class ServiceLayerComponent : public StorageComponent,
         _minUsedBitsTracker = &tracker;
     }
 public:
-    typedef std::unique_ptr<ServiceLayerComponent> UP;
+    using UP = std::unique_ptr<ServiceLayerComponent>;
 
     ServiceLayerComponent(ServiceLayerComponentRegister& compReg,
                           vespalib::stringref name)
diff --git a/storage/src/vespa/storage/common/statusmessages.h b/storage/src/vespa/storage/common/statusmessages.h
index 336df137e41..12432bfe095 100644
--- a/storage/src/vespa/storage/common/statusmessages.h
+++ b/storage/src/vespa/storage/common/statusmessages.h
@@ -23,7 +23,7 @@ class RequestStatusPage : public api::InternalCommand {
                             // in which results should be sorted on status page.
                             // (Used by filestor threads)
 public:
-    static const uint32_t ID = 2100;
+    static constexpr uint32_t ID = 2100;
 
     RequestStatusPage(const framework::HttpUrlPath& path);
     ~RequestStatusPage();
@@ -46,7 +46,7 @@ class RequestStatusPageReply : public api::InternalReply {
     std::string _status;
     std::string _sortToken;
 public:
-    static const uint32_t ID = 2101;
+    static constexpr uint32_t ID = 2101;
 
     RequestStatusPageReply(const RequestStatusPage& cmd, const std::string& status);
     ~RequestStatusPageReply();
diff --git a/storage/src/vespa/storage/common/storagelink.h b/storage/src/vespa/storage/common/storagelink.h
index 2111dbadbc4..4961bd96741 100644
--- a/storage/src/vespa/storage/common/storagelink.h
+++ b/storage/src/vespa/storage/common/storagelink.h
@@ -37,7 +37,7 @@ class StorageLink : public document::Printable,
                     protected api::MessageHandler
 {
 public:
-    typedef std::unique_ptr<StorageLink> UP;
+    using UP = std::unique_ptr<StorageLink>;
 
     enum State { CREATED, OPENED, CLOSING, FLUSHINGDOWN, FLUSHINGUP, CLOSED };
 
diff --git a/storage/src/vespa/storage/common/vectorprinter.h b/storage/src/vespa/storage/common/vectorprinter.h
deleted file mode 100644
index 62daba9bd70..00000000000
--- a/storage/src/vespa/storage/common/vectorprinter.h
+++ /dev/null
@@ -1,48 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#pragma once
-
-#include <vector>
-#include <ostream>
-
-namespace storage {
-
-template <typename T>
-class VectorPrinter
-{
-public:
-    VectorPrinter(const std::vector<T>& vec,
-                  const char* separator)
-        : _vec(&vec),
-          _separator(separator)
-    {}
-
-    void print(std::ostream& os) const {
-        for (uint32_t i = 0; i < _vec->size(); ++i) {
-            if (i != 0) {
-                os << _separator;
-            }
-            os << (*_vec)[i];
-        }
-    }
-private:
-    const std::vector<T>* _vec;
-    const char* _separator;
-};
-
-template <typename T>
-inline std::ostream&
-operator<<(std::ostream& os, const VectorPrinter<T>& printer)
-{
-    printer.print(os);
-    return os;
-}
-
-template <typename T>
-inline VectorPrinter<T>
-commaSeparated(const std::vector<T>& vec)
-{
-    return VectorPrinter<T>(vec, ",");
-}
-
-}
-
diff --git a/storage/src/vespa/storage/common/visitorfactory.h b/storage/src/vespa/storage/common/visitorfactory.h
index 48b9dd6d15f..a60ffadbdb0 100644
--- a/storage/src/vespa/storage/common/visitorfactory.h
+++ b/storage/src/vespa/storage/common/visitorfactory.h
@@ -16,17 +16,17 @@ class Visitor;
 
 class VisitorEnvironment {
 public:
-    typedef std::unique_ptr<VisitorEnvironment> UP;
-    VisitorEnvironment() {}
-    virtual ~VisitorEnvironment() {}
+    using UP = std::unique_ptr<VisitorEnvironment>;
+    VisitorEnvironment() = default;
+    virtual ~VisitorEnvironment() = default;
 };
 
 class VisitorFactory {
 public:
-    typedef std::shared_ptr<VisitorFactory> SP;
-    typedef std::map<std::string, std::shared_ptr<VisitorFactory> > Map;
+    using SP = std::shared_ptr<VisitorFactory>;
+    using Map = std::map<std::string, std::shared_ptr<VisitorFactory>>;
 
-    virtual ~VisitorFactory() {};
+    virtual ~VisitorFactory() = default;
 
     virtual VisitorEnvironment::UP makeVisitorEnvironment(StorageComponent&) = 0;
 
diff --git a/storage/src/vespa/storage/distributor/activecopy.cpp b/storage/src/vespa/storage/distributor/activecopy.cpp
index 71fcc77bd0b..a4ee4a51135 100644
--- a/storage/src/vespa/storage/distributor/activecopy.cpp
+++ b/storage/src/vespa/storage/distributor/activecopy.cpp
@@ -15,7 +15,9 @@ namespace std {
         for (uint32_t i=0; i<v.size(); ++i) {
             out << "\n  " << v[i];
         }
-        if (!v.empty()) out << "\n";
+        if (!v.empty()) {
+            out << "\n";
+        }
         return out << "]";
     }
 }
@@ -113,7 +115,9 @@ namespace {
         result.reserve(e->getNodeCount());
         for (uint32_t i=0, n=e->getNodeCount(); i < n; ++i) {
             const BucketCopy& cp = e->getNodeRef(i);
-            if (!cp.valid()) continue;
+            if (!cp.valid()) {
+                continue;
+            }
             result.push_back(cp.getNode());
         }
         return result;
@@ -185,9 +189,13 @@ ActiveList::print(std::ostream& out, bool verbose,
             out << "\n" << indent << "  "
                 << _v[i]._nodeIndex << " " << _v[i].getReason();
         }
-        if (!_v.empty()) out << "\n" << indent;
+        if (!_v.empty()) {
+            out << "\n" << indent;
+        }
     } else {
-        if (!_v.empty()) out << _v[0]._nodeIndex;
+        if (!_v.empty()) {
+            out << _v[0]._nodeIndex;
+        }
         for (size_t i=1; i<_v.size(); ++i) {
             out << " " << _v[i]._nodeIndex;
         }
@@ -196,10 +204,12 @@ ActiveList::print(std::ostream& out, bool verbose,
 }
 
 bool
-ActiveList::contains(uint16_t node) const
+ActiveList::contains(uint16_t node) const noexcept
 {
-    for (const auto & candadate : _v) {
-        if (node == candadate._nodeIndex) return true;
+    for (const auto& candidate : _v) {
+        if (node == candidate._nodeIndex) {
+            return true;
+        }
     }
     return false;
 }
diff --git a/storage/src/vespa/storage/distributor/activecopy.h b/storage/src/vespa/storage/distributor/activecopy.h
index ee679519a19..258fe3cdf16 100644
--- a/storage/src/vespa/storage/distributor/activecopy.h
+++ b/storage/src/vespa/storage/distributor/activecopy.h
@@ -10,7 +10,7 @@ namespace storage::distributor {
 class ActiveList;
 
 struct ActiveCopy {
-    ActiveCopy() : _nodeIndex(-1), _ideal(-1), _doc_count(0), _ready(false), _active(false) { }
+    constexpr ActiveCopy() noexcept : _nodeIndex(-1), _ideal(-1), _doc_count(0), _ready(false), _active(false) { }
     ActiveCopy(uint16_t node, const BucketDatabase::Entry& e, const std::vector<uint16_t>& idealState);
 
     vespalib::string getReason() const;
@@ -35,11 +35,11 @@ public:
     ActiveList() {}
     ActiveList(std::vector<ActiveCopy>&& v) : _v(std::move(v)) { }
 
-    ActiveCopy& operator[](size_t i) { return _v[i]; }
-    const ActiveCopy& operator[](size_t i) const { return _v[i]; }
-    bool contains(uint16_t) const;
-    bool empty() const { return _v.empty(); }
-    size_t size() const { return _v.size(); }
+    ActiveCopy& operator[](size_t i) noexcept { return _v[i]; }
+    const ActiveCopy& operator[](size_t i) const noexcept { return _v[i]; }
+    [[nodiscard]] bool contains(uint16_t) const noexcept;
+    [[nodiscard]] bool empty() const noexcept { return _v.empty(); }
+    size_t size() const noexcept { return _v.size(); }
     void print(std::ostream&, bool verbose, const std::string& indent) const override;
 };
 
diff --git a/storage/src/vespa/storage/distributor/bucket_ownership_flags.h b/storage/src/vespa/storage/distributor/bucket_ownership_flags.h
index a72aa33265e..e40af18d9df 100644
--- a/storage/src/vespa/storage/distributor/bucket_ownership_flags.h
+++ b/storage/src/vespa/storage/distributor/bucket_ownership_flags.h
@@ -17,14 +17,14 @@ class BucketOwnershipFlags {
     static constexpr uint8_t owned_in_pending_state_flag = 0x2;
     
 public:
-    BucketOwnershipFlags() noexcept
+    constexpr BucketOwnershipFlags() noexcept
         : _flags(0)
     { }
 
-    bool owned_in_current_state() const noexcept { return ((_flags & owned_in_current_state_flag) != 0); }
-    bool owned_in_pending_state() const noexcept {  return ((_flags & owned_in_pending_state_flag) != 0); }
-    void set_owned_in_current_state() noexcept { _flags |= owned_in_current_state_flag; }
-    void set_owned_in_pending_state() noexcept { _flags |= owned_in_pending_state_flag; }
+    constexpr bool owned_in_current_state() const noexcept { return ((_flags & owned_in_current_state_flag) != 0); }
+    constexpr bool owned_in_pending_state() const noexcept {  return ((_flags & owned_in_pending_state_flag) != 0); }
+    constexpr void set_owned_in_current_state() noexcept { _flags |= owned_in_current_state_flag; }
+    constexpr void set_owned_in_pending_state() noexcept { _flags |= owned_in_pending_state_flag; }
 };
 
 }
diff --git a/storage/src/vespa/storage/distributor/bucket_spaces_stats_provider.h b/storage/src/vespa/storage/distributor/bucket_spaces_stats_provider.h
index eee56d92576..18dc3c93cd8 100644
--- a/storage/src/vespa/storage/distributor/bucket_spaces_stats_provider.h
+++ b/storage/src/vespa/storage/distributor/bucket_spaces_stats_provider.h
@@ -17,30 +17,30 @@ private:
     size_t _bucketsTotal;
     size_t _bucketsPending;
 public:
-    BucketSpaceStats(size_t bucketsTotal_, size_t bucketsPending_)
+    constexpr BucketSpaceStats(size_t bucketsTotal_, size_t bucketsPending_) noexcept
         : _valid(true),
           _bucketsTotal(bucketsTotal_),
           _bucketsPending(bucketsPending_)
     {}
-    BucketSpaceStats()
+    constexpr BucketSpaceStats() noexcept
         : _valid(false),
           _bucketsTotal(0),
           _bucketsPending(0)
     {}
 
-    static BucketSpaceStats make_invalid() noexcept { return {}; }
+    static constexpr BucketSpaceStats make_invalid() noexcept { return {}; }
 
-    bool valid() const noexcept { return _valid; }
+    [[nodiscard]] bool valid() const noexcept { return _valid; }
     size_t bucketsTotal() const noexcept { return _bucketsTotal; }
     size_t bucketsPending() const noexcept { return _bucketsPending; }
 
-    bool operator==(const BucketSpaceStats& rhs) const {
+    bool operator==(const BucketSpaceStats& rhs) const noexcept {
         return (_valid == rhs._valid) &&
                 (_bucketsTotal == rhs._bucketsTotal) &&
                 (_bucketsPending == rhs._bucketsPending);
     }
 
-    void merge(const BucketSpaceStats& rhs) {
+    void merge(const BucketSpaceStats& rhs) noexcept {
         _valid = _valid && rhs._valid;
         _bucketsTotal += rhs._bucketsTotal;
         _bucketsPending += rhs._bucketsPending;
diff --git a/storage/src/vespa/storage/distributor/bucketgctimecalculator.h b/storage/src/vespa/storage/distributor/bucketgctimecalculator.h
index 201173c661a..f8d30b6e526 100644
--- a/storage/src/vespa/storage/distributor/bucketgctimecalculator.h
+++ b/storage/src/vespa/storage/distributor/bucketgctimecalculator.h
@@ -22,14 +22,14 @@ class BucketGcTimeCalculator
 {
 public:
     class BucketIdHasher {
-        virtual size_t doHash(const document::BucketId&) const = 0;
+        virtual size_t doHash(const document::BucketId&) const noexcept = 0;
     public:
-        virtual ~BucketIdHasher() {}
-        size_t hash(const document::BucketId& b) const { return doHash(b); }
+        virtual ~BucketIdHasher() = default;
+        size_t hash(const document::BucketId& b) const noexcept { return doHash(b); }
     };
 
     class BucketIdIdentityHasher : public BucketIdHasher {
-        size_t doHash(const document::BucketId& b) const override {
+        size_t doHash(const document::BucketId& b) const noexcept override {
             return b.getId();
         }
     };
diff --git a/storage/src/vespa/storage/distributor/bucketownership.h b/storage/src/vespa/storage/distributor/bucketownership.h
index 46b38b46bf7..89678e42375 100644
--- a/storage/src/vespa/storage/distributor/bucketownership.h
+++ b/storage/src/vespa/storage/distributor/bucketownership.h
@@ -12,15 +12,15 @@ class BucketOwnership
     const lib::ClusterState* _checkedState;
     bool _owned;
 
-    BucketOwnership(const lib::ClusterState& checkedState)
+    BucketOwnership(const lib::ClusterState& checkedState) noexcept
         : _checkedState(&checkedState),
           _owned(false)
     { }
 
 public:
-    BucketOwnership() : _checkedState(nullptr), _owned(true) {}
+    constexpr BucketOwnership() noexcept : _checkedState(nullptr), _owned(true) {}
 
-    bool isOwned() const { return _owned; }
+    [[nodiscard]] bool isOwned() const noexcept { return _owned; }
     /**
      * Cluster state in which the ownership check failed. Lifetime of returned
      * reference depends on when the active or pending cluster state of the
@@ -30,16 +30,16 @@ public:
      *
      * Precondition: isOwned() == false
      */
-    const lib::ClusterState& getNonOwnedState() {
+    const lib::ClusterState& getNonOwnedState() noexcept {
         assert(!isOwned());
         return *_checkedState;
     }
 
-    static BucketOwnership createOwned() {
+    static constexpr BucketOwnership createOwned() noexcept {
         return BucketOwnership();
     }
 
-    static BucketOwnership createNotOwnedInState(const lib::ClusterState& s) {
+    static BucketOwnership createNotOwnedInState(const lib::ClusterState& s) noexcept {
         return BucketOwnership(s);
     }
 };
diff --git a/storage/src/vespa/storage/distributor/common/.gitignore b/storage/src/vespa/storage/distributor/common/.gitignore
deleted file mode 100644
index e69de29bb2d..00000000000
--- a/storage/src/vespa/storage/distributor/common/.gitignore
+++ /dev/null
diff --git a/storage/src/vespa/storage/distributor/distributor_bucket_space.h b/storage/src/vespa/storage/distributor/distributor_bucket_space.h
index 3dfd1e1ce30..f38556a664c 100644
--- a/storage/src/vespa/storage/distributor/distributor_bucket_space.h
+++ b/storage/src/vespa/storage/distributor/distributor_bucket_space.h
@@ -32,7 +32,7 @@ namespace storage::distributor {
  *   bucket spaces.
  */
 class DistributorBucketSpace {
-    std::unique_ptr<BucketDatabase>  _bucketDatabase;
+    std::unique_ptr<BucketDatabase>          _bucketDatabase;
     std::shared_ptr<const lib::ClusterState> _clusterState;
     std::shared_ptr<const lib::Distribution> _distribution;
     uint16_t                                 _node_index;
diff --git a/storage/src/vespa/storage/distributor/distributor_host_info_reporter.h b/storage/src/vespa/storage/distributor/distributor_host_info_reporter.h
index 6680059b3d6..412867b537f 100644
--- a/storage/src/vespa/storage/distributor/distributor_host_info_reporter.h
+++ b/storage/src/vespa/storage/distributor/distributor_host_info_reporter.h
@@ -4,8 +4,7 @@
 #include <vespa/storage/common/hostreporter/hostreporter.h>
 #include <atomic>
 
-namespace storage {
-namespace distributor {
+namespace storage::distributor {
 
 class BucketSpacesStatsProvider;
 class MinReplicaProvider;
@@ -46,6 +45,4 @@ private:
     std::atomic<bool> _enabled;
 };
 
