Merge pull request #25848 from vespa-engine/toregge/add-document-db-prepare-reconfig

Add proton::DocumentDB::prepare_reconfig

17 files changed, 111 insertions, 56 deletions

diff --git a/searchcore/src/tests/proton/documentdb/document_subdbs/document_subdbs_test.cpp b/searchcore/src/tests/proton/documentdb/document_subdbs/document_subdbs_test.cpp
index b1fda6e0efb..307695c4f4b 100644
--- a/searchcore/src/tests/proton/documentdb/document_subdbs/document_subdbs_test.cpp
+++ b/searchcore/src/tests/proton/documentdb/document_subdbs/document_subdbs_test.cpp
@@ -19,6 +19,7 @@
 #include <vespa/searchcore/proton/server/bootstrapconfig.h>
 #include <vespa/searchcore/proton/server/document_subdb_explorer.h>
 #include <vespa/searchcore/proton/server/document_subdb_initializer.h>
+#include <vespa/searchcore/proton/server/document_subdb_reconfig.h>
 #include <vespa/searchcore/proton/server/emptysearchview.h>
 #include <vespa/searchcore/proton/server/fast_access_document_retriever.h>
 #include <vespa/searchcore/proton/server/i_document_subdb_owner.h>
@@ -377,8 +378,11 @@ struct FixtureBase
         cmpResult.documenttypesChanged = true;
         cmpResult.documentTypeRepoChanged = true;
         MyDocumentDBReferenceResolver resolver;
+        ReconfigParams reconfig_params(cmpResult);
+        auto prepared_reconfig = _subDb.prepare_reconfig(*newCfg->_cfg, *_snapshot->_cfg, reconfig_params);
         auto tasks = _subDb.applyConfig(*newCfg->_cfg, *_snapshot->_cfg,
-                                        serialNum, ReconfigParams(cmpResult), resolver);
+                                        serialNum, reconfig_params, resolver, *prepared_reconfig);
+        prepared_reconfig.reset();
         _snapshot = std::move(newCfg);
         if (!tasks.empty()) {
             ReprocessingRunner runner;
diff --git a/searchcore/src/vespa/searchcore/proton/server/document_db_reconfig.cpp b/searchcore/src/vespa/searchcore/proton/server/document_db_reconfig.cpp
index bd7b14483ad..903c9d0a899 100644
--- a/searchcore/src/vespa/searchcore/proton/server/document_db_reconfig.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/document_db_reconfig.cpp
@@ -12,5 +12,7 @@ DocumentDBReconfig::DocumentDBReconfig(std::unique_ptr<const DocumentSubDBReconf
 {
 }
 
+DocumentDBReconfig::~DocumentDBReconfig() = default;
+
 }
 
diff --git a/searchcore/src/vespa/searchcore/proton/server/document_db_reconfig.h b/searchcore/src/vespa/searchcore/proton/server/document_db_reconfig.h
index c1f768511c8..21ea117f7e9 100644
--- a/searchcore/src/vespa/searchcore/proton/server/document_db_reconfig.h
+++ b/searchcore/src/vespa/searchcore/proton/server/document_db_reconfig.h
@@ -26,6 +26,7 @@ private:
 public:
     DocumentDBReconfig(std::unique_ptr<const DocumentSubDBReconfig> ready_reconfig_in,
                        std::unique_ptr<const DocumentSubDBReconfig> not_ready_reconfig_in);
+    ~DocumentDBReconfig();
 
     const DocumentSubDBReconfig& ready_reconfig() const { return *_ready_reconfig; }
     const DocumentSubDBReconfig& not_ready_reconfig() const { return *_not_ready_reconfig; }
diff --git a/searchcore/src/vespa/searchcore/proton/server/document_subdb_reconfig.cpp b/searchcore/src/vespa/searchcore/proton/server/document_subdb_reconfig.cpp
index 3692fa07c06..2fd222338e7 100644
--- a/searchcore/src/vespa/searchcore/proton/server/document_subdb_reconfig.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/document_subdb_reconfig.cpp
@@ -10,5 +10,7 @@ DocumentSubDBReconfig::DocumentSubDBReconfig(std::shared_ptr<Matchers> matchers_
 {
 }
 
