Merge pull request #13081 from vespa-engine/balder/remove-flush

Remove flush from provider interface.

14 files changed, 10 insertions, 192 deletions

diff --git a/persistence/src/vespa/persistence/conformancetest/conformancetest.cpp b/persistence/src/vespa/persistence/conformancetest/conformancetest.cpp
index 5c8b5b029d2..298e29cbecb 100644
--- a/persistence/src/vespa/persistence/conformancetest/conformancetest.cpp
+++ b/persistence/src/vespa/persistence/conformancetest/conformancetest.cpp
@@ -300,8 +300,6 @@ feedDocs(PersistenceProvider& spi,
         EXPECT_TRUE(!result.hasError());
         docs.push_back(DocAndTimestamp(doc, Timestamp(1000 + i)));
     }
-    spi.flush(bucket, context);
-    EXPECT_EQ(Result(), Result(spi.flush(bucket, context)));
     return docs;
 }
 
@@ -354,8 +352,6 @@ TEST_F(ConformanceTest, testBasics)
             Result(),
             Result(spi->remove(bucket, Timestamp(3), doc1->getId(), context)));
 
-    EXPECT_EQ(Result(), Result(spi->flush(bucket, context)));
-
     // Iterate first without removes, then with.
     for (int iterPass = 0; iterPass < 2; ++iterPass) {
         bool includeRemoves = (iterPass == 1);
@@ -441,11 +437,8 @@ TEST_F(ConformanceTest, testListBuckets)
     spi->createBucket(bucket3, context);
 
     spi->put(bucket1, Timestamp(1), doc1, context);
-    spi->flush(bucket1, context);
     spi->put(bucket2, Timestamp(2), doc2, context);
-    spi->flush(bucket2, context);
     spi->put(bucket3, Timestamp(3), doc3, context);
-    spi->flush(bucket3, context);
 
     {
         BucketIdListResult result = spi->listBuckets(makeBucketSpace(), PartitionId(1));
@@ -482,7 +475,6 @@ TEST_F(ConformanceTest, testBucketInfo)
     spi->put(bucket, Timestamp(2), doc2, context);
 
     const BucketInfo info1 = spi->getBucketInfo(bucket).getBucketInfo();
-    spi->flush(bucket, context);
 
     {
         EXPECT_EQ(1, (int)info1.getDocumentCount());
@@ -492,7 +484,6 @@ TEST_F(ConformanceTest, testBucketInfo)
     spi->put(bucket, Timestamp(3), doc1, context);
 
     const BucketInfo info2 = spi->getBucketInfo(bucket).getBucketInfo();
-    spi->flush(bucket, context);
 
     {
         EXPECT_EQ(2, (int)info2.getDocumentCount());
@@ -503,7 +494,6 @@ TEST_F(ConformanceTest, testBucketInfo)
     spi->put(bucket, Timestamp(4), doc1, context);
 
     const BucketInfo info3 = spi->getBucketInfo(bucket).getBucketInfo();
-    spi->flush(bucket, context);
 
     {
         EXPECT_EQ(2, (int)info3.getDocumentCount());
@@ -514,7 +504,6 @@ TEST_F(ConformanceTest, testBucketInfo)
     spi->remove(bucket, Timestamp(5), doc1->getId(), context);
 
     const BucketInfo info4 = spi->getBucketInfo(bucket).getBucketInfo();
-    spi->flush(bucket, context);
 
     {
         EXPECT_EQ(1, (int)info4.getDocumentCount());
@@ -544,7 +533,6 @@ TEST_F(ConformanceTest, testOrderIndependentBucketInfo)
     {
         spi->put(bucket, Timestamp(2), doc1, context);
         spi->put(bucket, Timestamp(3), doc2, context);
-        spi->flush(bucket, context);
         const BucketInfo info(spi->getBucketInfo(bucket).getBucketInfo());
 
         checksumOrdered = info.getChecksum();
@@ -563,7 +551,6 @@ TEST_F(ConformanceTest, testOrderIndependentBucketInfo)
         // Swap order of puts
         spi->put(bucket, Timestamp(3), doc2, context);
         spi->put(bucket, Timestamp(2), doc1, context);
-        spi->flush(bucket, context);
         const BucketInfo info(spi->getBucketInfo(bucket).getBucketInfo());
 
         checksumUnordered = info.getChecksum();
@@ -589,7 +576,6 @@ TEST_F(ConformanceTest, testPut)
 
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
 
         EXPECT_EQ(1, (int)info.getDocumentCount());
         EXPECT_TRUE(info.getEntryCount() >= info.getDocumentCount());
@@ -615,7 +601,6 @@ TEST_F(ConformanceTest, testPutNewDocumentVersion)
     Result result = spi->put(bucket, Timestamp(3), doc1, context);
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
 