-} // distributor
-} // storage
-
+} // storage::distributor
diff --git a/storage/src/vespa/storage/distributor/distributor_interface.h b/storage/src/vespa/storage/distributor/distributor_interface.h
index 083c49f4ae3..b66d3ea198f 100644
--- a/storage/src/vespa/storage/distributor/distributor_interface.h
+++ b/storage/src/vespa/storage/distributor/distributor_interface.h
@@ -14,7 +14,7 @@ class DistributorMetricSet;
  */
 class DistributorInterface : public DistributorMessageSender {
 public:
-    virtual ~DistributorInterface() {}
+    virtual ~DistributorInterface() = default;
     virtual DistributorMetricSet& metrics() = 0;
     virtual const DistributorConfiguration& config() const = 0;
 };
diff --git a/storage/src/vespa/storage/distributor/distributor_node_context.h b/storage/src/vespa/storage/distributor/distributor_node_context.h
index ad082a5a9e5..4e25a479456 100644
--- a/storage/src/vespa/storage/distributor/distributor_node_context.h
+++ b/storage/src/vespa/storage/distributor/distributor_node_context.h
@@ -17,7 +17,7 @@ namespace storage::distributor {
  */
 class DistributorNodeContext : public ClusterContext {
 public:
-    virtual ~DistributorNodeContext() {}
+    virtual ~DistributorNodeContext() = default;
     virtual const framework::Clock& clock() const noexcept = 0;
     virtual const document::BucketIdFactory& bucket_id_factory() const noexcept = 0;
     virtual uint16_t node_index() const noexcept = 0;
diff --git a/storage/src/vespa/storage/distributor/document_selection_parser.h b/storage/src/vespa/storage/distributor/document_selection_parser.h
index 3e7e0209429..45ca2bf1cde 100644
--- a/storage/src/vespa/storage/distributor/document_selection_parser.h
+++ b/storage/src/vespa/storage/distributor/document_selection_parser.h
@@ -14,7 +14,7 @@ namespace storage::distributor {
  */
 class DocumentSelectionParser {
 public:
-    virtual ~DocumentSelectionParser() {}
+    virtual ~DocumentSelectionParser() = default;
     virtual std::unique_ptr<document::select::Node> parse_selection(const vespalib::string& str) const = 0;
 };
 
diff --git a/storage/src/vespa/storage/distributor/externaloperationhandler.h b/storage/src/vespa/storage/distributor/externaloperationhandler.h
index 076b182abdd..50a2019a2ae 100644
--- a/storage/src/vespa/storage/distributor/externaloperationhandler.h
+++ b/storage/src/vespa/storage/distributor/externaloperationhandler.h
@@ -11,17 +11,17 @@
 
 namespace documentapi { class TestAndSetCondition; }
 namespace storage::lib { class ClusterState; }
-namespace storage { class PersistenceOperationMetricSet; }
 
 namespace storage::distributor {
 
 class DistributorMetricSet;
-class TopLevelDistributor;
-class MaintenanceOperationGenerator;
 class DirectDispatchSender;
-class SequencingHandle;
+class MaintenanceOperationGenerator;
 class OperationSequencer;
 class OperationOwner;
+class PersistenceOperationMetricSet;
+class SequencingHandle;
+class TopLevelDistributor;
 class UuidGenerator;
 
 class ExternalOperationHandler : public api::MessageHandler
diff --git a/storage/src/vespa/storage/distributor/ideal_service_layer_nodes_bundle.h b/storage/src/vespa/storage/distributor/ideal_service_layer_nodes_bundle.h
index 2d77cf0c996..f98c4699eef 100644
--- a/storage/src/vespa/storage/distributor/ideal_service_layer_nodes_bundle.h
+++ b/storage/src/vespa/storage/distributor/ideal_service_layer_nodes_bundle.h
@@ -17,12 +17,20 @@ public:
     IdealServiceLayerNodesBundle() noexcept;
     ~IdealServiceLayerNodesBundle();
 
-    void set_available_nodes(std::vector<uint16_t> available_nodes) { _available_nodes = std::move(available_nodes); }
-    void set_available_nonretired_nodes(std::vector<uint16_t> available_nonretired_nodes) { _available_nonretired_nodes = std::move(available_nonretired_nodes); }
-    void set_available_nonretired_or_maintenance_nodes(std::vector<uint16_t> available_nonretired_or_maintenance_nodes) { _available_nonretired_or_maintenance_nodes = std::move(available_nonretired_or_maintenance_nodes); }
+    void set_available_nodes(std::vector<uint16_t> available_nodes) {
+        _available_nodes = std::move(available_nodes);
+    }
+    void set_available_nonretired_nodes(std::vector<uint16_t> available_nonretired_nodes) {
+        _available_nonretired_nodes = std::move(available_nonretired_nodes);
+    }
+    void set_available_nonretired_or_maintenance_nodes(std::vector<uint16_t> available_nonretired_or_maintenance_nodes) {
+        _available_nonretired_or_maintenance_nodes = std::move(available_nonretired_or_maintenance_nodes);
+    }
     std::vector<uint16_t> get_available_nodes() const { return _available_nodes; }
     std::vector<uint16_t> get_available_nonretired_nodes() const { return _available_nonretired_nodes; }
-    std::vector<uint16_t> get_available_nonretired_or_maintenance_nodes() const { return _available_nonretired_or_maintenance_nodes; }
+    std::vector<uint16_t> get_available_nonretired_or_maintenance_nodes() const {
+        return _available_nonretired_or_maintenance_nodes;
+    }
 };
 
 }
diff --git a/storage/src/vespa/storage/distributor/idealstatemanager.cpp b/storage/src/vespa/storage/distributor/idealstatemanager.cpp
index 728040da50e..cf255b5ec18 100644
--- a/storage/src/vespa/storage/distributor/idealstatemanager.cpp
+++ b/storage/src/vespa/storage/distributor/idealstatemanager.cpp
@@ -27,16 +27,15 @@ IdealStateManager::IdealStateManager(
         DistributorStripeOperationContext& op_ctx,
         IdealStateMetricSet& metrics)
     : _metrics(metrics),
+      _stateCheckers(),
+      _splitBucketStateChecker(nullptr),
       _node_ctx(node_ctx),
       _op_ctx(op_ctx),
       _has_logged_phantom_replica_warning(false)
 {
-    LOG(debug, "Adding BucketStateStateChecker to state checkers");
     _stateCheckers.emplace_back(std::make_shared<BucketStateStateChecker>());
-
     _stateCheckers.emplace_back(std::make_shared<SplitBucketStateChecker>());
     _splitBucketStateChecker = dynamic_cast<SplitBucketStateChecker *>(_stateCheckers.back().get());
-
     _stateCheckers.emplace_back(std::make_shared<SplitInconsistentStateChecker>());
     _stateCheckers.emplace_back(std::make_shared<SynchronizeAndMoveStateChecker>());
     _stateCheckers.emplace_back(std::make_shared<JoinBucketsStateChecker>());
@@ -141,7 +140,7 @@ void IdealStateManager::verify_only_live_nodes_in_context(const StateChecker::Co
 
 StateChecker::Result
 IdealStateManager::generateHighestPriority(
-        const document::Bucket &bucket,
+        const document::Bucket& bucket,
         NodeMaintenanceStatsTracker& statsTracker) const
 {
     auto& distributorBucketSpace = _op_ctx.bucket_space_repo().get(bucket.getBucketSpace());
@@ -162,7 +161,7 @@ IdealStateManager::generateHighestPriority(
 
 MaintenancePriorityAndType
 IdealStateManager::prioritize(
-        const document::Bucket &bucket,
+        const document::Bucket& bucket,
         NodeMaintenanceStatsTracker& statsTracker) const
 {
     StateChecker::Result generated(generateHighestPriority(bucket, statsTracker));
@@ -198,7 +197,7 @@ IdealStateManager::generateInterceptingSplit(BucketSpace bucketSpace,
 }
 
 MaintenanceOperation::SP
-IdealStateManager::generate(const document::Bucket &bucket) const
+IdealStateManager::generate(const document::Bucket& bucket) const
 {
     NodeMaintenanceStatsTracker statsTracker;
     IdealStateOperation::SP op(
diff --git a/storage/src/vespa/storage/distributor/idealstatemanager.h b/storage/src/vespa/storage/distributor/idealstatemanager.h
index 32349541de2..0c9e3ffa1c6 100644
--- a/storage/src/vespa/storage/distributor/idealstatemanager.h
+++ b/storage/src/vespa/storage/distributor/idealstatemanager.h
@@ -42,15 +42,15 @@ public:
 
     // MaintenancePriorityGenerator interface
     MaintenancePriorityAndType prioritize(
-            const document::Bucket &bucket,
+            const document::Bucket& bucket,
             NodeMaintenanceStatsTracker& statsTracker) const override;
 
     // MaintenanceOperationGenerator
-    MaintenanceOperation::SP generate(const document::Bucket &bucket) const override;
+    MaintenanceOperation::SP generate(const document::Bucket& bucket) const override;
 
     // MaintenanceOperationGenerator
     std::vector<MaintenanceOperation::SP> generateAll(
-            const document::Bucket &bucket,
+            const document::Bucket& bucket,
             NodeMaintenanceStatsTracker& statsTracker) const override;
 
     /**
@@ -62,49 +62,43 @@ public:
             const BucketDatabase::Entry& e,
             api::StorageMessage::Priority pri);
 
-    IdealStateMetricSet& getMetrics() { return _metrics; }
-
+    IdealStateMetricSet& getMetrics() noexcept { return _metrics; }
 
     void dump_bucket_space_db_status(document::BucketSpace bucket_space, std::ostream& out) const;
 
     void getBucketStatus(std::ostream& out) const;
 
-    const DistributorNodeContext& node_context() const { return _node_ctx; }
-    DistributorStripeOperationContext& operation_context() { return _op_ctx; }
-    const DistributorStripeOperationContext& operation_context() const { return _op_ctx; }
-    DistributorBucketSpaceRepo &getBucketSpaceRepo() { return _op_ctx.bucket_space_repo(); }
-    const DistributorBucketSpaceRepo &getBucketSpaceRepo() const { return _op_ctx.bucket_space_repo(); }
+    const DistributorNodeContext& node_context() const noexcept { return _node_ctx; }
+    DistributorStripeOperationContext& operation_context() noexcept { return _op_ctx; }
+    const DistributorStripeOperationContext& operation_context() const noexcept { return _op_ctx; }
+    DistributorBucketSpaceRepo &getBucketSpaceRepo() noexcept { return _op_ctx.bucket_space_repo(); }
+    const DistributorBucketSpaceRepo &getBucketSpaceRepo() const noexcept { return _op_ctx.bucket_space_repo(); }
 
 private:
     void verify_only_live_nodes_in_context(const StateChecker::Context& c) const;
     static void fillParentAndChildBuckets(StateChecker::Context& c);
     static void fillSiblingBucket(StateChecker::Context& c);
     StateChecker::Result generateHighestPriority(
-            const document::Bucket &bucket,
+            const document::Bucket& bucket,
             NodeMaintenanceStatsTracker& statsTracker) const;
     StateChecker::Result runStateCheckers(StateChecker::Context& c) const;
 
     static BucketDatabase::Entry* getEntryForPrimaryBucket(StateChecker::Context& c);
 
-    IdealStateMetricSet& _metrics;
-    document::BucketId _lastPrioritizedBucket;
-
-    // Prioritized of state checkers that generate operations
-    // for idealstatemanager.
-    std::vector<StateChecker::SP> _stateCheckers;
-    SplitBucketStateChecker* _splitBucketStateChecker;
-
-    const DistributorNodeContext& _node_ctx;
+    IdealStateMetricSet&               _metrics;
+    std::vector<StateChecker::SP>      _stateCheckers;
+    SplitBucketStateChecker*           _splitBucketStateChecker;
+    const DistributorNodeContext&      _node_ctx;
     DistributorStripeOperationContext& _op_ctx;
-    mutable bool _has_logged_phantom_replica_warning;
+    mutable bool                       _has_logged_phantom_replica_warning;
 
     class StatusBucketVisitor : public BucketDatabase::EntryProcessor {
         // Stats tracker to use for all generateAll() calls to avoid having
         // to create a new hash map for each single bucket processed.
         NodeMaintenanceStatsTracker _statsTracker;
-        const IdealStateManager   & _ism;
+        const IdealStateManager&    _ism;
         document::BucketSpace       _bucketSpace;
-        std::ostream              & _out;
+        std::ostream&               _out;
     public:
         StatusBucketVisitor(const IdealStateManager& ism, document::BucketSpace bucketSpace, std::ostream& out)
             : _statsTracker(), _ism(ism), _bucketSpace(bucketSpace), _out(out) {}
diff --git a/storage/src/vespa/storage/distributor/idealstatemetricsset.h b/storage/src/vespa/storage/distributor/idealstatemetricsset.h
index 8062a65a01a..6528ad7dc72 100644
--- a/storage/src/vespa/storage/distributor/idealstatemetricsset.h
+++ b/storage/src/vespa/storage/distributor/idealstatemetricsset.h
@@ -6,9 +6,7 @@
 #include <vespa/metrics/countmetric.h>
 #include <vespa/storage/distributor/operations/idealstate/idealstateoperation.h>
 
-namespace storage {
-
-namespace distributor {
+namespace storage::distributor {
 
 class OperationMetricSet : public metrics::MetricSet
 {
@@ -50,7 +48,7 @@ public:
     metrics::LongValueMetric buckets_toomanycopies;
     metrics::LongValueMetric buckets;
     metrics::LongValueMetric buckets_notrusted;
-    metrics::LongValueMetric buckets_rechecking; // TODO remove, not used (but exposed by VespaMetricSet)
+    metrics::LongValueMetric buckets_rechecking; // TODO Vespa 9: remove, not used (but exposed by VespaMetricSet)
     metrics::LongValueMetric buckets_replicas_moving_out;
     metrics::LongValueMetric buckets_replicas_copying_in;
     metrics::LongValueMetric buckets_replicas_copying_out;
@@ -66,7 +64,4 @@ public:
     void setPendingOperations(const std::vector<uint64_t>& newMetrics);
 };
 
-}
-
-}
-
+} // storage::distributor
diff --git a/storage/src/vespa/storage/distributor/maintenance/bucketprioritydatabase.h b/storage/src/vespa/storage/distributor/maintenance/bucketprioritydatabase.h
index 4c193492f43..f2f4b7cc275 100644
--- a/storage/src/vespa/storage/distributor/maintenance/bucketprioritydatabase.h
+++ b/storage/src/vespa/storage/distributor/maintenance/bucketprioritydatabase.h
@@ -14,9 +14,9 @@ protected:
     {
     public:
         virtual ~ConstIteratorImpl() = default;
-        virtual void increment() = 0;
-        virtual bool equal(const ConstIteratorImpl& other) const = 0;
-        virtual PrioritizedBucket dereference() const = 0;
+        virtual void increment() noexcept = 0;
+        virtual bool equal(const ConstIteratorImpl& other) const noexcept = 0;
+        virtual PrioritizedBucket dereference() const noexcept = 0;
     };
 
     using ConstIteratorImplPtr = std::unique_ptr<ConstIteratorImpl>;
@@ -31,25 +31,25 @@ public:
     {
         ConstIteratorImplPtr _impl;
     public:
-        explicit ConstIterator(ConstIteratorImplPtr impl)
+        explicit ConstIterator(ConstIteratorImplPtr impl) noexcept
             : _impl(std::move(impl))
         {}
         ConstIterator(const ConstIterator &) = delete;
-        ConstIterator(ConstIterator &&) = default;
+        ConstIterator(ConstIterator &&) noexcept = default;
 
         virtual ~ConstIterator() = default;
     private:
         friend class boost::iterator_core_access;
 
-        void increment() {
+        void increment() noexcept {
             _impl->increment();
         }
 
-        bool equal(const ConstIterator& other) const {
+        [[nodiscard]] bool equal(const ConstIterator& other) const noexcept {
             return _impl->equal(*other._impl);
         }
 