+DocumentSubDBReconfig::~DocumentSubDBReconfig() = default;
+
 }
 
diff --git a/searchcore/src/vespa/searchcore/proton/server/document_subdb_reconfig.h b/searchcore/src/vespa/searchcore/proton/server/document_subdb_reconfig.h
index ed9faeee6fc..89129a6b0d0 100644
--- a/searchcore/src/vespa/searchcore/proton/server/document_subdb_reconfig.h
+++ b/searchcore/src/vespa/searchcore/proton/server/document_subdb_reconfig.h
@@ -17,6 +17,7 @@ private:
 
 public:
     DocumentSubDBReconfig(std::shared_ptr<Matchers> matchers_in);
+    ~DocumentSubDBReconfig();
 
     void set_matchers(std::shared_ptr<Matchers> value) {
         _new_matchers = std::move(value);
diff --git a/searchcore/src/vespa/searchcore/proton/server/documentdb.cpp b/searchcore/src/vespa/searchcore/proton/server/documentdb.cpp
index 6241af3fcf7..110b0324dc3 100644
--- a/searchcore/src/vespa/searchcore/proton/server/documentdb.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/documentdb.cpp
@@ -3,6 +3,7 @@
 #include "documentdb.h"
 #include "bootstrapconfig.h"
 #include "combiningfeedview.h"
+#include "document_db_reconfig.h"
 #include "document_meta_store_read_guards.h"
 #include "document_subdb_collection_explorer.h"
 #include "documentdbconfigscout.h"
@@ -347,34 +348,18 @@ DocumentDB::initFinish(DocumentDBConfig::SP configSnapshot)
     startTransactionLogReplay();
 }
 
-
-void
-DocumentDB::newConfigSnapshot(DocumentDBConfig::SP snapshot)
+std::unique_ptr<DocumentDBReconfig>
+DocumentDB::prepare_reconfig(const DocumentDBConfig& new_config_snapshot)
 {
-    // Called by executor thread
-    _pendingConfigSnapshot.set(std::move(snapshot));
-    {
-        lock_guard guard(_configMutex);
-        if ( ! _activeConfigSnapshot) {
-            LOG(debug,
-                "DocumentDB(%s): Ignoring new available config snapshot. "
-                "The document database does not have"
-                " an active config snapshot yet", _docTypeName.toString().c_str());
-            return;
-        }
-        if (!_state.getAllowReconfig()) {
-            LOG(warning,
-                "DocumentDB(%s): Ignoring new available config snapshot. "
-                "The document database is not allowed to"
-                " reconfigure yet. Wait until replay is done before"
-                " you try to reconfigure again", _docTypeName.toString().c_str());
-            return;
-        }
+    auto active_config_snapshot = getActiveConfig();
+    auto cmpres = active_config_snapshot->compare(new_config_snapshot);
+    if (_state.getState() == DDBState::State::APPLY_LIVE_CONFIG) {
+        cmpres.importedFieldsChanged = true;
     }
-    masterExecute([this] () { performReconfig(_pendingConfigSnapshot.get()); } );
+    const ReconfigParams reconfig_params(cmpres);
+    return _subDBs.prepare_reconfig(new_config_snapshot, *active_config_snapshot, reconfig_params);
 }
 
-
 void
 DocumentDB::enterReprocessState()
 {
@@ -411,10 +396,10 @@ DocumentDB::enterOnlineState()
 }
 
 void
-DocumentDB::performReconfig(DocumentDBConfig::SP configSnapshot)
+DocumentDB::performReconfig(DocumentDBConfig::SP configSnapshot, std::unique_ptr<DocumentDBReconfig> prepared_reconfig)
 {
     // Called by executor thread
-    applyConfig(std::move(configSnapshot), getCurrentSerialNumber());
+    applyConfig(std::move(configSnapshot), getCurrentSerialNumber(), std::move(prepared_reconfig));
     if (_state.getState() == DDBState::State::APPLY_LIVE_CONFIG) {
         enterReprocessState();
     }
@@ -423,7 +408,7 @@ DocumentDB::performReconfig(DocumentDBConfig::SP configSnapshot)
 