         EXPECT_EQ(1, (int)info.getDocumentCount());
         EXPECT_TRUE(info.getEntryCount() >= info.getDocumentCount());
@@ -627,7 +612,6 @@ TEST_F(ConformanceTest, testPutNewDocumentVersion)
     result = spi->put(bucket, Timestamp(4), doc2, context);
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
 
         EXPECT_EQ(1, (int)info.getDocumentCount());
         EXPECT_TRUE(info.getEntryCount() >= info.getDocumentCount());
@@ -666,7 +650,6 @@ TEST_F(ConformanceTest, testPutOlderDocumentVersion)
 
     Result result = spi->put(bucket, Timestamp(5), doc1, context);
     const BucketInfo info1 = spi->getBucketInfo(bucket).getBucketInfo();
-    spi->flush(bucket, context);
     {
         EXPECT_EQ(1, (int)info1.getDocumentCount());
         EXPECT_TRUE(info1.getEntryCount() >= info1.getDocumentCount());
@@ -678,7 +661,6 @@ TEST_F(ConformanceTest, testPutOlderDocumentVersion)
     result = spi->put(bucket, Timestamp(4), doc2, context);
     {
         const BucketInfo info2 = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
 
         EXPECT_EQ(1, (int)info2.getDocumentCount());
         EXPECT_TRUE(info2.getEntryCount() >= info1.getDocumentCount());
@@ -712,7 +694,6 @@ TEST_F(ConformanceTest, testPutDuplicate)
     BucketChecksum checksum;
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
         EXPECT_EQ(1, (int)info.getDocumentCount());
         checksum = info.getChecksum();
     }
@@ -721,7 +702,6 @@ TEST_F(ConformanceTest, testPutDuplicate)
 
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
         EXPECT_EQ(1, (int)info.getDocumentCount());
         EXPECT_EQ(checksum, info.getChecksum());
     }
@@ -746,7 +726,6 @@ TEST_F(ConformanceTest, testRemove)
 
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
 
         EXPECT_EQ(1, (int)info.getDocumentCount());
         EXPECT_TRUE(info.getChecksum() != 0);
@@ -764,7 +743,6 @@ TEST_F(ConformanceTest, testRemove)
 
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
 
         EXPECT_EQ(0, (int)info.getDocumentCount());
         EXPECT_EQ(0, (int)info.getChecksum());
@@ -791,7 +769,6 @@ TEST_F(ConformanceTest, testRemove)
                                        context);
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
 
         EXPECT_EQ(0, (int)info.getDocumentCount());
         EXPECT_EQ(0, (int)info.getChecksum());
@@ -799,7 +776,6 @@ TEST_F(ConformanceTest, testRemove)
     }
 
     Result result4 = spi->put(bucket, Timestamp(9), doc1, context);
-    spi->flush(bucket, context);
 
     EXPECT_TRUE(!result4.hasError());
 
@@ -809,7 +785,6 @@ TEST_F(ConformanceTest, testRemove)
                                        context);
     {
         const BucketInfo info = spi->getBucketInfo(bucket).getBucketInfo();
-        spi->flush(bucket, context);
 
         EXPECT_EQ(0, (int)info.getDocumentCount());
         EXPECT_EQ(0, (int)info.getChecksum());
@@ -847,7 +822,6 @@ TEST_F(ConformanceTest, testRemoveMerge)
                                                 Timestamp(10),
                                                 removeId,
                                                 context);
-        spi->flush(bucket, context);
         EXPECT_EQ(Result::ErrorType::NONE, removeResult.getErrorCode());
         EXPECT_EQ(false, removeResult.wasFound());
     }
@@ -875,7 +849,6 @@ TEST_F(ConformanceTest, testRemoveMerge)
                                                 Timestamp(11),
                                                 removeId,
                                                 context);
-        spi->flush(bucket, context);
         EXPECT_EQ(Result::ErrorType::NONE, removeResult.getErrorCode());
         EXPECT_EQ(false, removeResult.wasFound());
     }
@@ -903,7 +876,6 @@ TEST_F(ConformanceTest, testRemoveMerge)
                                                 Timestamp(7),
                                                 removeId,
                                                 context);
-        spi->flush(bucket, context);
         EXPECT_EQ(Result::ErrorType::NONE, removeResult.getErrorCode());
         EXPECT_EQ(false, removeResult.wasFound());
     }
@@ -946,7 +918,6 @@ TEST_F(ConformanceTest, testUpdate)
     {
         UpdateResult result = spi->update(bucket, Timestamp(3), update,
                                           context);
-        spi->flush(bucket, context);
         EXPECT_EQ(Result(), Result(result));
         EXPECT_EQ(Timestamp(0), result.getExistingTimestamp());
     }
@@ -955,7 +926,6 @@ TEST_F(ConformanceTest, testUpdate)
     {
         UpdateResult result = spi->update(bucket, Timestamp(4), update,
                                           context);
-        spi->flush(bucket, context);
 