-        PrioritizedBucket dereference() const {
+        PrioritizedBucket dereference() const noexcept {
             return _impl->dereference();
         }
     };
@@ -59,7 +59,7 @@ public:
     virtual ~BucketPriorityDatabase() = default;
     
     virtual const_iterator begin() const = 0;
-    virtual const_iterator end() const  = 0;
+    virtual const_iterator end() const = 0;
     virtual void setPriority(const PrioritizedBucket&) = 0;
 };
 
diff --git a/storage/src/vespa/storage/distributor/maintenance/maintenancepriority.h b/storage/src/vespa/storage/distributor/maintenance/maintenancepriority.h
index aa4f7b715f9..bb7ec904c16 100644
--- a/storage/src/vespa/storage/distributor/maintenance/maintenancepriority.h
+++ b/storage/src/vespa/storage/distributor/maintenance/maintenancepriority.h
@@ -20,33 +20,33 @@ public:
     static constexpr const char* toString(Priority pri) noexcept {
         switch (pri) {
         case NO_MAINTENANCE_NEEDED: return "NO_MAINTENANCE_NEEDED";
-        case VERY_LOW: return "VERY_LOW";
-        case LOW: return "LOW";
-        case MEDIUM: return "MEDIUM";
-        case HIGH: return "HIGH";
-        case VERY_HIGH: return "VERY_HIGH";
-        case HIGHEST: return "HIGHEST";
-        default: return "INVALID";
+        case VERY_LOW:              return "VERY_LOW";
+        case LOW:                   return "LOW";
+        case MEDIUM:                return "MEDIUM";
+        case HIGH:                  return "HIGH";
+        case VERY_HIGH:             return "VERY_HIGH";
+        case HIGHEST:               return "HIGHEST";
+        default:                    return "INVALID";
         }
     }
 
-    MaintenancePriority()
+    constexpr MaintenancePriority() noexcept
         : _priority(NO_MAINTENANCE_NEEDED)
     {}
 
-    explicit MaintenancePriority(Priority priority)
+    constexpr explicit MaintenancePriority(Priority priority) noexcept
         : _priority(priority)
     {}
 
-    Priority getPriority() const {
+    constexpr Priority getPriority() const noexcept {
         return _priority;
     }
 
-    bool requiresMaintenance() const {
+    constexpr bool requiresMaintenance() const noexcept {
         return _priority != NO_MAINTENANCE_NEEDED;
     }
 
-    static MaintenancePriority noMaintenanceNeeded() {
+    static constexpr MaintenancePriority noMaintenanceNeeded() noexcept {
         return MaintenancePriority(NO_MAINTENANCE_NEEDED);
     }
 
diff --git a/storage/src/vespa/storage/distributor/maintenance/maintenancepriorityandtype.h b/storage/src/vespa/storage/distributor/maintenance/maintenancepriorityandtype.h
index 68602958815..3be7a4a18a7 100644
--- a/storage/src/vespa/storage/distributor/maintenance/maintenancepriorityandtype.h
+++ b/storage/src/vespa/storage/distributor/maintenance/maintenancepriorityandtype.h
@@ -11,21 +11,21 @@ class MaintenancePriorityAndType
     MaintenancePriority _priority;
     MaintenanceOperation::Type _type;
 public:
-    MaintenancePriorityAndType(MaintenancePriority pri,
-                               MaintenanceOperation::Type type)
+    constexpr MaintenancePriorityAndType(MaintenancePriority pri,
+                                         MaintenanceOperation::Type type) noexcept
         : _priority(pri),
           _type(type)
     {}
 
-    const MaintenancePriority& getPriority() const {
+    constexpr MaintenancePriority getPriority() const noexcept {
         return _priority;
     }
 
-    MaintenanceOperation::Type getType() const {
+    constexpr MaintenanceOperation::Type getType() const noexcept {
         return _type;
     }
 
-    bool requiresMaintenance() const {
+    constexpr bool requiresMaintenance() const noexcept {
         return (_priority.getPriority()
                 != MaintenancePriority::NO_MAINTENANCE_NEEDED);
     }
diff --git a/storage/src/vespa/storage/distributor/maintenance/maintenancescanner.h b/storage/src/vespa/storage/distributor/maintenance/maintenancescanner.h
index 3d5280e3b5a..4fec2e57cbc 100644
--- a/storage/src/vespa/storage/distributor/maintenance/maintenancescanner.h
+++ b/storage/src/vespa/storage/distributor/maintenance/maintenancescanner.h
@@ -17,9 +17,9 @@ public:
         BucketDatabase::Entry _entry;
 
     public:
-        bool isDone() const { return _done; }
-        document::BucketSpace getBucketSpace() const { return _bucketSpace; }
-        const BucketDatabase::Entry& getEntry() const { return _entry; }
+        [[nodiscard]] bool isDone() const noexcept { return _done; }
+        document::BucketSpace getBucketSpace() const noexcept { return _bucketSpace; }
+        const BucketDatabase::Entry& getEntry() const noexcept { return _entry; }
 
         static ScanResult createDone() { return ScanResult(true); }
         static ScanResult createNotDone(document::BucketSpace bucketSpace, BucketDatabase::Entry entry) {
@@ -27,7 +27,7 @@ public:
         }
 
     private:
-        ScanResult(bool done) : _done(done), _bucketSpace(document::BucketSpace::invalid()), _entry() {}
+        explicit ScanResult(bool done) : _done(done), _bucketSpace(document::BucketSpace::invalid()), _entry() {}
         ScanResult(document::BucketSpace bucketSpace, const BucketDatabase::Entry& e) : _done(false), _bucketSpace(bucketSpace), _entry(e) {}
     };
 
diff --git a/storage/src/vespa/storage/distributor/maintenance/prioritizedbucket.h b/storage/src/vespa/storage/distributor/maintenance/prioritizedbucket.h
index 77f117803ec..e1660df7cdb 100644
--- a/storage/src/vespa/storage/distributor/maintenance/prioritizedbucket.h
+++ b/storage/src/vespa/storage/distributor/maintenance/prioritizedbucket.h
@@ -14,24 +14,24 @@ public:
 
     static const PrioritizedBucket INVALID;
 
-    PrioritizedBucket()
+    PrioritizedBucket() noexcept
         : _bucket(),
           _priority(MaintenancePriority::NO_MAINTENANCE_NEEDED)
     {}
 
-    PrioritizedBucket(const document::Bucket &bucket, Priority pri)
+    PrioritizedBucket(const document::Bucket &bucket, Priority pri) noexcept
         : _bucket(bucket),
           _priority(pri)
     {
     }
 
-    document::Bucket getBucket() const { return _bucket; }
+    document::Bucket getBucket() const noexcept { return _bucket; }
 
-    Priority getPriority() const {
+    Priority getPriority() const noexcept {
         return _priority;
     }
 
-    bool valid() const {
+    [[nodiscard]] bool valid() const noexcept {
         return _bucket.getBucketId().getRawId() != 0;
     }
 
@@ -41,19 +41,19 @@ public:
                                      MaintenancePriority::toString(_priority));
     }
 
-    bool operator==(const PrioritizedBucket& other) const {
+    bool operator==(const PrioritizedBucket& other) const noexcept {
         return _bucket == other._bucket && _priority == other._priority;
     }
 
-    bool requiresMaintenance() const {
+    [[nodiscard]] bool requiresMaintenance() const noexcept {
         return _priority != MaintenancePriority::NO_MAINTENANCE_NEEDED;
     }
 
-    bool moreImportantThan(const PrioritizedBucket& other) const {
+    [[nodiscard]] bool moreImportantThan(const PrioritizedBucket& other) const noexcept {
         return _priority > other._priority;
     }
 
-    bool moreImportantThan(Priority otherPri) const {
+    [[nodiscard]] bool moreImportantThan(Priority otherPri) const noexcept {
         return _priority > otherPri;
     }
 
diff --git a/storage/src/vespa/storage/distributor/maintenance/simplebucketprioritydatabase.cpp b/storage/src/vespa/storage/distributor/maintenance/simplebucketprioritydatabase.cpp
index e267626fd7f..d5104aefea7 100644
--- a/storage/src/vespa/storage/distributor/maintenance/simplebucketprioritydatabase.cpp
+++ b/storage/src/vespa/storage/distributor/maintenance/simplebucketprioritydatabase.cpp
@@ -42,7 +42,7 @@ SimpleBucketPriorityDatabase::setPriority(const PrioritizedBucket& bucket)
 }
 
 void
-SimpleBucketPriorityDatabase::PriFifoMappingConstIteratorImpl::increment()
+SimpleBucketPriorityDatabase::PriFifoMappingConstIteratorImpl::increment() noexcept
 {
     if (_pri_fifo_iter != _pri_fifo_end) {
         ++_pri_fifo_iter;
@@ -50,14 +50,14 @@ SimpleBucketPriorityDatabase::PriFifoMappingConstIteratorImpl::increment()
 }
 
 bool
-SimpleBucketPriorityDatabase::PriFifoMappingConstIteratorImpl::equal(const ConstIteratorImpl& other) const
+SimpleBucketPriorityDatabase::PriFifoMappingConstIteratorImpl::equal(const ConstIteratorImpl& other) const noexcept
 {
     auto& typed_other = dynamic_cast<const PriFifoMappingConstIteratorImpl&>(other);
     return (_pri_fifo_iter == typed_other._pri_fifo_iter);
 }
 
 PrioritizedBucket
-SimpleBucketPriorityDatabase::PriFifoMappingConstIteratorImpl::dereference() const
+SimpleBucketPriorityDatabase::PriFifoMappingConstIteratorImpl::dereference() const noexcept
 {
     assert(_pri_fifo_iter != _pri_fifo_end);
     return {_pri_fifo_iter->second, _pri_fifo_iter->first._pri};
diff --git a/storage/src/vespa/storage/distributor/maintenance/simplebucketprioritydatabase.h b/storage/src/vespa/storage/distributor/maintenance/simplebucketprioritydatabase.h
index aa2605e94ca..50bcadf4e18 100644
--- a/storage/src/vespa/storage/distributor/maintenance/simplebucketprioritydatabase.h
+++ b/storage/src/vespa/storage/distributor/maintenance/simplebucketprioritydatabase.h
@@ -50,15 +50,15 @@ private:
         PriFifoBucketMap::const_iterator _pri_fifo_end;
     public:
         PriFifoMappingConstIteratorImpl(PriFifoBucketMap::const_iterator pri_fifo_iter,
-                                        PriFifoBucketMap::const_iterator pri_fifo_end)
+                                        PriFifoBucketMap::const_iterator pri_fifo_end) noexcept
             : _pri_fifo_iter(pri_fifo_iter),
               _pri_fifo_end(pri_fifo_end)
         {}
         ~PriFifoMappingConstIteratorImpl() override = default;
 
-        void increment() override;
-        bool equal(const ConstIteratorImpl& other) const override;
-        PrioritizedBucket dereference() const override;
+        void increment() noexcept override;
+        bool equal(const ConstIteratorImpl& other) const noexcept override;
+        PrioritizedBucket dereference() const noexcept override;
     };
 
     void clearAllEntriesForBucket(const document::Bucket &bucket);
diff --git a/storage/src/vespa/storage/distributor/maintenance/simplemaintenancescanner.h b/storage/src/vespa/storage/distributor/maintenance/simplemaintenancescanner.h
index a66cae11477..a867d4a5267 100644
--- a/storage/src/vespa/storage/distributor/maintenance/simplemaintenancescanner.h
+++ b/storage/src/vespa/storage/distributor/maintenance/simplemaintenancescanner.h
@@ -33,12 +33,12 @@ public:
         void merge(const PendingMaintenanceStats& rhs);
     };
 private:
-    BucketPriorityDatabase& _bucketPriorityDb;
-    const MaintenancePriorityGenerator& _priorityGenerator;
-    const DistributorBucketSpaceRepo& _bucketSpaceRepo;
+    BucketPriorityDatabase&                                    _bucketPriorityDb;
+    const MaintenancePriorityGenerator&                        _priorityGenerator;
+    const DistributorBucketSpaceRepo&                          _bucketSpaceRepo;
     DistributorBucketSpaceRepo::BucketSpaceMap::const_iterator _bucketSpaceItr;
-    document::BucketId _bucketCursor;
-    PendingMaintenanceStats _pendingMaintenance;
+    document::BucketId                                         _bucketCursor;
+    PendingMaintenanceStats                                    _pendingMaintenance;
 
     void countBucket(document::BucketSpace bucketSpace, const BucketInfo &info);
 public:
@@ -55,7 +55,7 @@ public:
     // TODO: move out into own interface!
     void prioritizeBucket(const document::Bucket &id);
 
-    const PendingMaintenanceStats& getPendingMaintenanceStats() const {
+    const PendingMaintenanceStats& getPendingMaintenanceStats() const noexcept {
         return _pendingMaintenance;
     }
 };
diff --git a/storage/src/vespa/storage/distributor/messageguard.h b/storage/src/vespa/storage/distributor/messageguard.h
deleted file mode 100644
index 2ed75d22577..00000000000
--- a/storage/src/vespa/storage/distributor/messageguard.h
+++ /dev/null
@@ -1,45 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#pragma once
-
-#include "pendingclusterstate.h"
-#include <vespa/storage/common/messagesender.h>
-
-namespace storage {
-
-class MessageGuard {
-    std::vector<std::shared_ptr<api::StorageMessage> > messagesUp;
-    std::vector<std::shared_ptr<api::StorageMessage> > messagesDown;
-
-    std::unique_lock<std::mutex> _lock;
-    ChainedMessageSender& _messageSender;
-
-public:
-    MessageGuard(std::mutex & lock, ChainedMessageSender& messageSender)
-        : _lock(lock),
-          _messageSender(messageSender) {}
-
-    void send(const std::shared_ptr<api::StorageMessage>& message) {
-        sendUp(message);
-    }
-
-    void sendUp(const std::shared_ptr<api::StorageMessage>& message) {
-        messagesUp.push_back(message);
-    }
-
-    void sendDown(const std::shared_ptr<api::StorageMessage>& message) {
-        messagesDown.push_back(message);
-    }
-
-    ~MessageGuard() {
-        _lock.unlock();
-        for (uint32_t i = 0; i < messagesUp.size(); i++) {
-            _messageSender.sendUp(messagesUp[i]);
-        }
-        for (uint32_t i = 0; i < messagesDown.size(); i++) {
-            _messageSender.sendDown(messagesDown[i]);
-        }
-    }
-};
-
-}
-
diff --git a/storage/src/vespa/storage/distributor/messagetracker.h b/storage/src/vespa/storage/distributor/messagetracker.h
index d3d6899a854..73e2461eb7a 100644
--- a/storage/src/vespa/storage/distributor/messagetracker.h
+++ b/storage/src/vespa/storage/distributor/messagetracker.h
@@ -25,11 +25,11 @@ public:
         uint16_t _target;
     };
 
-    MessageTracker(const ClusterContext &cluster_context);
-    MessageTracker(MessageTracker &&) = default;
-    MessageTracker & operator = (MessageTracker &&) = delete;
+    MessageTracker(const ClusterContext& cluster_context);
+    MessageTracker(MessageTracker&&) = default;
+    MessageTracker& operator=(MessageTracker&&) = delete;
     MessageTracker(const MessageTracker &) = delete;
-    MessageTracker & operator = (const MessageTracker &) = delete;
+    MessageTracker& operator=(const MessageTracker&) = delete;
     ~MessageTracker();
 
     void queueCommand(std::shared_ptr<api::BucketCommand> msg, uint16_t target) {
@@ -49,11 +49,10 @@ public:
     bool finished();
 
 protected:
-    std::vector<ToSend> _commandQueue;
-
+    std::vector<ToSend>          _commandQueue;
     // Keeps track of which node a message was sent to.
     std::map<uint64_t, uint16_t> _sentMessages;
-    const ClusterContext &_cluster_ctx;
+    const ClusterContext&        _cluster_ctx;
 };
 