 void
 DocumentDB::applySubDBConfig(const DocumentDBConfig &newConfigSnapshot,
-                             SerialNum serialNum, const ReconfigParams &params)
+                             SerialNum serialNum, const ReconfigParams &params, const DocumentDBReconfig& prepared_reconfig)
 {
     auto registry = _owner.getDocumentDBReferenceRegistry();
     auto oldRepo = _activeConfigSnapshot->getDocumentTypeRepoSP();
@@ -434,11 +419,11 @@ DocumentDB::applySubDBConfig(const DocumentDBConfig &newConfigSnapshot,
     assert(newDocType != nullptr);
     DocumentDBReferenceResolver resolver(*registry, *newDocType, newConfigSnapshot.getImportedFieldsConfig(), *oldDocType,
                                          _refCount, _writeService.attributeFieldWriter(), _state.getAllowReconfig());
-    _subDBs.applyConfig(newConfigSnapshot, *_activeConfigSnapshot, serialNum, params, resolver);
+    _subDBs.applyConfig(newConfigSnapshot, *_activeConfigSnapshot, serialNum, params, resolver, prepared_reconfig);
 }
 
 void
-DocumentDB::applyConfig(DocumentDBConfig::SP configSnapshot, SerialNum serialNum)
+DocumentDB::applyConfig(DocumentDBConfig::SP configSnapshot, SerialNum serialNum, std::unique_ptr<const DocumentDBReconfig> prepared_reconfig)
 {
     // Always called by executor thread:
     // Called by performReconfig() by executor thread during normal
@@ -456,9 +441,6 @@ DocumentDB::applyConfig(DocumentDBConfig::SP configSnapshot, SerialNum serialNum
     {
         lock_guard guard(_configMutex);
         assert(_activeConfigSnapshot.get());
-        if (_state.getState() >= DDBState::State::ONLINE) {
-            configSnapshot = DocumentDBConfig::makeDelayedAttributeAspectConfig(configSnapshot, *_activeConfigSnapshot);
-        }
         if (configSnapshot->getDelayedAttributeAspects()) {
             _state.setConfigState(DDBState::ConfigState::NEED_RESTART);
             LOG(info, "DocumentDB(%s): Delaying attribute aspect changes: need restart",
@@ -501,7 +483,7 @@ DocumentDB::applyConfig(DocumentDBConfig::SP configSnapshot, SerialNum serialNum
                                   _writeServiceConfig.defaultTaskLimit(),
                                   _writeServiceConfig.defaultTaskLimit());
     if (params.shouldSubDbsChange()) {
-        applySubDBConfig(*configSnapshot, serialNum, params);
+        applySubDBConfig(*configSnapshot, serialNum, params, *prepared_reconfig);
         if (serialNum < _feedHandler->get_replay_end_serial_num()) {
             // Not last entry in tls.  Reprocessing should already be done.
             _subDBs.getReprocessingRunner().reset();
@@ -808,7 +790,14 @@ DocumentDB::setIndexSchema(const DocumentDBConfig &configSnapshot, SerialNum ser
 void
 DocumentDB::reconfigure(DocumentDBConfig::SP snapshot)
 {
-    masterExecute([this, snapshot]() mutable { newConfigSnapshot(std::move(snapshot)); });
+    // Called by proton executor thread (c.f. ProtonConfigurer::configureDocumentDB)
+    _pendingConfigSnapshot.set(snapshot);
+    auto active_snapshot = getActiveConfig();
+    assert(active_snapshot);
+    assert(_state.getAllowReconfig());
+    snapshot = DocumentDBConfig::makeDelayedAttributeAspectConfig(snapshot, *active_snapshot);
+    auto prepared_reconfig = prepare_reconfig(*snapshot);
+    masterExecute([this, snapshot, prepared_reconfig = std::move(prepared_reconfig)]() mutable { performReconfig(snapshot, std::move(prepared_reconfig)); });
     // Wait for config to be applied, or for document db close
     std::unique_lock<std::mutex> guard(_configMutex);
     while ((_activeConfigSnapshotGeneration < snapshot->getGeneration()) && !_state.getClosed()) {
@@ -845,7 +834,12 @@ DocumentDB::enterApplyLiveConfigState()
         lock_guard guard(_configMutex);
         (void) _state.enterApplyLiveConfigState();
     }
-    masterExecute([this]() { performReconfig(_pendingConfigSnapshot.get()); });
+    auto new_config_snapshot = _pendingConfigSnapshot.get();
+    auto prepared_reconfig = prepare_reconfig(*new_config_snapshot);
+    masterExecute([this, new_config_snapshot, prepared_reconfig = std::move(prepared_reconfig)]() mutable
+                  {
+                      performReconfig(std::move(new_config_snapshot), std::move(prepared_reconfig));
+                  });
 }
 
