Improve handling of changed alloc config.

3 files changed, 49 insertions, 0 deletions

diff --git a/searchlib/src/tests/attribute/compaction/attribute_compaction_test.cpp b/searchlib/src/tests/attribute/compaction/attribute_compaction_test.cpp
index dde6b14121d..36a697eaa12 100644
--- a/searchlib/src/tests/attribute/compaction/attribute_compaction_test.cpp
+++ b/searchlib/src/tests/attribute/compaction/attribute_compaction_test.cpp
@@ -226,4 +226,24 @@ TEST_F("Compaction is not executed when free lists are used",
     EXPECT_EQUAL(1001u, afterSpace.dead());
 }
 
+TEST_F("Compaction is peformed when compaction strategy is changed to enable compaction",
+       Fixture(compactAddressSpaceAttributeConfig(false)))
+{
+    populate_and_hammer(f, true);
+    AddressSpace after1 = f.getMultiValueAddressSpaceUsage("after1");
+    // 100 * 1000 dead arrays due to new values for docids
+    // 1 reserved array accounted as dead
+    EXPECT_EQUAL(100001u, after1.dead());
+    f._v->update_config(compactAddressSpaceAttributeConfig(true));
+    auto old_dead = after1.dead();
+    AddressSpace after2 = f.getMultiValueAddressSpaceUsage("after2");
+    while (after2.dead() < old_dead) {
+        old_dead = after2.dead();
+        f._v->commit(); // new commit might trigger further compaction
+        after2 = f.getMultiValueAddressSpaceUsage("after2");
+    }
+    // DEAD_ARRAYS_SLACK in multi value mapping is is 64k
+    EXPECT_GREATER(65536u, after2.dead());
+}
+
 TEST_MAIN() { TEST_RUN_ALL(); }
diff --git a/searchlib/src/vespa/searchlib/attribute/attributevector.cpp b/searchlib/src/vespa/searchlib/attribute/attributevector.cpp
index 2168bbe4276..d2574bd32a2 100644
--- a/searchlib/src/vespa/searchlib/attribute/attributevector.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/attributevector.cpp
@@ -21,6 +21,7 @@
 #include <vespa/vespalib/util/exceptions.h>
 #include <vespa/searchlib/util/logutil.h>
 #include <vespa/searchcommon/attribute/attribute_utils.h>
+#include <thread>
 
 #include <vespa/log/log.h>
 LOG_SETUP(".searchlib.attribute.attributevector");
@@ -769,6 +770,31 @@ AttributeVector::logEnumStoreEvent(const char *reason, const char *stage)
     EV_STATE(eventName.c_str(), jstr.toString().data());
 }
 
+void
+AttributeVector::drain_hold(uint64_t hold_limit)
+{
+    incGeneration();
+    for (int retry = 0; ; ++retry) {
+        removeAllOldGenerations();
+        updateStat(true);
+        if (_status.getOnHold() <= hold_limit) {
+            return;
+        }
+        std::this_thread::sleep_for(retry < 20 ? 20ms : 100ms);
+    }
+}
+
+void
+AttributeVector::update_config(const Config& cfg)
+{
+    commit(true);
+    drain_hold(1024 * 1024); // Wait until 1MiB or less on hold
+    _config.setGrowStrategy(cfg.getGrowStrategy());
+    _config.setCompactionStrategy(cfg.getCompactionStrategy());
+    commit(); // might trigger compaction if compaction strategy changed
+    drain_hold(1024 * 1024); // Wait until 1MiB or less on hold
+}
+
 template bool AttributeVector::append<StringChangeData>(ChangeVectorT< ChangeTemplate<StringChangeData> > &changes, uint32_t , const StringChangeData &, int32_t, bool);
 template bool AttributeVector::update<StringChangeData>(ChangeVectorT< ChangeTemplate<StringChangeData> > &changes, uint32_t , const StringChangeData &);
 template bool AttributeVector::remove<StringChangeData>(ChangeVectorT< ChangeTemplate<StringChangeData> > &changes, uint32_t , const StringChangeData &, int32_t);
diff --git a/searchlib/src/vespa/searchlib/attribute/attributevector.h b/searchlib/src/vespa/searchlib/attribute/attributevector.h
index 4fc6589850e..f308ee8d024 100644
--- a/searchlib/src/vespa/searchlib/attribute/attributevector.h
+++ b/searchlib/src/vespa/searchlib/attribute/attributevector.h
@@ -393,6 +393,7 @@ public:
     /** Return the fixed length of the attribute. If 0 then you must inquire each document. */
     size_t getFixedWidth() const override { return _config.basicType().fixedSize(); }
     const Config &getConfig() const { return _config; }
+    void update_config(const Config& cfg);
     BasicType getInternalBasicType() const { return _config.basicType(); }
     CollectionType getInternalCollectionType() const { return _config.collectionType(); }
     const BaseName & getBaseFileName() const { return _baseFileName; }
@@ -667,6 +668,8 @@ public:
     static bool isEnumerated(const vespalib::GenericHeader &header);
 
     virtual vespalib::MemoryUsage getChangeVectorMemoryUsage() const;
+
+    void drain_hold(uint64_t hold_limit);
 };
 
 }