 }
diff --git a/storage/src/vespa/storage/distributor/operationowner.cpp b/storage/src/vespa/storage/distributor/operationowner.cpp
index c118209353b..81512393c5b 100644
--- a/storage/src/vespa/storage/distributor/operationowner.cpp
+++ b/storage/src/vespa/storage/distributor/operationowner.cpp
@@ -11,9 +11,7 @@ LOG_SETUP(".operationowner");
 
 namespace storage::distributor {
 
-OperationOwner::~OperationOwner()
-{
-}
+OperationOwner::~OperationOwner() = default;
 
 void
 OperationOwner::Sender::sendCommand(const std::shared_ptr<api::StorageCommand> & msg)
diff --git a/storage/src/vespa/storage/distributor/operations/external/getoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/getoperation.cpp
index da53d48d461..41260115297 100644
--- a/storage/src/vespa/storage/distributor/operations/external/getoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/getoperation.cpp
@@ -18,7 +18,7 @@ using document::BucketSpace;
 
 namespace storage::distributor {
 
-GetOperation::GroupId::GroupId(const document::BucketId& id, uint32_t checksum, int node)
+GetOperation::GroupId::GroupId(const document::BucketId& id, uint32_t checksum, int node) noexcept
     : _id(id),
       _checksum(checksum),
       _node(node)
@@ -26,7 +26,7 @@ GetOperation::GroupId::GroupId(const document::BucketId& id, uint32_t checksum,
 }
 
 bool
-GetOperation::GroupId::operator<(const GroupId& other) const
+GetOperation::GroupId::operator<(const GroupId& other) const noexcept
 {
     if (_id.getRawId() != other._id.getRawId()) {
         return (_id.getRawId() < other._id.getRawId());
@@ -41,7 +41,7 @@ GetOperation::GroupId::operator<(const GroupId& other) const
 }
 
 bool
-GetOperation::GroupId::operator==(const GroupId& other) const
+GetOperation::GroupId::operator==(const GroupId& other) const noexcept
 {
     return (_id == other._id
             && _checksum == other._checksum
@@ -279,7 +279,7 @@ GetOperation::assignTargetNodeGroups(const BucketDatabase::ReadGuard& read_guard
 }
 
 bool
-GetOperation::all_bucket_metadata_initially_consistent() const
+GetOperation::all_bucket_metadata_initially_consistent() const noexcept
 {
     // TODO rename, calling this "responses" is confusing as it's populated before sending anything.
     return _responses.size() == 1;
diff --git a/storage/src/vespa/storage/distributor/operations/external/getoperation.h b/storage/src/vespa/storage/distributor/operations/external/getoperation.h
index 61443100695..96b5d970904 100644
--- a/storage/src/vespa/storage/distributor/operations/external/getoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/getoperation.h
@@ -12,16 +12,13 @@
 
 namespace document { class Document; }
 
-namespace storage {
+namespace storage::api { class GetCommand; }
 
-namespace api { class GetCommand; }
-
-class PersistenceOperationMetricSet;
-
-namespace distributor {
+namespace storage::distributor {
 
 class DistributorNodeContext;
 class DistributorBucketSpace;
+class PersistenceOperationMetricSet;
 
 class GetOperation  : public Operation
 {
@@ -36,11 +33,11 @@ public:
     void onClose(DistributorStripeMessageSender& sender) override;
     void onStart(DistributorStripeMessageSender& sender) override;
     void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> & msg) override;
-    const char* getName() const override { return "get"; }
+    const char* getName() const noexcept override { return "get"; }
     std::string getStatus() const override { return ""; }
 
-    bool all_bucket_metadata_initially_consistent() const;
-    bool any_replicas_failed() const noexcept {
+    [[nodiscard]] bool all_bucket_metadata_initially_consistent() const noexcept;
+    [[nodiscard]] bool any_replicas_failed() const noexcept {
         return _any_replicas_failed;
     }
 
@@ -66,12 +63,12 @@ private:
     class GroupId {
     public:
         // Node should be set only if bucket is incomplete
-        GroupId(const document::BucketId& id, uint32_t checksum, int node);
+        GroupId(const document::BucketId& id, uint32_t checksum, int node) noexcept;
 
-        bool operator<(const GroupId& other) const;
-        bool operator==(const GroupId& other) const;
-        const document::BucketId& getBucketId() const { return _id; }
-        int getNode() const { return _node; }
+        bool operator<(const GroupId& other) const noexcept;
+        bool operator==(const GroupId& other) const noexcept;
+        const document::BucketId& getBucketId() const noexcept { return _id; }
+        int getNode() const noexcept { return _node; }
     private:
         document::BucketId _id;
         uint32_t _checksum;
@@ -129,4 +126,3 @@ private:
 };
 
 }
-}
diff --git a/storage/src/vespa/storage/distributor/operations/external/putoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/putoperation.cpp
index 74ff8371fbe..dea215f47dc 100644
--- a/storage/src/vespa/storage/distributor/operations/external/putoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/putoperation.cpp
@@ -24,7 +24,7 @@ using document::BucketSpace;
 
 PutOperation::PutOperation(const DistributorNodeContext& node_ctx,
                            DistributorStripeOperationContext& op_ctx,
-                           DistributorBucketSpace &bucketSpace,
+                           DistributorBucketSpace& bucketSpace,
                            std::shared_ptr<api::PutCommand> msg,
                            PersistenceOperationMetricSet& metric, SequencingHandle sequencingHandle)
     : SequencedOperation(std::move(sequencingHandle)),
@@ -222,7 +222,7 @@ PutOperation::shouldImplicitlyActivateReplica(const OperationTargetList& targets
 }
 
 void
-PutOperation::onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> & msg)
+PutOperation::onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply>& msg)
 {
     LOG(debug, "Received %s", msg->toString(true).c_str());
     _tracker.receiveReply(sender, static_cast<api::BucketInfoReply&>(*msg));
diff --git a/storage/src/vespa/storage/distributor/operations/external/putoperation.h b/storage/src/vespa/storage/distributor/operations/external/putoperation.h
index 7ec81d6570d..9801fed0c99 100644
--- a/storage/src/vespa/storage/distributor/operations/external/putoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/putoperation.h
@@ -5,16 +5,15 @@
 #include <vespa/storage/distributor/operations/sequenced_operation.h>
 #include <vespa/storage/distributor/persistencemessagetracker.h>
 
-namespace document {
-    class Document;
-}
-namespace storage::lib {
-    class Distribution;
-}
+namespace document { class Document; }
+
+namespace storage::lib { class Distribution; }
+
 namespace storage::api {
-    class CreateBucketReply;
-    class PutCommand;
+class CreateBucketReply;
+class PutCommand;
 }
+
 namespace storage::distributor {
 
 class DistributorBucketSpace;
@@ -25,16 +24,16 @@ class PutOperation : public SequencedOperation
 public:
     PutOperation(const DistributorNodeContext& node_ctx,
                  DistributorStripeOperationContext& op_ctx,
-                 DistributorBucketSpace &bucketSpace,
+                 DistributorBucketSpace& bucketSpace,
                  std::shared_ptr<api::PutCommand> msg,
                  PersistenceOperationMetricSet& metric,
                  SequencingHandle sequencingHandle = SequencingHandle());
     ~PutOperation() override;
 
     void onStart(DistributorStripeMessageSender& sender) override;
-    const char* getName() const override { return "put"; };
+    const char* getName() const noexcept override { return "put"; };
     std::string getStatus() const override { return ""; };
-    void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> &) override;
+    void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply>&) override;
     void onClose(DistributorStripeMessageSender& sender) override;
 
 private:
diff --git a/storage/src/vespa/storage/distributor/operations/external/read_for_write_visitor_operation.h b/storage/src/vespa/storage/distributor/operations/external/read_for_write_visitor_operation.h
index dac9ed49bd3..f53342a9286 100644
--- a/storage/src/vespa/storage/distributor/operations/external/read_for_write_visitor_operation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/read_for_write_visitor_operation.h
@@ -41,7 +41,7 @@ public:
                                         UuidGenerator& uuid_generator);
     ~ReadForWriteVisitorOperationStarter() override;
 
-    const char* getName() const override { return "ReadForWriteVisitorOperationStarter"; }
+    const char* getName() const noexcept override { return "ReadForWriteVisitorOperationStarter"; }
     void onClose(DistributorStripeMessageSender& sender) override;
     void onStart(DistributorStripeMessageSender& sender) override;
     void onReceive(DistributorStripeMessageSender& sender,
diff --git a/storage/src/vespa/storage/distributor/operations/external/removelocationoperation.h b/storage/src/vespa/storage/distributor/operations/external/removelocationoperation.h
index 1f951904ea1..d177676ff03 100644
--- a/storage/src/vespa/storage/distributor/operations/external/removelocationoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/removelocationoperation.h
@@ -4,11 +4,9 @@
 #include <vespa/storage/distributor/operations/operation.h>
 #include <vespa/storage/distributor/persistencemessagetracker.h>
 
-namespace storage {
+namespace storage::api { class RemoveLocationCommand; }
 
-namespace api { class RemoveLocationCommand; }
-
-namespace distributor {
+namespace storage::distributor {
 
 class DistributorBucketSpace;
 
@@ -18,7 +16,7 @@ public:
     RemoveLocationOperation(const DistributorNodeContext& node_ctx,
                             DistributorStripeOperationContext& op_ctx,
                             const DocumentSelectionParser& parser,
-                            DistributorBucketSpace &bucketSpace,
+                            DistributorBucketSpace& bucketSpace,
                             std::shared_ptr<api::RemoveLocationCommand> msg,
                             PersistenceOperationMetricSet& metric);
     ~RemoveLocationOperation() override;
@@ -29,9 +27,9 @@ public:
                            const api::RemoveLocationCommand& cmd,
                            document::BucketId& id);
     void onStart(DistributorStripeMessageSender& sender) override;
-    const char* getName() const override { return "removelocation"; };
+    const char* getName() const noexcept override { return "removelocation"; };
     std::string getStatus() const override { return ""; };
-    void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> &) override;
+    void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply>&) override;
     void onClose(DistributorStripeMessageSender& sender) override;
 private:
     PersistenceMessageTrackerImpl _trackerInstance;
@@ -45,5 +43,3 @@ private:
 };
 
 }
-
-}
diff --git a/storage/src/vespa/storage/distributor/operations/external/removeoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/removeoperation.cpp
index 7beb95451e9..584ad9de2ce 100644
--- a/storage/src/vespa/storage/distributor/operations/external/removeoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/removeoperation.cpp
@@ -14,7 +14,7 @@ using document::BucketSpace;
 
 RemoveOperation::RemoveOperation(const DistributorNodeContext& node_ctx,
                                  DistributorStripeOperationContext& op_ctx,
-                                 DistributorBucketSpace &bucketSpace,
+                                 DistributorBucketSpace& bucketSpace,
                                  std::shared_ptr<api::RemoveCommand> msg,
                                  PersistenceOperationMetricSet& metric,
                                  SequencingHandle sequencingHandle)
@@ -81,7 +81,7 @@ RemoveOperation::onStart(DistributorStripeMessageSender& sender)
 void
 RemoveOperation::onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> & msg)
 {
-    api::RemoveReply& reply(static_cast<api::RemoveReply&>(*msg));
+    auto& reply = static_cast<api::RemoveReply&>(*msg);
 
     if (_tracker.getReply().get()) {
         api::RemoveReply& replyToSend =
diff --git a/storage/src/vespa/storage/distributor/operations/external/removeoperation.h b/storage/src/vespa/storage/distributor/operations/external/removeoperation.h
index 53de79ac9b3..360ab332f96 100644
--- a/storage/src/vespa/storage/distributor/operations/external/removeoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/removeoperation.h
@@ -4,42 +4,36 @@
 #include <vespa/storage/distributor/operations/sequenced_operation.h>
 #include <vespa/storage/distributor/persistencemessagetracker.h>
 
-namespace storage {
+namespace storage::api { class RemoveCommand; }
 
-namespace api { class RemoveCommand; }
-
-namespace distributor {
+namespace storage::distributor {
 
 class DistributorBucketSpace;
 
-class RemoveOperation  : public SequencedOperation
+class RemoveOperation : public SequencedOperation
 {
 public:
     RemoveOperation(const DistributorNodeContext& node_ctx,
                     DistributorStripeOperationContext& op_ctx,
-                    DistributorBucketSpace &bucketSpace,
+                    DistributorBucketSpace& bucketSpace,
                     std::shared_ptr<api::RemoveCommand> msg,
                     PersistenceOperationMetricSet& metric,
                     SequencingHandle sequencingHandle = SequencingHandle());
     ~RemoveOperation() override;
 
     void onStart(DistributorStripeMessageSender& sender) override;
-    const char* getName() const override { return "remove"; };
+    const char* getName() const noexcept override { return "remove"; };
     std::string getStatus() const override { return ""; };
 
     void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> &) override;
     void onClose(DistributorStripeMessageSender& sender) override;
 
 private:
-    PersistenceMessageTrackerImpl _trackerInstance;
-    PersistenceMessageTracker& _tracker;
-
+    PersistenceMessageTrackerImpl       _trackerInstance;
+    PersistenceMessageTracker&          _tracker;
     std::shared_ptr<api::RemoveCommand> _msg;
-
-    const DistributorNodeContext& _node_ctx;
-    DistributorBucketSpace &_bucketSpace;
+    const DistributorNodeContext&       _node_ctx;
+    DistributorBucketSpace&             _bucketSpace;
 };
 
 }
-
-}
diff --git a/storage/src/vespa/storage/distributor/operations/external/statbucketlistoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/statbucketlistoperation.cpp
index 8dd291c19bb..6b2550ab547 100644
--- a/storage/src/vespa/storage/distributor/operations/external/statbucketlistoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/statbucketlistoperation.cpp
@@ -19,6 +19,8 @@ StatBucketListOperation::StatBucketListOperation(
 {
 }
 
+StatBucketListOperation::~StatBucketListOperation() = default;
+
 void
 StatBucketListOperation::getBucketStatus(const BucketDatabase::Entry& entry,
                                          std::ostream& ost) const
@@ -42,20 +44,18 @@ StatBucketListOperation::getBucketStatus(const BucketDatabase::Entry& entry,
 void
 StatBucketListOperation::onStart(DistributorStripeMessageSender& sender)
 {
-    api::GetBucketListReply::SP reply(new api::GetBucketListReply(*_command));
+    auto reply = std::make_shared<api::GetBucketListReply>(*_command);
 
     std::vector<BucketDatabase::Entry> entries;
     _bucketDb.getAll(_command->getBucketId(), entries);
 
-    for (uint32_t i = 0; i < entries.size(); i++) {
+    for (const auto& entry : entries) {
         std::ostringstream ost;
         ost << "[distributor:" << _distributorIndex << "] ";
 
-        getBucketStatus(entries[i], ost);
+        getBucketStatus(entry, ost);
 
-        reply->getBuckets().push_back(api::GetBucketListReply::BucketInfo(
-                                              entries[i].getBucketId(),
-                                              ost.str()));
+        reply->getBuckets().emplace_back(entry.getBucketId(), ost.str());
     }
     sender.sendReply(reply);
 }
diff --git a/storage/src/vespa/storage/distributor/operations/external/statbucketlistoperation.h b/storage/src/vespa/storage/distributor/operations/external/statbucketlistoperation.h
index 9dcab1ee0f6..fe88ec50749 100644
--- a/storage/src/vespa/storage/distributor/operations/external/statbucketlistoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/statbucketlistoperation.h
@@ -5,11 +5,9 @@
 #include <vespa/storage/distributor/operations/operation.h>
 #include <vespa/storage/bucketdb/bucketdatabase.h>
 
-namespace storage {
+namespace storage::api { class GetBucketListCommand; }
 
-namespace api { class GetBucketListCommand; }
-
-namespace distributor {
+namespace storage::distributor {
 
 class MaintenanceOperationGenerator;
 
@@ -21,9 +19,9 @@ public:
             const MaintenanceOperationGenerator& generator,
             uint16_t distributorIndex,
             const std::shared_ptr<api::GetBucketListCommand>& cmd);
-    ~StatBucketListOperation() {}
+    ~StatBucketListOperation() override;
 
-    const char* getName() const override { return "statBucketList"; }
+    const char* getName() const noexcept override { return "statBucketList"; }
     std::string getStatus() const override { return ""; }
 
     void onStart(DistributorStripeMessageSender& sender) override;
@@ -43,5 +41,4 @@ private:
     std::shared_ptr<api::GetBucketListCommand> _command;
 };
 
-} // distributor
-} // storage
+} // storage::distributor
diff --git a/storage/src/vespa/storage/distributor/operations/external/statbucketoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/statbucketoperation.cpp
index 20cd8c67c29..85f36e7a963 100644
--- a/storage/src/vespa/storage/distributor/operations/external/statbucketoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/statbucketoperation.cpp
@@ -42,27 +42,19 @@ StatBucketOperation::onStart(DistributorStripeMessageSender& sender)
 