 
@@ -902,7 +896,8 @@ DocumentDB::replayConfig(search::SerialNum serialNum)
     configSnapshot = DocumentDBConfigScout::scout(configSnapshot, *_pendingConfigSnapshot.get());
     // Ignore configs that are not relevant during replay of transaction log
     configSnapshot = DocumentDBConfig::makeReplayConfig(configSnapshot);
-    applyConfig(configSnapshot, serialNum);
+    auto prepared_reconfig = prepare_reconfig(*configSnapshot);
+    applyConfig(configSnapshot, serialNum, std::move(prepared_reconfig));
     LOG(info, "DocumentDB(%s): Replayed config with serialNum=%" PRIu64,
               _docTypeName.toString().c_str(), serialNum);
 }
diff --git a/searchcore/src/vespa/searchcore/proton/server/documentdb.h b/searchcore/src/vespa/searchcore/proton/server/documentdb.h
index 09e54f518f7..2b3e6ef4052 100644
--- a/searchcore/src/vespa/searchcore/proton/server/documentdb.h
+++ b/searchcore/src/vespa/searchcore/proton/server/documentdb.h
@@ -53,6 +53,7 @@ namespace storage::spi { struct BucketExecutor; }
 
 namespace proton {
 class AttributeConfigInspector;
+class DocumentDBReconfig;
 class ExecutorThreadingServiceStats;
 class IDocumentDBOwner;
 class ISharedThreadingService;
@@ -149,12 +150,13 @@ private:
     void internalInit();
     void initManagers();
     void initFinish(DocumentDBConfigSP configSnapshot);
-    void performReconfig(DocumentDBConfigSP configSnapshot);
+    void performReconfig(DocumentDBConfigSP configSnapshot, std::unique_ptr<DocumentDBReconfig> prepared_reconfig);
     void closeSubDBs();
 
     void applySubDBConfig(const DocumentDBConfig &newConfigSnapshot,
-                          SerialNum serialNum, const ReconfigParams &params);
-    void applyConfig(DocumentDBConfigSP configSnapshot, SerialNum serialNum);
+                          SerialNum serialNum, const ReconfigParams &params,
+                          const DocumentDBReconfig& prepared_reconfig);
+    void applyConfig(DocumentDBConfigSP configSnapshot, SerialNum serialNum, std::unique_ptr<const DocumentDBReconfig> prepared_reconfig);
 
     /**
      * Save initial config if we don't have any saved config snapshots.
@@ -380,7 +382,7 @@ public:
     bool getDelayedConfig() const { return _state.getDelayedConfig(); }
     void replayConfig(SerialNum serialNum) override;
     const DocTypeName & getDocTypeName() const { return _docTypeName; }
-    void newConfigSnapshot(DocumentDBConfigSP snapshot);
+    std::unique_ptr<DocumentDBReconfig> prepare_reconfig(const DocumentDBConfig& new_config_snapshot);
     void reconfigure(DocumentDBConfigSP snapshot) override;
     int64_t getActiveGeneration() const;
     /*
diff --git a/searchcore/src/vespa/searchcore/proton/server/documentsubdbcollection.cpp b/searchcore/src/vespa/searchcore/proton/server/documentsubdbcollection.cpp
index 855a40780cb..573683c21a9 100644
--- a/searchcore/src/vespa/searchcore/proton/server/documentsubdbcollection.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/documentsubdbcollection.cpp
@@ -2,7 +2,9 @@
 