     // If no entries exist, give empty reply
     if (nodes.size() == 0) {
-        api::StatBucketReply::SP reply(new api::StatBucketReply(*_command, "Bucket was not stored on any nodes."));
+        auto reply = std::make_shared<api::StatBucketReply>(*_command, "Bucket was not stored on any nodes.");
         reply->setResult(api::ReturnCode(api::ReturnCode::OK));
         sender.sendReply(reply);
     } else {
-        std::vector<std::shared_ptr<api::StorageCommand> > messages;
-        for (uint32_t i = 0; i < nodes.size(); i++) {
-            std::shared_ptr<api::StatBucketCommand> cmd(
-                    new api::StatBucketCommand(
-                            _command->getBucket(),
-                            _command->getDocumentSelection()));
-
-            messages.push_back(cmd);
-            _sent[cmd->getMsgId()] = nodes[i];
+        std::vector<std::shared_ptr<api::StorageCommand>> messages;
+        for (uint16_t node : nodes) {
+            auto cmd = std::make_shared<api::StatBucketCommand>(_command->getBucket(), _command->getDocumentSelection());
+            _sent[cmd->getMsgId()] = node;
+            messages.emplace_back(std::move(cmd));
         }
 
         for (uint32_t i = 0; i < nodes.size(); i++) {
-            sender.sendToNode(
-                       lib::NodeType::STORAGE,
-                       nodes[i],
-                       messages[i],
-                       true);
+            sender.sendToNode(lib::NodeType::STORAGE, nodes[i], messages[i], true);
         }
     }
 };
@@ -71,9 +63,8 @@ void
 StatBucketOperation::onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> & msg)
 {
     assert(msg->getType() == api::MessageType::STATBUCKET_REPLY);
-    api::StatBucketReply& myreply(dynamic_cast<api::StatBucketReply&>(*msg));
-
-    std::map<uint64_t, uint16_t>::iterator found = _sent.find(msg->getMsgId());
+    auto& myreply = dynamic_cast<api::StatBucketReply&>(*msg);
+    auto found = _sent.find(msg->getMsgId());
 
     if (found != _sent.end()) {
         std::ostringstream ost;
@@ -83,19 +74,15 @@ StatBucketOperation::onReceive(DistributorStripeMessageSender& sender, const std
             ost << "\tBucket information retrieval failed on node " << found->second << ": " << myreply.getResult() << "\n\n";
         }
         _results[found->second] = ost.str();
-
         _sent.erase(found);
     }
 
     if (_sent.empty()) {
         std::ostringstream ost;
-        for (std::map<uint16_t, std::string>::iterator iter = _results.begin();
-             iter != _results.end();
-             iter++) {
-            ost << iter->second;
+        for (const auto& result : _results) {
+            ost << result.second;
         }
-
-        api::StatBucketReply::SP reply(new api::StatBucketReply(*_command, ost.str()));
+        auto reply = std::make_shared<api::StatBucketReply>(*_command, ost.str());
         sender.sendReply(reply);
     }
 }
diff --git a/storage/src/vespa/storage/distributor/operations/external/statbucketoperation.h b/storage/src/vespa/storage/distributor/operations/external/statbucketoperation.h
index 44215d2c68f..13850e642ad 100644
--- a/storage/src/vespa/storage/distributor/operations/external/statbucketoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/statbucketoperation.h
@@ -21,20 +21,18 @@ class StatBucketOperation : public Operation
 public:
     StatBucketOperation(DistributorBucketSpace &bucketSpace,
                         const std::shared_ptr<api::StatBucketCommand> & cmd);
-    ~StatBucketOperation();
+    ~StatBucketOperation() override;
 
-    const char* getName() const override { return "statBucket"; }
+    const char* getName() const noexcept override { return "statBucket"; }
     std::string getStatus() const override { return ""; }
     void onClose(DistributorStripeMessageSender& sender) override;
     void onStart(DistributorStripeMessageSender& sender) override;
     void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> & msg) override;
 private:
-    DistributorBucketSpace &_bucketSpace;
-
+    DistributorBucketSpace&                 _bucketSpace;
     std::shared_ptr<api::StatBucketCommand> _command;
-
-    std::map<uint64_t, uint16_t>    _sent;
-    std::map<uint16_t, std::string> _results;
+    std::map<uint64_t, uint16_t>            _sent;
+    std::map<uint16_t, std::string>         _results;
 };
 
 }
diff --git a/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.cpp
index 59f52465b93..2acd6068e1a 100644
--- a/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.cpp
@@ -22,13 +22,11 @@ using document::BucketSpace;
 
 namespace storage::distributor {
 
-
-
 TwoPhaseUpdateOperation::TwoPhaseUpdateOperation(
         const DistributorNodeContext& node_ctx,
         DistributorStripeOperationContext& op_ctx,
         const DocumentSelectionParser& parser,
-        DistributorBucketSpace &bucketSpace,
+        DistributorBucketSpace& bucketSpace,
         std::shared_ptr<api::UpdateCommand> msg,
         DistributorMetricSet& metrics,
         SequencingHandle sequencingHandle)
@@ -110,12 +108,13 @@ IntermediateMessageSender::IntermediateMessageSender(SentMessageMap& mm,
       callback(std::move(cb)),
       forward(fwd)
 { }
+
 IntermediateMessageSender::~IntermediateMessageSender() = default;
 
 }
 
 const char*
-TwoPhaseUpdateOperation::stateToString(SendState state)
+TwoPhaseUpdateOperation::stateToString(SendState state) noexcept
 {
     switch (state) {
     case SendState::NONE_SENT:          return "NONE_SENT";
diff --git a/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.h b/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.h
index 45dec86268f..7c1b6b3eed6 100644
--- a/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/twophaseupdateoperation.h
@@ -8,25 +8,20 @@
 #include <set>
 #include <optional>
 
-namespace document {
-class Document;
-}
-
-namespace storage {
+namespace document { class Document; }
 
-namespace api {
+namespace storage::api {
 class UpdateCommand;
 class UpdateReply;
 class CreateBucketReply;
 class ReturnCode;
 }
 
-class UpdateMetricSet;
-
-namespace distributor {
+namespace storage::distributor {
 
 class DistributorBucketSpace;
 class GetOperation;
+class UpdateMetricSet;
 
 /*
  * General functional outline:
@@ -59,7 +54,7 @@ public:
     TwoPhaseUpdateOperation(const DistributorNodeContext& node_ctx,
                             DistributorStripeOperationContext& op_ctx,
                             const DocumentSelectionParser& parser,
-                            DistributorBucketSpace &bucketSpace,
+                            DistributorBucketSpace& bucketSpace,
                             std::shared_ptr<api::UpdateCommand> msg,
                             DistributorMetricSet& metrics,
                             SequencingHandle sequencingHandle = SequencingHandle());
@@ -67,7 +62,7 @@ public:
 
     void onStart(DistributorStripeMessageSender& sender) override;
 
-    const char* getName() const override { return "twophaseupdate"; }
+    const char* getName() const noexcept override { return "twophaseupdate"; }
 
     std::string getStatus() const override { return ""; }
 
@@ -92,7 +87,7 @@ private:
     };
 
     void transitionTo(SendState newState);
-    static const char* stateToString(SendState);
+    static const char* stateToString(SendState) noexcept;
 
     void sendReply(DistributorStripeMessageSender&,
                    std::shared_ptr<api::UpdateReply>);
@@ -163,7 +158,3 @@ private:
 };
 
 }
-
-}
-
-
diff --git a/storage/src/vespa/storage/distributor/operations/external/updateoperation.cpp b/storage/src/vespa/storage/distributor/operations/external/updateoperation.cpp
index 5e3fe161f92..f3ce71b08d6 100644
--- a/storage/src/vespa/storage/distributor/operations/external/updateoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/updateoperation.cpp
@@ -41,6 +41,8 @@ UpdateOperation::UpdateOperation(const DistributorNodeContext& node_ctx,
 {
 }
 
+UpdateOperation::~UpdateOperation() = default;
+
 bool
 UpdateOperation::anyStorageNodesAvailable() const
 {
diff --git a/storage/src/vespa/storage/distributor/operations/external/updateoperation.h b/storage/src/vespa/storage/distributor/operations/external/updateoperation.h
index 7f3fef1260a..96fd878a324 100644
--- a/storage/src/vespa/storage/distributor/operations/external/updateoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/updateoperation.h
@@ -3,22 +3,17 @@
 
 #include <vespa/storage/distributor/persistencemessagetracker.h>
 
-namespace document {
-class Document;
-}
-
-namespace storage {
+namespace document { class Document; }
 
-namespace api {
+namespace storage::api {
 class UpdateCommand;
 class CreateBucketReply;
 }
 
-class UpdateMetricSet;
-
-namespace distributor {
+namespace storage::distributor {
 
 class DistributorBucketSpace;
+class UpdateMetricSet;
 
 class UpdateOperation : public Operation
 {
@@ -29,9 +24,10 @@ public:
                     const std::shared_ptr<api::UpdateCommand>& msg,
                     std::vector<BucketDatabase::Entry> entries,
                     UpdateMetricSet& metric);
+    ~UpdateOperation() override;
 
     void onStart(DistributorStripeMessageSender& sender) override;
-    const char* getName() const override { return "update"; };
+    const char* getName() const noexcept override { return "update"; };
     std::string getStatus() const override { return ""; };
     void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> & msg) override;
     void onClose(DistributorStripeMessageSender& sender) override;
@@ -77,5 +73,3 @@ private:
 };
 
 }
-
-}
diff --git a/storage/src/vespa/storage/distributor/operations/external/visitoroperation.cpp b/storage/src/vespa/storage/distributor/operations/external/visitoroperation.cpp
index 5abaad6ef9f..4d40e93477f 100644
--- a/storage/src/vespa/storage/distributor/operations/external/visitoroperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/external/visitoroperation.cpp
@@ -35,6 +35,8 @@ VisitorOperation::BucketInfo::print(vespalib::asciistream & out) const
     out << ")";
 }
 
+VisitorOperation::BucketInfo::~BucketInfo() = default;
+
 vespalib::string
 VisitorOperation::BucketInfo::toString() const
 {
diff --git a/storage/src/vespa/storage/distributor/operations/external/visitoroperation.h b/storage/src/vespa/storage/distributor/operations/external/visitoroperation.h
index ce10ea87c11..7f278c0383f 100644
--- a/storage/src/vespa/storage/distributor/operations/external/visitoroperation.h
+++ b/storage/src/vespa/storage/distributor/operations/external/visitoroperation.h
@@ -13,7 +13,6 @@
 
 namespace document { class Document; }
 
-namespace storage { struct VisitorMetricSet; }
 namespace storage::lib { class ClusterState; }
 
 namespace storage::distributor {
@@ -21,6 +20,7 @@ namespace storage::distributor {
 class DistributorBucketSpace;
 class DistributorNodeContext;
 class DistributorStripeOperationContext;
+struct VisitorMetricSet;
 
 class VisitorOperation  : public Operation
 {
@@ -37,7 +37,7 @@ public:
 
     VisitorOperation(const DistributorNodeContext& node_ctx,
                      DistributorStripeOperationContext& op_ctx,
-                     DistributorBucketSpace &bucketSpace,
+                     DistributorBucketSpace& bucketSpace,
                      const std::shared_ptr<api::CreateVisitorCommand>& msg,
                      const Config& config,
                      VisitorMetricSet& metrics);
@@ -47,7 +47,7 @@ public:
     void onClose(DistributorStripeMessageSender& sender) override;
     void onStart(DistributorStripeMessageSender& sender) override;
     void onReceive(DistributorStripeMessageSender& sender,
-                   const std::shared_ptr<api::StorageReply> & msg) override;
+                   const std::shared_ptr<api::StorageReply>& msg) override;
 
     // Only valid to call if is_read_for_write() == true
     void fail_with_bucket_already_locked(DistributorStripeMessageSender& sender);
@@ -55,7 +55,7 @@ public:
 
     [[nodiscard]] bool verify_command_and_expand_buckets(DistributorStripeMessageSender& sender);
 
-    const char* getName() const override { return "visit"; }
+    const char* getName() const noexcept override { return "visit"; }
     std::string getStatus() const override { return ""; }
 
     [[nodiscard]] bool has_sent_reply() const noexcept { return _sentReply; }
@@ -72,6 +72,7 @@ private:
         std::vector<uint16_t> triedNodes;
 
         BucketInfo() : done(false), activeNode(-1), failedCount(0), triedNodes() { }
+        ~BucketInfo();
 
         void print(vespalib::asciistream & out) const;
         vespalib::string toString() const;
diff --git a/storage/src/vespa/storage/distributor/operations/external/visitororder.h b/storage/src/vespa/storage/distributor/operations/external/visitororder.h
index 21dc8b1c6c6..90d6b2eaf07 100644
--- a/storage/src/vespa/storage/distributor/operations/external/visitororder.h
+++ b/storage/src/vespa/storage/distributor/operations/external/visitororder.h
@@ -7,9 +7,9 @@ namespace storage::distributor {
 
 struct VisitorOrder {
 
-    VisitorOrder() { }
+    VisitorOrder() = default;
 
-    bool operator()(const document::BucketId& a, const document::BucketId& b) {
+    bool operator()(const document::BucketId& a, const document::BucketId& b) noexcept {
         if (a == document::BucketId(INT_MAX) ||
             b == document::BucketId(0, 0)) {
             return false; // All before max, non before null
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/garbagecollectionoperation.h b/storage/src/vespa/storage/distributor/operations/idealstate/garbagecollectionoperation.h
index 25308b0fb4b..27dc519dcc2 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/garbagecollectionoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/garbagecollectionoperation.h
@@ -22,8 +22,8 @@ public:
 
     void onStart(DistributorStripeMessageSender& sender) override;
     void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> &) override;
-    const char* getName() const override { return "garbagecollection"; };
-    Type getType() const override { return GARBAGE_COLLECTION; }
+    const char* getName() const noexcept override { return "garbagecollection"; };
+    Type getType() const noexcept override { return GARBAGE_COLLECTION; }
     bool shouldBlockThisOperation(uint32_t, uint16_t, uint8_t) const override;
     bool is_two_phase() const noexcept {
         return ((_phase == Phase::ReadMetadataPhase) || (_phase == Phase::WriteRemovesPhase));
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/idealstateoperation.cpp b/storage/src/vespa/storage/distributor/operations/idealstate/idealstateoperation.cpp
index 744b24b593e..a69b7739e07 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/idealstateoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/idealstateoperation.cpp
@@ -28,8 +28,8 @@ IdealStateOperation::IdealStateOperation(const BucketAndNodes& bucketAndNodes)
     : _manager(nullptr),
       _bucketSpace(nullptr),
       _bucketAndNodes(bucketAndNodes),
-      _ok(true),
-      _priority(255)
+      _priority(255),
+      _ok(true)
 {
 }
 
@@ -111,7 +111,7 @@ IdealStateOperation::on_throttled()
 }
 
 uint32_t
-IdealStateOperation::memorySize() const
+IdealStateOperation::memorySize() const noexcept
 {
    return sizeof(*this) + _detailedReason.size();
 }
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/idealstateoperation.h b/storage/src/vespa/storage/distributor/operations/idealstate/idealstateoperation.h
index 7e62506b77f..6c52bdb738d 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/idealstateoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/idealstateoperation.h
@@ -55,23 +55,23 @@ public:
 
        @return Returns the target bucket.
     */
-    document::BucketId getBucketId() const { return _bucket.getBucketId(); }
+    document::BucketId getBucketId() const noexcept { return _bucket.getBucketId(); }
 
-    document::Bucket getBucket() const { return _bucket; }
+    document::Bucket getBucket() const noexcept { return _bucket; }
 
     /**
        Returns the target nodes
 
        @return the target nodes
     */
-    std::vector<uint16_t>& getNodes() { return _nodes; }
+    std::vector<uint16_t>& getNodes() noexcept { return _nodes; }
 
     /**
        Returns the target nodes
 
        @return the target nodes
     */
-    const std::vector<uint16_t>& getNodes() const { return _nodes; }
+    const std::vector<uint16_t>& getNodes() const noexcept { return _nodes; }
 
     /**
        Returns a string representation of this object.
@@ -105,14 +105,14 @@ class IdealStateOperation : public MaintenanceOperation
 public:
     static const uint32_t MAINTENANCE_MESSAGE_TYPES[];
 
-    typedef std::shared_ptr<IdealStateOperation> SP;
-    typedef std::unique_ptr<IdealStateOperation> UP;
-    typedef std::vector<SP> Vector;
-    typedef std::map<document::BucketId, SP> Map;
+    using SP = std::shared_ptr<IdealStateOperation>;
+    using UP = std::unique_ptr<IdealStateOperation>;
+    using Vector = std::vector<SP>;
+    using Map = std::map<document::BucketId, SP>;
 
     IdealStateOperation(const BucketAndNodes& bucketAndNodes);
 
-    virtual ~IdealStateOperation();
+    ~IdealStateOperation() override;
 
     void onClose(DistributorStripeMessageSender&) override {}
 
@@ -121,37 +121,37 @@ public:
 
        @return Returns the status of the operation.
     */
-    virtual bool ok() { return _ok; }
+    [[nodiscard]] bool ok() const noexcept { return _ok; }
 
     /**
        Returns the target nodes of the operation.
 
        @return The target nodes
     */
-    std::vector<uint16_t>& getNodes() { return _bucketAndNodes.getNodes(); }
+    std::vector<uint16_t>& getNodes() noexcept { return _bucketAndNodes.getNodes(); }
 
     /**
        Returns the target nodes of the operation.
 
        @return The target nodes
     */
-    const std::vector<uint16_t>& getNodes() const { return _bucketAndNodes.getNodes(); }
+    const std::vector<uint16_t>& getNodes() const noexcept { return _bucketAndNodes.getNodes(); }
 
     /**
        Returns the target bucket of the operation.
 
        @return The target bucket.
     */
-    document::BucketId getBucketId() const { return _bucketAndNodes.getBucketId(); }
+    document::BucketId getBucketId() const noexcept { return _bucketAndNodes.getBucketId(); }
 
-    document::Bucket getBucket() const { return _bucketAndNodes.getBucket(); }
+    document::Bucket getBucket() const noexcept { return _bucketAndNodes.getBucket(); }
 
     /**
        Returns the target of the operation.
 
        @return The target bucket and nodes
     */
-    const BucketAndNodes& getBucketAndNodes() const { return _bucketAndNodes; }
+    const BucketAndNodes& getBucketAndNodes() const noexcept { return _bucketAndNodes; }
 
     /**
        Called by the operation when it is finished. Must be called, otherwise the active
@@ -174,7 +174,7 @@ public:
     /**
        Returns the type of operation this is.
     */
-    virtual Type getType() const = 0;
+    virtual Type getType() const noexcept = 0;
 
     /**
        Set the priority we should send messages from this operation with.
@@ -192,7 +192,7 @@ public:
     /**
        Returns the priority we should send messages with.
     */
-    api::StorageMessage::Priority getPriority() { return _priority; }
+    api::StorageMessage::Priority getPriority() const noexcept { return _priority; }
 
     void setDetailedReason(const std::string& detailedReason) {
         _detailedReason = detailedReason;
@@ -205,7 +205,7 @@ public:
         return _detailedReason;
     }
 
-    uint32_t memorySize() const;
+    uint32_t memorySize() const noexcept;
 
     /**
      * Sets the various metadata for the given command that
@@ -224,13 +224,12 @@ protected:
     friend struct IdealStateManagerTest;
     friend class IdealStateManager;
 
-    IdealStateManager* _manager;
-    DistributorBucketSpace *_bucketSpace;
-    BucketAndNodes _bucketAndNodes;
-    std::string _detailedReason;
-
-    bool _ok;
+    IdealStateManager*            _manager;
+    DistributorBucketSpace*       _bucketSpace;
+    BucketAndNodes                _bucketAndNodes;
+    std::string                   _detailedReason;
     api::StorageMessage::Priority _priority;
+    bool                          _ok;
 
     /**
      * Checks if the given bucket is blocked by any pending messages to any
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/joinoperation.h b/storage/src/vespa/storage/distributor/operations/idealstate/joinoperation.h
index d8f77d89b8a..88fb3010654 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/joinoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/joinoperation.h
@@ -27,11 +27,11 @@ public:
     void onReceive(DistributorStripeMessageSender& sender,
                    const std::shared_ptr<api::StorageReply>&) override;
 
-    const char* getName() const override {
+    const char* getName() const noexcept override {
         return "join";
     }
 
-    Type getType() const override {
+    Type getType() const noexcept override {
         return JOIN_BUCKET;
     }
 
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/mergelimiter.h b/storage/src/vespa/storage/distributor/operations/idealstate/mergelimiter.h
index 6558aaf7f04..c139109ff0c 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/mergelimiter.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/mergelimiter.h
@@ -11,9 +11,9 @@ class MergeLimiter {
     uint16_t _maxNodes;
 
 public:
-    typedef std::vector<MergeMetaData> NodeArray;
+    using NodeArray = std::vector<MergeMetaData>;
 
-    MergeLimiter(uint16_t maxNodes);
+    explicit MergeLimiter(uint16_t maxNodes);
 
     void limitMergeToMaxNodes(NodeArray&);
 };
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/mergemetadata.cpp b/storage/src/vespa/storage/distributor/operations/idealstate/mergemetadata.cpp
index c5487511296..09fec1a88fd 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/mergemetadata.cpp
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/mergemetadata.cpp
@@ -3,14 +3,11 @@
 #include "mergemetadata.h"
 #include <vespa/vespalib/stllike/asciistream.h>
 
-namespace storage {
-namespace distributor {
+namespace storage::distributor {
 
 vespalib::asciistream& operator<<(vespalib::asciistream& out, const MergeMetaData& e)
 {
     return out << "MergeMetaData(" << e._nodeIndex << ")";
 }
 
-} // distributor
-} // storage
-
+} // storage::distributor
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/mergemetadata.h b/storage/src/vespa/storage/distributor/operations/idealstate/mergemetadata.h
index 446ab0407ca..07d1df4e81c 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/mergemetadata.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/mergemetadata.h
@@ -17,13 +17,13 @@ struct MergeMetaData {
     MergeMetaData(uint16_t nodeIndex, const BucketCopy& copy) noexcept
         : _nodeIndex(nodeIndex), _sourceOnly(false), _copy(&copy) {}
 
-    bool trusted() const {
+    [[nodiscard]] bool trusted() const noexcept {
         return _copy->trusted();
     }
-    uint32_t checksum() const {
+    [[nodiscard]] uint32_t checksum() const noexcept {
         return _copy->getChecksum();
     }
-    bool source_only() const noexcept { return _sourceOnly; }
+    [[nodiscard]] bool source_only() const noexcept { return _sourceOnly; }
 };
 
 vespalib::asciistream& operator<<(vespalib::asciistream& out, const MergeMetaData& e);
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/mergeoperation.h b/storage/src/vespa/storage/distributor/operations/idealstate/mergeoperation.h
index 014bae842fa..5416df3a43d 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/mergeoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/mergeoperation.h
@@ -10,6 +10,7 @@
 #include <vespa/storageapi/message/bucket.h>
 
 namespace storage::lib { class Distribution; }
+
 namespace storage::distributor {
 
 class MergeBucketMetricSet;
@@ -26,7 +27,6 @@ protected:
     MergeLimiter _limiter;
 
 public:
-    static const int LOAD = 10;
 
     MergeOperation(const BucketAndNodes& nodes, uint16_t maxNodes = 16)
         : IdealStateOperation(nodes),
@@ -34,13 +34,13 @@ public:
           _limiter(maxNodes)
     {}
 
-    ~MergeOperation();
+    ~MergeOperation() override;
 
     void onStart(DistributorStripeMessageSender& sender) override;
     void onReceive(DistributorStripeMessageSender& sender, const api::StorageReply::SP&) override;
-    const char* getName() const override { return "merge"; };
+    const char* getName() const noexcept override { return "merge"; };
     std::string getStatus() const override;
-    Type getType() const override { return MERGE_BUCKET; }
+    Type getType() const noexcept override { return MERGE_BUCKET; }
 
     /** Generates ordered list of nodes that should be included in the merge */
     static void generateSortedNodeList(
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/removebucketoperation.cpp b/storage/src/vespa/storage/distributor/operations/idealstate/removebucketoperation.cpp
index 25cae5b9979..e46ccebffba 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/removebucketoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/removebucketoperation.cpp
@@ -9,7 +9,9 @@
 
 LOG_SETUP(".distributor.operation.idealstate.remove");
 
-using namespace storage::distributor;
+namespace storage::distributor {
+
+RemoveBucketOperation::~RemoveBucketOperation() = default;
 
 bool
 RemoveBucketOperation::onStartInternal(DistributorStripeMessageSender& sender)
@@ -123,3 +125,4 @@ RemoveBucketOperation::shouldBlockThisOperation(uint32_t, uint16_t target_node,
     return false;
 }
 
+} // storage::distributor
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/removebucketoperation.h b/storage/src/vespa/storage/distributor/operations/idealstate/removebucketoperation.h
index 5e0922d5685..db6f5b997cc 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/removebucketoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/removebucketoperation.h
@@ -14,6 +14,7 @@ public:
     RemoveBucketOperation(const ClusterContext &cluster_context, const BucketAndNodes& nodes)
         : IdealStateOperation(nodes), _tracker(cluster_context)
     {}
+    ~RemoveBucketOperation() override;
 
     /**
        Sends messages, returns true if we are done (sent nothing).
@@ -28,8 +29,8 @@ public:
     bool onReceiveInternal(const std::shared_ptr<api::StorageReply> &);
 
     void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> &) override;
-    const char* getName() const override { return "remove"; };
-    Type getType() const override { return DELETE_BUCKET; }
+    const char* getName() const noexcept override { return "remove"; };
+    Type getType() const noexcept override { return DELETE_BUCKET; }
     bool shouldBlockThisOperation(uint32_t, uint16_t, uint8_t) const  override;
 protected:
     MessageTracker _tracker;
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/setbucketstateoperation.cpp b/storage/src/vespa/storage/distributor/operations/idealstate/setbucketstateoperation.cpp
index 76fb6829609..00906d22ea4 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/setbucketstateoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/setbucketstateoperation.cpp
@@ -10,7 +10,7 @@ LOG_SETUP(".distributor.operation.idealstate.setactive");
 
 namespace storage::distributor {
 
-SetBucketStateOperation::SetBucketStateOperation(const ClusterContext &cluster_ctx,
+SetBucketStateOperation::SetBucketStateOperation(const ClusterContext& cluster_ctx,
                                                  const BucketAndNodes& nodes,
                                                  const std::vector<uint16_t>& wantedActiveNodes)
     : IdealStateOperation(nodes),
@@ -37,7 +37,9 @@ bool
 SetBucketStateOperation::shouldBeActive(uint16_t node) const
 {
     for (uint32_t i=0, n=_wantedActiveNodes.size(); i<n; ++i) {
-        if (_wantedActiveNodes[i] == node) return true;
+        if (_wantedActiveNodes[i] == node) {
+            return true;
+        }
     }
     return false;
 }
@@ -73,8 +75,7 @@ void
 SetBucketStateOperation::onReceive(DistributorStripeMessageSender& sender,
                                    const std::shared_ptr<api::StorageReply>& reply)
 {
-    api::SetBucketStateReply& rep(
-            static_cast<api::SetBucketStateReply&>(*reply));
+    auto& rep = static_cast<api::SetBucketStateReply&>(*reply);
 
     const uint16_t node = _tracker.handleReply(rep);
     LOG(debug, "Got %s from node %u", reply->toString(true).c_str(), node);
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/setbucketstateoperation.h b/storage/src/vespa/storage/distributor/operations/idealstate/setbucketstateoperation.h
index 18160ba4d84..76c9c704653 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/setbucketstateoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/setbucketstateoperation.h
@@ -16,8 +16,8 @@ public:
 
     void onStart(DistributorStripeMessageSender&) override;
     void onReceive(DistributorStripeMessageSender&, const std::shared_ptr<api::StorageReply>&) override;
-    const char* getName() const override { return "setbucketstate"; }
-    Type getType() const override { return SET_BUCKET_STATE; }
+    const char* getName() const noexcept override { return "setbucketstate"; }
+    Type getType() const noexcept override { return SET_BUCKET_STATE; }
 protected:
     MessageTracker _tracker;
     std::vector<uint16_t> _wantedActiveNodes;
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/splitoperation.cpp b/storage/src/vespa/storage/distributor/operations/idealstate/splitoperation.cpp
index 6f3924535ef..97d86528ea0 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/splitoperation.cpp
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/splitoperation.cpp
@@ -11,7 +11,7 @@ LOG_SETUP(".distributor.operation.idealstate.split");
 
 using namespace storage::distributor;
 
-SplitOperation::SplitOperation(const ClusterContext &cluster_ctx, const BucketAndNodes& nodes,
+SplitOperation::SplitOperation(const ClusterContext& cluster_ctx, const BucketAndNodes& nodes,
                                uint32_t maxBits, uint32_t splitCount, uint32_t splitSize)
     : IdealStateOperation(nodes),
       _tracker(cluster_ctx),
@@ -19,6 +19,7 @@ SplitOperation::SplitOperation(const ClusterContext &cluster_ctx, const BucketAn
       _splitCount(splitCount),
       _splitSize(splitSize)
 {}
+
 SplitOperation::~SplitOperation() = default;
 
 void
diff --git a/storage/src/vespa/storage/distributor/operations/idealstate/splitoperation.h b/storage/src/vespa/storage/distributor/operations/idealstate/splitoperation.h
index 6a268155fc8..604b29e296c 100644
--- a/storage/src/vespa/storage/distributor/operations/idealstate/splitoperation.h
+++ b/storage/src/vespa/storage/distributor/operations/idealstate/splitoperation.h
@@ -12,14 +12,14 @@ public:
     SplitOperation(const ClusterContext& cluster_ctx,
                    const BucketAndNodes& nodes,
                    uint32_t maxBits, uint32_t splitCount, uint32_t splitSize);
-    SplitOperation(const SplitOperation &) = delete;
-    SplitOperation & operator = (const SplitOperation &) = delete;
+    SplitOperation(const SplitOperation&) = delete;
+    SplitOperation& operator=(const SplitOperation&) = delete;
     ~SplitOperation();
 
     void onStart(DistributorStripeMessageSender& sender) override;
-    void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply> &) override;
-    const char* getName() const override { return "split"; };
-    Type getType() const override { return SPLIT_BUCKET; }
+    void onReceive(DistributorStripeMessageSender& sender, const std::shared_ptr<api::StorageReply>&) override;
+    const char* getName() const noexcept override { return "split"; };
+    Type getType() const noexcept override { return SPLIT_BUCKET; }
     bool isBlocked(const DistributorStripeOperationContext&, const OperationSequencer&) const override;
     bool shouldBlockThisOperation(uint32_t, uint16_t, uint8_t) const override;
 protected:
diff --git a/storage/src/vespa/storage/distributor/operations/operation.h b/storage/src/vespa/storage/distributor/operations/operation.h
index fff0450cc04..e24aa976221 100644
--- a/storage/src/vespa/storage/distributor/operations/operation.h
+++ b/storage/src/vespa/storage/distributor/operations/operation.h
@@ -23,7 +23,7 @@ class OperationSequencer;
 class Operation
 {
 public:
-    typedef std::shared_ptr<Operation> SP;
+    using SP = std::shared_ptr<Operation>;
 
     Operation();
 
@@ -45,7 +45,7 @@ public:
         onReceive(sender, msg);
     }
 
-    virtual const char* getName() const = 0;
+    virtual const char* getName() const noexcept = 0;
 
     virtual std::string getStatus() const;
 
diff --git a/storage/src/vespa/storage/distributor/operationtargetresolver.cpp b/storage/src/vespa/storage/distributor/operationtargetresolver.cpp
index 6362e6fa2ed..62be9e47125 100644
--- a/storage/src/vespa/storage/distributor/operationtargetresolver.cpp
+++ b/storage/src/vespa/storage/distributor/operationtargetresolver.cpp
@@ -3,8 +3,7 @@
 #include "operationtargetresolver.h"
 #include <vespa/vespalib/stllike/asciistream.h>
 
-namespace storage {
-namespace distributor {
+namespace storage::distributor {
 
 void
 OperationTarget::print(vespalib::asciistream& out, const PrintProperties&) const {
@@ -13,5 +12,3 @@ OperationTarget::print(vespalib::asciistream& out, const PrintProperties&) const
 }
 
 }
-}
-
diff --git a/storage/src/vespa/storage/distributor/operationtargetresolver.h b/storage/src/vespa/storage/distributor/operationtargetresolver.h
index ea8c901fbeb..5e3c4a73f66 100644
--- a/storage/src/vespa/storage/distributor/operationtargetresolver.h
+++ b/storage/src/vespa/storage/distributor/operationtargetresolver.h
@@ -56,7 +56,7 @@ public:
 
 class OperationTargetResolver {
 public:
-    virtual ~OperationTargetResolver() {}
+    virtual ~OperationTargetResolver() = default;
 
     // Sadly all operations but put currently implement this by themselves.
     enum OperationType {
diff --git a/storage/src/vespa/storage/distributor/operationtargetresolverimpl.cpp b/storage/src/vespa/storage/distributor/operationtargetresolverimpl.cpp
index 86b469fe471..6a9d7e0e6da 100644
--- a/storage/src/vespa/storage/distributor/operationtargetresolverimpl.cpp
+++ b/storage/src/vespa/storage/distributor/operationtargetresolverimpl.cpp
@@ -82,11 +82,10 @@ BucketInstanceList::populate(const document::BucketId& specificId, const Distrib
 void
 BucketInstanceList::removeNodeDuplicates()
 {
-        // Normally few entries in list. Probably heaper to just go through entries
-        // to detect whether it pre exist rather than creating a set or similar.
+    // Normally few entries in list. Probably cheaper to just go through entries
+    // to detect whether it preexists rather than creating a set or similar.
     BucketInstanceList other;
-    for (uint32_t i=0; i<_instances.size(); ++i) {
-        BucketInstance& instance(_instances[i]);
+    for (const auto& instance : _instances) {
         if (!other.contains(instance._node)) {
             other.add(instance);
         }
@@ -97,7 +96,9 @@ BucketInstanceList::removeNodeDuplicates()
 void
 BucketInstanceList::limitToRedundancyCopies(uint16_t redundancy)
 {
-    while (_instances.size() > redundancy) _instances.pop_back();
+    while (_instances.size() > redundancy) {
+        _instances.pop_back();
+    }
 }
 
 document::BucketId
@@ -143,8 +144,7 @@ OperationTargetList
 BucketInstanceList::createTargets(document::BucketSpace bucketSpace)
 {
     OperationTargetList result;
-    for (uint32_t i=0; i<_instances.size(); ++i) {
-        BucketInstance& bi(_instances[i]);
+    for (const auto& bi : _instances) {
         result.push_back(OperationTarget(document::Bucket(bucketSpace, bi._bucket), bi._node, !bi._exist));
     }
     return result;
diff --git a/storage/src/vespa/storage/distributor/ownership_transfer_safe_time_point_calculator.cpp b/storage/src/vespa/storage/distributor/ownership_transfer_safe_time_point_calculator.cpp
index 6a03b2aa9bd..818c812ab4f 100644
--- a/storage/src/vespa/storage/distributor/ownership_transfer_safe_time_point_calculator.cpp
+++ b/storage/src/vespa/storage/distributor/ownership_transfer_safe_time_point_calculator.cpp
@@ -3,8 +3,7 @@
 #include "ownership_transfer_safe_time_point_calculator.h"
 #include <thread>
 