 #include "documentsubdbcollection.h"
 #include "combiningfeedview.h"
+#include "document_db_reconfig.h"
 #include "document_subdb_collection_initializer.h"
+#include "document_subdb_reconfig.h"
 #include "i_document_subdb_owner.h"
 #include "maintenancecontroller.h"
 #include "searchabledocsubdb.h"
@@ -248,20 +250,31 @@ DocumentSubDBCollection::pruneRemovedFields(SerialNum serialNum)
     }
 }
 
+std::unique_ptr<DocumentDBReconfig>
+DocumentSubDBCollection::prepare_reconfig(const DocumentDBConfig& new_config_snapshot, const DocumentDBConfig& old_config_snapshot, const ReconfigParams& reconfig_params)
+{
+    auto ready_reconfig = getReadySubDB()->prepare_reconfig(new_config_snapshot, old_config_snapshot, reconfig_params);
+    auto not_ready_reconfig = getNotReadySubDB()->prepare_reconfig(new_config_snapshot, old_config_snapshot, reconfig_params);
+    return std::make_unique<DocumentDBReconfig>(std::move(ready_reconfig), std::move(not_ready_reconfig));
+}
 
 void
 DocumentSubDBCollection::applyConfig(const DocumentDBConfig &newConfigSnapshot,
                                      const DocumentDBConfig &oldConfigSnapshot,
                                      SerialNum serialNum,
                                      const ReconfigParams &params,
-                                     IDocumentDBReferenceResolver &resolver)
+                                     IDocumentDBReferenceResolver &resolver,
+                                     const DocumentDBReconfig& prepared_reconfig)
 {
     _reprocessingRunner.reset();
-    for (auto subDb : _subDBs) {
-        IReprocessingTask::List tasks;
-        tasks = subDb->applyConfig(newConfigSnapshot, oldConfigSnapshot, serialNum, params, resolver);
-        _reprocessingRunner.addTasks(tasks);
-    }
+    auto tasks = getReadySubDB()->applyConfig(newConfigSnapshot, oldConfigSnapshot, serialNum, params, resolver, prepared_reconfig.ready_reconfig());
+    _reprocessingRunner.addTasks(tasks);
+    tasks = getNotReadySubDB()->applyConfig(newConfigSnapshot, oldConfigSnapshot, serialNum, params, resolver, prepared_reconfig.not_ready_reconfig());
+    _reprocessingRunner.addTasks(tasks);
+    auto removed_reconfig = getRemSubDB()->prepare_reconfig(newConfigSnapshot, oldConfigSnapshot, params);
+    tasks = getRemSubDB()->applyConfig(newConfigSnapshot, oldConfigSnapshot, serialNum, params, resolver, *removed_reconfig);
+    removed_reconfig.reset();
+    _reprocessingRunner.addTasks(tasks);
 }
 
 IFeedView::SP
diff --git a/searchcore/src/vespa/searchcore/proton/server/documentsubdbcollection.h b/searchcore/src/vespa/searchcore/proton/server/documentsubdbcollection.h
index a5ab1b5971c..21f36c7ca3e 100644
--- a/searchcore/src/vespa/searchcore/proton/server/documentsubdbcollection.h
+++ b/searchcore/src/vespa/searchcore/proton/server/documentsubdbcollection.h
@@ -31,6 +31,7 @@ namespace proton {
 
 class DocTypeName;
 class DocumentDBConfig;
+class DocumentDBReconfig;
 class FeedHandler;
 class HwInfo;
 class IDocumentRetriever;
@@ -136,8 +137,9 @@ public:
 
     void pruneRemovedFields(SerialNum serialNum);
 
+    std::unique_ptr<DocumentDBReconfig> prepare_reconfig(const DocumentDBConfig& new_config_snapshot, const DocumentDBConfig& old_config_snapshot, const ReconfigParams& reconfig_params);
     void applyConfig(const DocumentDBConfig &newConfigSnapshot, const DocumentDBConfig &oldConfigSnapshot,
-                     SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver);
+                     SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver, const DocumentDBReconfig& prepared_reconfig);
 