-namespace storage {
-namespace distributor {
+namespace storage::distributor {
 
 OwnershipTransferSafeTimePointCalculator::TimePoint
 OwnershipTransferSafeTimePointCalculator::safeTimePoint(TimePoint now) const
@@ -31,4 +30,3 @@ OwnershipTransferSafeTimePointCalculator::safeTimePoint(TimePoint now) const
 }
 
 }
-}
diff --git a/storage/src/vespa/storage/distributor/pendingclusterstate.cpp b/storage/src/vespa/storage/distributor/pendingclusterstate.cpp
index cf32d21eb82..c03b211d1aa 100644
--- a/storage/src/vespa/storage/distributor/pendingclusterstate.cpp
+++ b/storage/src/vespa/storage/distributor/pendingclusterstate.cpp
@@ -29,7 +29,7 @@ PendingClusterState::PendingClusterState(
         DistributorMessageSender& sender,
         const BucketSpaceStateMap& bucket_space_states,
         const std::shared_ptr<api::SetSystemStateCommand>& newStateCmd,
-        const OutdatedNodesMap &outdatedNodesMap,
+        const OutdatedNodesMap& outdatedNodesMap,
         api::Timestamp creationTimestamp)
     : _cmd(newStateCmd),
       _sentMessages(),
@@ -79,7 +79,7 @@ PendingClusterState::PendingClusterState(
 PendingClusterState::~PendingClusterState() = default;
 
 void
-PendingClusterState::initializeBucketSpaceTransitions(bool distributionChanged, const OutdatedNodesMap &outdatedNodesMap)
+PendingClusterState::initializeBucketSpaceTransitions(bool distributionChanged, const OutdatedNodesMap& outdatedNodesMap)
 {
     OutdatedNodes emptyOutdatedNodes;
     for (const auto &elem : _bucket_space_states) {
@@ -129,12 +129,6 @@ PendingClusterState::getOutdatedNodesMap() const
     return outdatedNodesMap;
 }
 
-uint16_t
-PendingClusterState::newStateStorageNodeCount() const
-{
-    return _newClusterStateBundle.getBaselineClusterState()->getNodeCount(lib::NodeType::STORAGE);
-}
-
 bool
 PendingClusterState::shouldRequestBucketInfo() const
 {
@@ -318,7 +312,7 @@ PendingClusterState::getSummary() const
                    (_clock.getTimeInMicros().getTime() - _creationTimestamp));
 }
 
-PendingBucketSpaceDbTransition &
+PendingBucketSpaceDbTransition&
 PendingClusterState::getPendingBucketSpaceDbTransition(document::BucketSpace bucketSpace)
 {
     auto transitionIter = _pendingTransitions.find(bucketSpace);
diff --git a/storage/src/vespa/storage/distributor/pendingclusterstate.h b/storage/src/vespa/storage/distributor/pendingclusterstate.h
index 1a2f8901b47..cbc526d75d3 100644
--- a/storage/src/vespa/storage/distributor/pendingclusterstate.h
+++ b/storage/src/vespa/storage/distributor/pendingclusterstate.h
@@ -49,7 +49,7 @@ public:
             DistributorMessageSender& sender,
             const BucketSpaceStateMap& bucket_space_states,
             const std::shared_ptr<api::SetSystemStateCommand>& newStateCmd,
-            const OutdatedNodesMap &outdatedNodesMap,
+            const OutdatedNodesMap& outdatedNodesMap,
             api::Timestamp creationTimestamp)
     {
         // Naked new due to private constructor
@@ -99,7 +99,7 @@ public:
      * Returns true if all the nodes we requested have replied to
      * the request bucket info commands.
      */
-    bool done() {
+    [[nodiscard]] bool done() const noexcept {
         return _sentMessages.empty() && _delayedRequests.empty();
     }
 
@@ -111,7 +111,7 @@ public:
         return (_cmd.get() != nullptr);
     }
 
-    std::shared_ptr<api::SetSystemStateCommand> getCommand() {
+    std::shared_ptr<api::SetSystemStateCommand> getCommand() const noexcept {
         return _cmd;
     }
 
@@ -128,7 +128,7 @@ public:
                 && _newClusterStateBundle.deferredActivation());
     }
 
-    void clearCommand() {
+    void clearCommand() noexcept {
         _cmd.reset();
     }
 
@@ -151,7 +151,7 @@ public:
     void merge_into_bucket_databases(StripeAccessGuard& guard);
 
     // Get pending transition for a specific bucket space. Only used by unit test.
-    PendingBucketSpaceDbTransition &getPendingBucketSpaceDbTransition(document::BucketSpace bucketSpace);
+    PendingBucketSpaceDbTransition& getPendingBucketSpaceDbTransition(document::BucketSpace bucketSpace);
 
     // May be a subset of the nodes in the cluster, depending on how many nodes were consulted
     // as part of the pending cluster state. Caller must take care to aggregate features.
@@ -202,16 +202,12 @@ private:
         }
     };
 
-    void initializeBucketSpaceTransitions(bool distributionChanged, const OutdatedNodesMap &outdatedNodesMap);
+    void initializeBucketSpaceTransitions(bool distributionChanged, const OutdatedNodesMap& outdatedNodesMap);
     void logConstructionInformation() const;
     void requestNode(BucketSpaceAndNode bucketSpaceAndNode);
     void requestNodes();
     void requestBucketInfoFromStorageNodesWithChangedState();
 
-    /**
-     * Number of nodes with node type 'storage' in _newClusterState.
-     */
-    uint16_t newStateStorageNodeCount() const;
     bool shouldRequestBucketInfo() const;
     bool clusterIsDown() const;
     bool iAmDown() const;
@@ -222,26 +218,30 @@ private:
     void update_reply_failure_statistics(const api::ReturnCode& result, const BucketSpaceAndNode& source);
     void update_node_supported_features_from_reply(uint16_t node, const api::RequestBucketInfoReply& reply);
 
-    std::shared_ptr<api::SetSystemStateCommand> _cmd;
+    using SentMessages       = std::map<uint64_t, BucketSpaceAndNode>;
+    using DelayedRequests    = std::deque<std::pair<framework::MilliSecTime, BucketSpaceAndNode>>;
+    using PendingTransitions = std::unordered_map<document::BucketSpace, std::unique_ptr<PendingBucketSpaceDbTransition>, document::BucketSpace::hash>;
+    using NodeFeatures       = vespalib::hash_map<uint16_t, NodeSupportedFeatures>;
 
-    std::map<uint64_t, BucketSpaceAndNode> _sentMessages;
-    std::vector<bool> _requestedNodes;
-    std::deque<std::pair<framework::MilliSecTime, BucketSpaceAndNode> > _delayedRequests;
+    std::shared_ptr<api::SetSystemStateCommand> _cmd;
 
-    lib::ClusterStateBundle _prevClusterStateBundle;
-    lib::ClusterStateBundle _newClusterStateBundle;
+    SentMessages               _sentMessages;
+    std::vector<bool>          _requestedNodes;
+    DelayedRequests            _delayedRequests;
 
-    const framework::Clock& _clock;
-    ClusterInformation::CSP _clusterInfo;
-    api::Timestamp _creationTimestamp;
+    lib::ClusterStateBundle    _prevClusterStateBundle;
+    lib::ClusterStateBundle    _newClusterStateBundle;
 
-    DistributorMessageSender& _sender;
+    const framework::Clock&    _clock;
+    ClusterInformation::CSP    _clusterInfo;
+    api::Timestamp             _creationTimestamp;
+    DistributorMessageSender&  _sender;
     const BucketSpaceStateMap& _bucket_space_states;
-    uint32_t _clusterStateVersion;
-    bool _isVersionedTransition;
-    bool _bucketOwnershipTransfer;
-    std::unordered_map<document::BucketSpace, std::unique_ptr<PendingBucketSpaceDbTransition>, document::BucketSpace::hash> _pendingTransitions;
-    vespalib::hash_map<uint16_t, NodeSupportedFeatures> _node_features;
+    uint32_t                   _clusterStateVersion;
+    bool                       _isVersionedTransition;
+    bool                       _bucketOwnershipTransfer;
+    PendingTransitions         _pendingTransitions;
+    NodeFeatures               _node_features;
 };
 
 }
diff --git a/storage/src/vespa/storage/distributor/pendingmessagetracker.h b/storage/src/vespa/storage/distributor/pendingmessagetracker.h
index 8f5f05d8a1a..b7fa666fe42 100644
--- a/storage/src/vespa/storage/distributor/pendingmessagetracker.h
+++ b/storage/src/vespa/storage/distributor/pendingmessagetracker.h
@@ -77,7 +77,7 @@ public:
      */
     using TimePoint = std::chrono::milliseconds;
 
-    explicit PendingMessageTracker(framework::ComponentRegister&, uint32_t stripe_index);
+    PendingMessageTracker(framework::ComponentRegister&, uint32_t stripe_index);
     ~PendingMessageTracker() override;
 
     void insert(const std::shared_ptr<api::StorageMessage>&);
@@ -111,8 +111,8 @@ public:
      * The vector might be smaller than a given node index. In that case, that storage
      * node has never had any pending messages.
      */
-    const NodeInfo& getNodeInfo() const { return _nodeInfo; }
-    NodeInfo& getNodeInfo() { return _nodeInfo; }
+    const NodeInfo& getNodeInfo() const noexcept { return _nodeInfo; }
+    NodeInfo& getNodeInfo() noexcept { return _nodeInfo; }
 
     /**
      * Clears all pending messages for the given node, and returns
diff --git a/storage/src/vespa/storage/distributor/persistence_operation_metric_set.cpp b/storage/src/vespa/storage/distributor/persistence_operation_metric_set.cpp
index 0e42a505567..944b4bafa0a 100644
--- a/storage/src/vespa/storage/distributor/persistence_operation_metric_set.cpp
+++ b/storage/src/vespa/storage/distributor/persistence_operation_metric_set.cpp
@@ -4,7 +4,7 @@
 #include <vespa/storageapi/messageapi/returncode.h>
 #include <vespa/metrics/summetric.hpp>
 
-namespace storage {
+namespace storage::distributor {
 
 using metrics::MetricSet;
 
@@ -107,5 +107,4 @@ PersistenceOperationMetricSet::updateFromResult(const api::ReturnCode& result)
     }
 }
 
-} // storage
-
+} // storage::distributor
diff --git a/storage/src/vespa/storage/distributor/persistence_operation_metric_set.h b/storage/src/vespa/storage/distributor/persistence_operation_metric_set.h
index d42e6fa308c..b818d1bdd9f 100644
--- a/storage/src/vespa/storage/distributor/persistence_operation_metric_set.h
+++ b/storage/src/vespa/storage/distributor/persistence_operation_metric_set.h
@@ -8,11 +8,9 @@
 #include <vespa/metrics/summetric.h>
 #include <mutex>
 
-namespace storage {
+namespace storage::api { class ReturnCode; }
 
-namespace api {
-class ReturnCode;
-}
+namespace storage::distributor {
 
 class PersistenceFailuresMetricSet : public metrics::MetricSet
 {
diff --git a/storage/src/vespa/storage/distributor/persistencemessagetracker.cpp b/storage/src/vespa/storage/distributor/persistencemessagetracker.cpp
index 45129f7be04..08b99cf89a8 100644
--- a/storage/src/vespa/storage/distributor/persistencemessagetracker.cpp
+++ b/storage/src/vespa/storage/distributor/persistencemessagetracker.cpp
@@ -4,7 +4,6 @@
 #include "distributor_bucket_space_repo.h"
 #include "distributor_bucket_space.h"
 #include <vespa/vdslib/distribution/distribution.h>
-#include <vespa/storage/common/vectorprinter.h>
 #include <vespa/storageapi/message/persistence.h>
 
 #include <vespa/log/log.h>
@@ -41,7 +40,7 @@ PersistenceMessageTrackerImpl::updateDB()
         _op_ctx.update_bucket_database(entry.first, entry.second);
     }
 
-    for (const auto & entry :  _remapBucketInfo){
+    for (const auto & entry : _remapBucketInfo){
         _op_ctx.update_bucket_database(entry.first, entry.second, DatabaseUpdate::CREATE_IF_NONEXISTING);
     }
 }
diff --git a/storage/src/vespa/storage/distributor/persistencemessagetracker.h b/storage/src/vespa/storage/distributor/persistencemessagetracker.h
index e65325cff20..ca330859259 100644
--- a/storage/src/vespa/storage/distributor/persistencemessagetracker.h
+++ b/storage/src/vespa/storage/distributor/persistencemessagetracker.h
@@ -43,7 +43,7 @@ public:
 
     void updateDB();
     void updateMetrics();
-    bool success() const { return _success; }
+    [[nodiscard]] bool success() const noexcept { return _success; }
     void fail(MessageSender& sender, const api::ReturnCode& result) override;
 
     /**
@@ -67,19 +67,19 @@ public:
 
 private:
     using MessageBatch = std::vector<uint64_t>;
-    std::vector<MessageBatch> _messageBatches;
 
-    PersistenceOperationMetricSet& _metric;
+    std::vector<MessageBatch>             _messageBatches;
+    PersistenceOperationMetricSet&        _metric;
     std::shared_ptr<api::BucketInfoReply> _reply;
-    DistributorStripeOperationContext& _op_ctx;
-    api::Timestamp _revertTimestamp;
-    std::vector<BucketNodePair> _revertNodes;
-    mbus::Trace _trace;
-    framework::MilliSecTimer _requestTimer;
-    uint32_t _n_persistence_replies_total;
-    uint32_t _n_successful_persistence_replies;
-    uint8_t _priority;
-    bool _success;
+    DistributorStripeOperationContext&    _op_ctx;
+    api::Timestamp                        _revertTimestamp;
+    std::vector<BucketNodePair>           _revertNodes;
+    mbus::Trace                           _trace;
+    framework::MilliSecTimer              _requestTimer;
+    uint32_t                              _n_persistence_replies_total;
+    uint32_t                              _n_successful_persistence_replies;
+    uint8_t                               _priority;
+    bool                                  _success;
 
     bool canSendReplyEarly() const;
     void addBucketInfoFromReply(uint16_t node, const api::BucketInfoReply& reply);
diff --git a/storage/src/vespa/storage/distributor/statechecker.h b/storage/src/vespa/storage/distributor/statechecker.h
index 11c83fdde07..348d90bc712 100644
--- a/storage/src/vespa/storage/distributor/statechecker.h
+++ b/storage/src/vespa/storage/distributor/statechecker.h
@@ -37,7 +37,7 @@ class NodeMaintenanceStatsTracker;
  */
 class StateChecker {
 public:
-    typedef std::shared_ptr<StateChecker> SP;
+    using SP = std::shared_ptr<StateChecker>;
 
     /**
      * Context object used when generating operations and metrics for a
@@ -49,48 +49,46 @@ public:
                 const DistributorStripeOperationContext& op_ctx_in,
                 const DistributorBucketSpace &distributorBucketSpace,
                 NodeMaintenanceStatsTracker&,
-                const document::Bucket &bucket_);
+                const document::Bucket& bucket_);
         ~Context();
-        Context(const Context &) = delete;
-        Context & operator =(const Context &) = delete;
+        Context(const Context&) = delete;
+        Context& operator=(const Context&) = delete;
 
 
         // Per bucket
-        document::Bucket   bucket;
-        document::BucketId siblingBucket;
-
-        BucketDatabase::Entry entry;
-        BucketDatabase::Entry siblingEntry;
+        document::Bucket                   bucket;
+        document::BucketId                 siblingBucket;
+        BucketDatabase::Entry              entry;
+        BucketDatabase::Entry              siblingEntry;
         std::vector<BucketDatabase::Entry> entries;
 
         // Common
-        const lib::ClusterState& systemState;
-        const lib::ClusterState* pending_cluster_state; // nullptr if no state is pending.
+        const lib::ClusterState&        systemState;
+        const lib::ClusterState*        pending_cluster_state; // nullptr if no state is pending.
         const DistributorConfiguration& distributorConfig;
-        const lib::Distribution& distribution;
-
-        BucketGcTimeCalculator gcTimeCalculator;
+        const lib::Distribution&        distribution;
+        BucketGcTimeCalculator          gcTimeCalculator;
 
         // Separate ideal state into ordered sequence and unordered set, as we
         // need to both know the actual order (activation prioritization etc) as
         // well as have the ability to quickly check if a node is in an ideal
         // location.
-        std::vector<uint16_t> idealState;
+        std::vector<uint16_t>        idealState;
         std::unordered_set<uint16_t> unorderedIdealState;
 
-        const DistributorNodeContext& node_ctx;
+        const DistributorNodeContext&            node_ctx;
         const DistributorStripeOperationContext& op_ctx;
-        const BucketDatabase& db;
-        NodeMaintenanceStatsTracker& stats;
-        const bool merges_inhibited_in_bucket_space;
+        const BucketDatabase&                    db;
+        NodeMaintenanceStatsTracker&             stats;
+        const bool                               merges_inhibited_in_bucket_space;
 
-        const BucketDatabase::Entry& getSiblingEntry() const {
+        const BucketDatabase::Entry& getSiblingEntry() const noexcept {
             return siblingEntry;
         }
 
-        document::Bucket getBucket() const { return bucket; }
-        document::BucketId getBucketId() const { return bucket.getBucketId(); }
-        document::BucketSpace getBucketSpace() const { return bucket.getBucketSpace(); }
+        document::Bucket getBucket() const noexcept { return bucket; }
+        document::BucketId getBucketId() const noexcept { return bucket.getBucketId(); }
+        document::BucketSpace getBucketSpace() const noexcept { return bucket.getBucketSpace(); }
 
         std::string toString() const;
     };
@@ -151,7 +149,7 @@ public:
     /**
      * Returns the name of this state checker.
      */
-    virtual const char* getName() const = 0;
+    virtual const char* getName() const noexcept = 0;
 };
 
 }
diff --git a/storage/src/vespa/storage/distributor/statecheckers.h b/storage/src/vespa/storage/distributor/statecheckers.h
index f998dbeacfd..c1579cb5eda 100644
--- a/storage/src/vespa/storage/distributor/statecheckers.h
+++ b/storage/src/vespa/storage/distributor/statecheckers.h
@@ -9,14 +9,14 @@ class SynchronizeAndMoveStateChecker : public StateChecker
 {
 public:
     Result check(Context& c) const override;
-    const char* getName() const override { return "SynchronizeAndMove"; }
+    const char* getName() const noexcept override { return "SynchronizeAndMove"; }
 };
 
 class DeleteExtraCopiesStateChecker : public StateChecker
 {
 public:
     Result check(Context& c) const override;
-    const char* getName() const override { return "DeleteExtraCopies"; }
+    const char* getName() const noexcept override { return "DeleteExtraCopies"; }
 
 private:
     static bool bucketHasNoData(const Context& c);
@@ -33,7 +33,7 @@ class JoinBucketsStateChecker : public StateChecker
 {
 public:
     Result check(Context& c) const override;
-    const char* getName() const override { return "JoinBuckets"; }
+    const char* getName() const noexcept override { return "JoinBuckets"; }
 private:
     static uint64_t getTotalUsedFileSize(const Context& c);
     static uint64_t getTotalMetaCount(const Context& c);
@@ -50,7 +50,7 @@ class SplitBucketStateChecker : public StateChecker
 {
 public:
     Result check(Context& c) const override;
-    const char* getName() const override { return "SplitBucket"; }
+    const char* getName() const noexcept override { return "SplitBucket"; }
 private:
     static Result generateMinimumBucketSplitOperation(Context& c);
     static Result generateMaxSizeExceededSplitOperation(Context& c);
@@ -63,14 +63,12 @@ class SplitInconsistentStateChecker : public StateChecker
 {
 public:
     Result check(Context& c) const override;
-    const char* getName() const override { return "SplitInconsistentBuckets"; }
+    const char* getName() const noexcept override { return "SplitInconsistentBuckets"; }
 
 private:
-    typedef std::pair<document::BucketId, uint16_t> BucketAndNode;
     static bool isLeastSplitBucket(const document::BucketId& bucket,const std::vector<BucketDatabase::Entry>& entries);
     static uint32_t getHighestUsedBits(const std::vector<BucketDatabase::Entry>& entries);
     static vespalib::string getReason(const document::BucketId& bucketId, const std::vector<BucketDatabase::Entry>& entries);
-    static bool isLeastSplit(Context& c, std::vector<BucketAndNode>& others);
 };
 
 class ActiveList;
@@ -80,14 +78,14 @@ class BucketStateStateChecker : public StateChecker
     static bool shouldSkipActivationDueToMaintenance(const ActiveList& activeList, const Context& c);
 public:
     Result check(Context& c) const override;
-    const char* getName() const override { return "SetBucketState"; }
+    const char* getName() const noexcept override { return "SetBucketState"; }
 };
 
 class GarbageCollectionStateChecker : public StateChecker
 {
 public:
     Result check(Context& c) const override;
-    const char* getName() const override { return "GarbageCollection"; }
+    const char* getName() const noexcept override { return "GarbageCollection"; }
 private:
     static bool garbage_collection_disabled(const Context& c) noexcept;
     static bool needs_garbage_collection(const Context& c, std::chrono::seconds time_since_epoch);
diff --git a/storage/src/vespa/storage/distributor/statusdelegator.h b/storage/src/vespa/storage/distributor/statusdelegator.h
index 0a4f3e63472..3001f135964 100644
--- a/storage/src/vespa/storage/distributor/statusdelegator.h
+++ b/storage/src/vespa/storage/distributor/statusdelegator.h
@@ -1,18 +1,16 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 #pragma once
 
-namespace storage {
-namespace distributor {
+namespace storage::distributor {
 
 struct DelegatedStatusRequest;
 
 class StatusDelegator
 {
 public:
-    virtual ~StatusDelegator() {}
+    virtual ~StatusDelegator() = default;
 
     virtual bool handleStatusRequest(const DelegatedStatusRequest& request) const = 0;
 };
 
-} // distributor
-} // storage
+} // storage::distributor
diff --git a/storage/src/vespa/storage/distributor/statusreporterdelegate.cpp b/storage/src/vespa/storage/distributor/statusreporterdelegate.cpp
index 41fc85baca5..a441ed9504c 100644
--- a/storage/src/vespa/storage/distributor/statusreporterdelegate.cpp
+++ b/storage/src/vespa/storage/distributor/statusreporterdelegate.cpp
@@ -15,6 +15,8 @@ StatusReporterDelegate::StatusReporterDelegate(
 {
 }
 
+StatusReporterDelegate::~StatusReporterDelegate() = default;
+
 vespalib::string
 StatusReporterDelegate::getReportContentType(const framework::HttpUrlPath& path) const
 {
diff --git a/storage/src/vespa/storage/distributor/statusreporterdelegate.h b/storage/src/vespa/storage/distributor/statusreporterdelegate.h
index 0acf9b16edb..fb13812beb0 100644
--- a/storage/src/vespa/storage/distributor/statusreporterdelegate.h
+++ b/storage/src/vespa/storage/distributor/statusreporterdelegate.h
@@ -5,9 +5,7 @@
 #include "statusdelegator.h"
 #include <vespa/storageframework/generic/component/component.h>
 
-
-namespace storage {
-namespace distributor {
+namespace storage::distributor {
 
 class StatusReporterDelegate
     : public framework::StatusReporter
@@ -19,11 +17,11 @@ public:
     StatusReporterDelegate(framework::ComponentRegister& compReg,
                            const StatusDelegator& delegator,
                            const framework::StatusReporter& target);
+    ~StatusReporterDelegate() override;
 
     void registerStatusPage();
     vespalib::string getReportContentType(const framework::HttpUrlPath&) const override;
     bool reportStatus(std::ostream&, const framework::HttpUrlPath&) const override;
 };
 
-} // distributor
-} // storage
+} // storage::distributor
diff --git a/storage/src/vespa/storage/distributor/stripe_bucket_db_updater.h b/storage/src/vespa/storage/distributor/stripe_bucket_db_updater.h
index 7a34ed03a3c..b31ffe53451 100644
--- a/storage/src/vespa/storage/distributor/stripe_bucket_db_updater.h
+++ b/storage/src/vespa/storage/distributor/stripe_bucket_db_updater.h
@@ -4,12 +4,12 @@
 #include "bucketlistmerger.h"
 #include "distributor_stripe_component.h"
 #include "distributormessagesender.h"
-#include "messageguard.h"
 #include "operation_routing_snapshot.h"
 #include "outdated_nodes_map.h"
 #include "pendingclusterstate.h"
 #include "potential_data_loss_report.h"
 #include <vespa/document/bucket/bucket.h>
+#include <vespa/storage/common/message_guard.h>
 #include <vespa/storage/common/storagelink.h>
 #include <vespa/storageapi/message/bucket.h>
 #include <vespa/storageapi/messageapi/messagehandler.h>
diff --git a/storage/src/vespa/storage/distributor/throttlingoperationstarter.h b/storage/src/vespa/storage/distributor/throttlingoperationstarter.h
index 00d1237b2f7..a0613c60fa4 100644
--- a/storage/src/vespa/storage/distributor/throttlingoperationstarter.h
+++ b/storage/src/vespa/storage/distributor/throttlingoperationstarter.h
@@ -30,7 +30,7 @@ class ThrottlingOperationStarter : public OperationStarter, public PendingWindow
         void onClose(DistributorStripeMessageSender& sender) override {
             _operation->onClose(sender);
         }
-        const char* getName() const override {
+        const char* getName() const noexcept override {
             return _operation->getName();
         }
         std::string getStatus() const override {
diff --git a/storage/src/vespa/storage/distributor/top_level_bucket_db_updater.h b/storage/src/vespa/storage/distributor/top_level_bucket_db_updater.h
index d8e49d5c383..921ebf65338 100644
--- a/storage/src/vespa/storage/distributor/top_level_bucket_db_updater.h
+++ b/storage/src/vespa/storage/distributor/top_level_bucket_db_updater.h
@@ -4,11 +4,11 @@
 #include "bucketlistmerger.h"
 #include "distributor_component.h"
 #include "distributormessagesender.h"
-#include "messageguard.h"
 #include "operation_routing_snapshot.h"
 #include "outdated_nodes_map.h"
 #include "pendingclusterstate.h"
 #include <vespa/document/bucket/bucket.h>
+#include <vespa/storage/common/message_guard.h>
 #include <vespa/storage/common/storagelink.h>
 #include <vespa/storageapi/message/bucket.h>
 #include <vespa/storageapi/messageapi/messagehandler.h>
diff --git a/storage/src/vespa/storage/distributor/update_metric_set.cpp b/storage/src/vespa/storage/distributor/update_metric_set.cpp
index 82f55d3e819..fafce3dae5a 100644
--- a/storage/src/vespa/storage/distributor/update_metric_set.cpp
+++ b/storage/src/vespa/storage/distributor/update_metric_set.cpp
@@ -2,7 +2,7 @@
 
 #include "update_metric_set.h"
 
-namespace storage {
+namespace storage::distributor {
 
 using metrics::MetricSet;
 
diff --git a/storage/src/vespa/storage/distributor/update_metric_set.h b/storage/src/vespa/storage/distributor/update_metric_set.h
index 4171a8c32da..ad39f8e93cc 100644
--- a/storage/src/vespa/storage/distributor/update_metric_set.h
+++ b/storage/src/vespa/storage/distributor/update_metric_set.h
@@ -3,7 +3,7 @@
 
 #include "persistence_operation_metric_set.h"
 
-namespace storage {
+namespace storage::distributor {
 
 class UpdateMetricSet : public PersistenceOperationMetricSet {
 public:
diff --git a/storage/src/vespa/storage/distributor/visitormetricsset.cpp b/storage/src/vespa/storage/distributor/visitormetricsset.cpp
index c94dc025fa1..cbc2f0e25d3 100644
--- a/storage/src/vespa/storage/distributor/visitormetricsset.cpp
+++ b/storage/src/vespa/storage/distributor/visitormetricsset.cpp
@@ -2,7 +2,7 @@
 
 #include "visitormetricsset.h"
 
-namespace storage {
+namespace storage::distributor {
 
 using metrics::MetricSet;
 
diff --git a/storage/src/vespa/storage/distributor/visitormetricsset.h b/storage/src/vespa/storage/distributor/visitormetricsset.h
index 35e03faf279..7751e0805f2 100644
--- a/storage/src/vespa/storage/distributor/visitormetricsset.h
+++ b/storage/src/vespa/storage/distributor/visitormetricsset.h
@@ -3,7 +3,7 @@
 
 #include "persistence_operation_metric_set.h"
 
-namespace storage {
+namespace storage::distributor {
 
 struct VisitorMetricSet : public PersistenceOperationMetricSet {
     metrics::LongAverageMetric buckets_per_visitor;
@@ -11,11 +11,10 @@ struct VisitorMetricSet : public PersistenceOperationMetricSet {
     metrics::LongAverageMetric bytes_per_visitor;
 
     VisitorMetricSet(MetricSet* owner = nullptr);
-    ~VisitorMetricSet();
+    ~VisitorMetricSet() override;
 
     MetricSet * clone(std::vector<Metric::UP>& ownerList, CopyType copyType,
                       MetricSet* owner, bool includeUnused) const override;
 };
 
-} // storage
-
+} // storage::distributor
diff --git a/storage/src/vespa/storage/storageserver/mergethrottler.cpp b/storage/src/vespa/storage/storageserver/mergethrottler.cpp
index 681d97299fa..2dea5681b85 100644
--- a/storage/src/vespa/storage/storageserver/mergethrottler.cpp
+++ b/storage/src/vespa/storage/storageserver/mergethrottler.cpp
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "mergethrottler.h"
+#include <vespa/storageapi/message/state.h>
 #include <vespa/storage/common/nodestateupdater.h>
 #include <vespa/storage/common/dummy_mbus_messages.h>
 #include <vespa/storage/persistence/messages.h>
diff --git a/storage/src/vespa/storage/storageserver/mergethrottler.h b/storage/src/vespa/storage/storageserver/mergethrottler.h
index e501e0edd39..76a25c0cf22 100644
--- a/storage/src/vespa/storage/storageserver/mergethrottler.h
+++ b/storage/src/vespa/storage/storageserver/mergethrottler.h
@@ -8,9 +8,9 @@
 #pragma once
 
 #include <vespa/storage/config/config-stor-server.h>
+#include <vespa/storage/common/message_guard.h>
 #include <vespa/storage/common/storagelink.h>
 #include <vespa/storage/common/storagecomponent.h>
-#include <vespa/storage/distributor/messageguard.h>
 #include <vespa/storageframework/generic/status/htmlstatusreporter.h>
 #include <vespa/storageapi/message/bucket.h>
 #include <vespa/document/bucket/bucket.h>
diff --git a/storage/src/vespa/storageapi/defs.h b/storage/src/vespa/storageapi/defs.h
index 9ee9fdf2218..bf802a20a5c 100644
--- a/storage/src/vespa/storageapi/defs.h
+++ b/storage/src/vespa/storageapi/defs.h
@@ -10,9 +10,9 @@
 
 namespace storage:: api {
 
-typedef uint64_t Timestamp;
-typedef uint32_t VisitorId;
+using Timestamp = uint64_t;
+using VisitorId = uint32_t;
 
-const Timestamp MAX_TIMESTAMP = (Timestamp)-1ll;
+constexpr Timestamp MAX_TIMESTAMP = (Timestamp)-1LL;
 
 }
diff --git a/storage/src/vespa/storageapi/message/stat.h b/storage/src/vespa/storageapi/message/stat.h
index 0797ae43799..875580ca064 100644
--- a/storage/src/vespa/storageapi/message/stat.h
+++ b/storage/src/vespa/storageapi/message/stat.h
@@ -58,15 +58,15 @@ class GetBucketListReply : public BucketReply {
 public:
     struct BucketInfo {
         document::BucketId _bucket;
-        vespalib::string _bucketInformation;
+        vespalib::string   _bucketInformation;
 
         BucketInfo(const document::BucketId& id,
-                   vespalib::stringref bucketInformation)
+                   vespalib::stringref bucketInformation) noexcept
             : _bucket(id),
               _bucketInformation(bucketInformation)
         {}
 
-        bool operator==(const BucketInfo& other) const {
+        bool operator==(const BucketInfo& other) const noexcept {
             return (_bucket == other._bucket
                     && _bucketInformation == other._bucketInformation);
         }