     IFeedViewSP getFeedView();
     IFlushTargetList getFlushTargets();
diff --git a/searchcore/src/vespa/searchcore/proton/server/fast_access_doc_subdb.cpp b/searchcore/src/vespa/searchcore/proton/server/fast_access_doc_subdb.cpp
index 48ce0f37c28..0727dd493eb 100644
--- a/searchcore/src/vespa/searchcore/proton/server/fast_access_doc_subdb.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/fast_access_doc_subdb.cpp
@@ -241,7 +241,7 @@ FastAccessDocSubDB::initViews(const DocumentDBConfig &configSnapshot)
 
 IReprocessingTask::List
 FastAccessDocSubDB::applyConfig(const DocumentDBConfig &newConfigSnapshot, const DocumentDBConfig &oldConfigSnapshot,
-                                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &)
+                                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &, const DocumentSubDBReconfig&)
 {
     AllocStrategy alloc_strategy = newConfigSnapshot.get_alloc_config().make_alloc_strategy(_subDbType);
     reconfigure(newConfigSnapshot.getStoreConfig(), alloc_strategy);
diff --git a/searchcore/src/vespa/searchcore/proton/server/fast_access_doc_subdb.h b/searchcore/src/vespa/searchcore/proton/server/fast_access_doc_subdb.h
index 2d00a2a412c..0ace6bab33f 100644
--- a/searchcore/src/vespa/searchcore/proton/server/fast_access_doc_subdb.h
+++ b/searchcore/src/vespa/searchcore/proton/server/fast_access_doc_subdb.h
@@ -111,7 +111,7 @@ public:
 
     IReprocessingTask::List
     applyConfig(const DocumentDBConfig &newConfigSnapshot, const DocumentDBConfig &oldConfigSnapshot,
-                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver) override;
+                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver, const DocumentSubDBReconfig& prepared_reconfig) override;
 
     proton::IAttributeManager::SP getAttributeManager() const override;
     IDocumentRetriever::UP getDocumentRetriever() override;
diff --git a/searchcore/src/vespa/searchcore/proton/server/idocumentsubdb.h b/searchcore/src/vespa/searchcore/proton/server/idocumentsubdb.h
index c6410073c09..99804fe253f 100644
--- a/searchcore/src/vespa/searchcore/proton/server/idocumentsubdb.h
+++ b/searchcore/src/vespa/searchcore/proton/server/idocumentsubdb.h
@@ -25,6 +25,7 @@ namespace proton {
 namespace matching { class SessionManager; }
 
 class DocumentDBConfig;
+class DocumentSubDBReconfig;
 class DocumentSubDbInitializer;
 class DocumentSubDbInitializerResult;
 class FeedHandler;
@@ -78,9 +79,11 @@ public:
     virtual void setup(const DocumentSubDbInitializerResult &initResult) = 0;
     virtual void initViews(const DocumentDBConfig &configSnapshot) = 0;
 
+    virtual std::unique_ptr<const DocumentSubDBReconfig>
+    prepare_reconfig(const DocumentDBConfig& new_config_snapshot, const DocumentDBConfig& old_config_snapshot, const ReconfigParams& reconfig_params) = 0;
     virtual IReprocessingTask::List
     applyConfig(const DocumentDBConfig &newConfigSnapshot, const DocumentDBConfig &oldConfigSnapshot,
-                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver) = 0;
+                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver, const DocumentSubDBReconfig& prepared_reconfig) = 0;
     virtual void setBucketStateCalculator(const std::shared_ptr<IBucketStateCalculator> &calc, OnDone) = 0;
 
     virtual std::shared_ptr<ISearchHandler> getSearchView() const = 0;
diff --git a/searchcore/src/vespa/searchcore/proton/server/searchabledocsubdb.cpp b/searchcore/src/vespa/searchcore/proton/server/searchabledocsubdb.cpp
index 506b541bbd3..4b3c1901b4e 100644
--- a/searchcore/src/vespa/searchcore/proton/server/searchabledocsubdb.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/searchabledocsubdb.cpp
@@ -3,6 +3,7 @@
 #include "searchabledocsubdb.h"
 #include "fast_access_document_retriever.h"
 #include "document_subdb_initializer.h"
+#include "document_subdb_reconfig.h"
 #include "reconfig_params.h"
 #include "i_document_subdb_owner.h"
 #include <vespa/searchcore/proton/attribute/attribute_writer.h>
@@ -132,10 +133,20 @@ reconfigureMatchingMetrics(const RankProfilesConfig &cfg)
     }
 }
 
+std::unique_ptr<const DocumentSubDBReconfig>
+SearchableDocSubDB::prepare_reconfig(const DocumentDBConfig& new_config_snapshot, const DocumentDBConfig& old_config_snapshot, const ReconfigParams& reconfig_params)
+{
+    (void) new_config_snapshot;
+    (void) old_config_snapshot;
+    (void) reconfig_params;
+    return std::make_unique<const DocumentSubDBReconfig>(std::shared_ptr<Matchers>());
+}
+
 IReprocessingTask::List
 SearchableDocSubDB::applyConfig(const DocumentDBConfig &newConfigSnapshot, const DocumentDBConfig &oldConfigSnapshot,
-                                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver)
+                                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver, const DocumentSubDBReconfig& prepared_reconfig)
 {
+    (void) prepared_reconfig;
     AllocStrategy alloc_strategy = newConfigSnapshot.get_alloc_config().make_alloc_strategy(_subDbType);
     StoreOnlyDocSubDB::reconfigure(newConfigSnapshot.getStoreConfig(), alloc_strategy);
     IReprocessingTask::List tasks;
diff --git a/searchcore/src/vespa/searchcore/proton/server/searchabledocsubdb.h b/searchcore/src/vespa/searchcore/proton/server/searchabledocsubdb.h
index 806d1191072..e3906f84f13 100644
--- a/searchcore/src/vespa/searchcore/proton/server/searchabledocsubdb.h
+++ b/searchcore/src/vespa/searchcore/proton/server/searchabledocsubdb.h
@@ -102,9 +102,11 @@ public:
     void setup(const DocumentSubDbInitializerResult &initResult) override;
     void initViews(const DocumentDBConfig &configSnapshot) override;
 
+    std::unique_ptr<const DocumentSubDBReconfig>
+    prepare_reconfig(const DocumentDBConfig& new_config_snapshot, const DocumentDBConfig& old_config_snapshot, const ReconfigParams& reconfig_params) override;
     IReprocessingTask::List
     applyConfig(const DocumentDBConfig &newConfigSnapshot, const DocumentDBConfig &oldConfigSnapshot,
-                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver) override;
+                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver, const DocumentSubDBReconfig& prepared_reconfig) override;
     void setBucketStateCalculator(const std::shared_ptr<IBucketStateCalculator> &calc, OnDone onDone) override;
 
     void clearViews() override;
diff --git a/searchcore/src/vespa/searchcore/proton/server/storeonlydocsubdb.cpp b/searchcore/src/vespa/searchcore/proton/server/storeonlydocsubdb.cpp
index a5d679f87af..22aeeec4ef6 100644
--- a/searchcore/src/vespa/searchcore/proton/server/storeonlydocsubdb.cpp
+++ b/searchcore/src/vespa/searchcore/proton/server/storeonlydocsubdb.cpp
@@ -4,6 +4,7 @@
 #include "docstorevalidator.h"
 #include "document_subdb_initializer.h"
 #include "document_subdb_initializer_result.h"
+#include "document_subdb_reconfig.h"
 #include "emptysearchview.h"
 #include "i_document_subdb_owner.h"
 #include "minimal_document_retriever.h"
@@ -404,14 +405,24 @@ StoreOnlyDocSubDB::getSubDbName() const {
     return vespalib::make_string("%s.%s", _owner.getName().c_str(), _subName.c_str());
 }
 
+std::unique_ptr<const DocumentSubDBReconfig>
+StoreOnlyDocSubDB::prepare_reconfig(const DocumentDBConfig& new_config_snapshot, const DocumentDBConfig& old_config_snapshot, const ReconfigParams& reconfig_params)
+{
+    (void) new_config_snapshot;
+    (void) old_config_snapshot;
+    (void) reconfig_params;
+    return std::make_unique<const DocumentSubDBReconfig>(std::shared_ptr<Matchers>());
+}
+
 IReprocessingTask::List
 StoreOnlyDocSubDB::applyConfig(const DocumentDBConfig &newConfigSnapshot, const DocumentDBConfig &oldConfigSnapshot,
-                               SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver)
+                               SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver, const DocumentSubDBReconfig& prepared_reconfig)
 {
     (void) oldConfigSnapshot;
     (void) serialNum;
     (void) params;
     (void) resolver;
+    (void) prepared_reconfig;
     assert(_writeService.master().isCurrentThread());
     AllocStrategy alloc_strategy = newConfigSnapshot.get_alloc_config().make_alloc_strategy(_subDbType);
     reconfigure(newConfigSnapshot.getStoreConfig(), alloc_strategy);
diff --git a/searchcore/src/vespa/searchcore/proton/server/storeonlydocsubdb.h b/searchcore/src/vespa/searchcore/proton/server/storeonlydocsubdb.h
index 5a8db23e345..f547ced67c7 100644
--- a/searchcore/src/vespa/searchcore/proton/server/storeonlydocsubdb.h
+++ b/searchcore/src/vespa/searchcore/proton/server/storeonlydocsubdb.h
@@ -200,9 +200,11 @@ public:
 
     void validateDocStore(FeedHandler & feedHandler, SerialNum serialNum) const override;
 
+    std::unique_ptr<const DocumentSubDBReconfig>
+    prepare_reconfig(const DocumentDBConfig& new_config_snapshot, const DocumentDBConfig& old_config_snapshot, const ReconfigParams& reconfig_params) override;
     IReprocessingTask::List
     applyConfig(const DocumentDBConfig &newConfigSnapshot, const DocumentDBConfig &oldConfigSnapshot,
-                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver) override;
+                SerialNum serialNum, const ReconfigParams &params, IDocumentDBReferenceResolver &resolver, const DocumentSubDBReconfig &prepared_reconfig) override;
     void setBucketStateCalculator(const std::shared_ptr<IBucketStateCalculator> &calc, OnDone onDone) override;
 
     ISearchHandler::SP getSearchView() const override { return _iSearchView.get(); }
diff --git a/searchcore/src/vespa/searchcore/proton/test/dummy_document_sub_db.h b/searchcore/src/vespa/searchcore/proton/test/dummy_document_sub_db.h
index 24504c92cb2..85315158c3c 100644
--- a/searchcore/src/vespa/searchcore/proton/test/dummy_document_sub_db.h
+++ b/searchcore/src/vespa/searchcore/proton/test/dummy_document_sub_db.h
@@ -7,6 +7,7 @@
 #include <vespa/searchcorespi/index/iindexmanager.h>
 #include <vespa/searchcore/proton/documentmetastore/documentmetastorecontext.h>
 #include <vespa/searchcore/proton/server/document_subdb_initializer.h>
+#include <vespa/searchcore/proton/server/document_subdb_reconfig.h>
 #include <vespa/searchcore/proton/server/isummaryadapter.h>
 #include <vespa/searchcore/proton/index/i_index_writer.h>
 #include <vespa/searchcore/proton/server/ifeedview.h>
@@ -51,8 +52,11 @@ struct DummyDocumentSubDb : public IDocumentSubDB
     }
     void setup(const DocumentSubDbInitializerResult &) override {}
     void initViews(const DocumentDBConfig &) override {}
+    std::unique_ptr<const DocumentSubDBReconfig> prepare_reconfig(const DocumentDBConfig&, const DocumentDBConfig&, const ReconfigParams&) override {
+        return std::make_unique<const DocumentSubDBReconfig>(std::shared_ptr<Matchers>());
+    }
     IReprocessingTask::List applyConfig(const DocumentDBConfig &, const DocumentDBConfig &,
-                                        SerialNum, const ReconfigParams &, IDocumentDBReferenceResolver &) override
+                                        SerialNum, const ReconfigParams &, IDocumentDBReferenceResolver &, const DocumentSubDBReconfig&) override
     {
         return IReprocessingTask::List();
     }