         EXPECT_EQ(Result::ErrorType::NONE, result.getErrorCode());
         EXPECT_EQ(Timestamp(3), result.getExistingTimestamp());
@@ -975,7 +945,6 @@ TEST_F(ConformanceTest, testUpdate)
     }
 
     spi->remove(bucket, Timestamp(5), doc1->getId(), context);
-    spi->flush(bucket, context);
 
     {
         GetResult result = spi->get(bucket,
@@ -991,7 +960,6 @@ TEST_F(ConformanceTest, testUpdate)
     {
         UpdateResult result = spi->update(bucket, Timestamp(6), update,
                                           context);
-        spi->flush(bucket, context);
 
         EXPECT_EQ(Result::ErrorType::NONE, result.getErrorCode());
         EXPECT_EQ(Timestamp(0), result.getExistingTimestamp());
@@ -1009,7 +977,6 @@ TEST_F(ConformanceTest, testUpdate)
         // Document does not exist (and therefore its condition cannot match by definition),
         // but since CreateIfNonExistent is set it should be auto-created anyway.
         UpdateResult result = spi->update(bucket, Timestamp(7), update, context);
-        spi->flush(bucket, context);
         EXPECT_EQ(Result::ErrorType::NONE, result.getErrorCode());
         EXPECT_EQ(Timestamp(7), result.getExistingTimestamp());
     }
@@ -1044,7 +1011,6 @@ TEST_F(ConformanceTest, testGet)
     }
 
     spi->put(bucket, Timestamp(3), doc1, context);
-    spi->flush(bucket, context);
 
     {
         GetResult result = spi->get(bucket, document::AllFields(),
@@ -1054,7 +1020,6 @@ TEST_F(ConformanceTest, testGet)
     }
 
     spi->remove(bucket, Timestamp(4), doc1->getId(), context);
-    spi->flush(bucket, context);
 
     {
         GetResult result = spi->get(bucket, document::AllFields(),
@@ -1168,7 +1133,6 @@ TEST_F(ConformanceTest, testIterateAllDocsNewestVersionOnly)
         spi->put(b, newTimestamp, newDoc, context);
         newDocs.push_back(DocAndTimestamp(newDoc, newTimestamp));
     }
-    spi->flush(b, context);
 
     CreateIteratorResult iter(createIterator(*spi, b, createSelection("")));
 
@@ -1249,7 +1213,6 @@ TEST_F(ConformanceTest, testIterateMatchTimestampRange)
                     DocAndTimestamp(doc, Timestamp(1000 + i)));
         }
     }
-    spi->flush(b, context);
 
     Selection sel = Selection(DocumentSelection(""));
     sel.setFromTimestamp(fromTimestamp);
@@ -1295,7 +1258,6 @@ TEST_F(ConformanceTest, testIterateExplicitTimestampSubset)
                                Timestamp(2000),
                                docsToVisit.front().doc->getId(), context)
                    .wasFound());
-    spi->flush(b, context);
 
     timestampsToVisit.push_back(Timestamp(2000));
     removes.insert(docsToVisit.front().doc->getId().toString());
@@ -1339,7 +1301,6 @@ TEST_F(ConformanceTest, testIterateRemoves)
             nonRemovedDocs.push_back(docs[i]);
         }
     }
-    spi->flush(b, context);
 
     // First, test iteration without removes
     {
@@ -1387,7 +1348,6 @@ TEST_F(ConformanceTest, testIterateMatchSelection)
                     DocAndTimestamp(doc, Timestamp(1000 + i)));
         }
     }
-    spi->flush(b, context);
 
     CreateIteratorResult iter(
             createIterator(*spi,
@@ -1416,7 +1376,6 @@ TEST_F(ConformanceTest, testIterationRequiringDocumentIdOnlyMatching)
     // remove entry for it regardless.
     EXPECT_TRUE(
             !spi->remove(b, Timestamp(2000), removedId, context).wasFound());
-    spi->flush(b, context);
 
     Selection sel(createSelection("id == '" + removedId.toString() + "'"));
 
@@ -1530,7 +1489,6 @@ TEST_F(ConformanceTest, testDeleteBucket)
     spi->createBucket(bucket, context);
 
     spi->put(bucket, Timestamp(3), doc1, context);
-    spi->flush(bucket, context);
 
     spi->deleteBucket(bucket, context);
     testDeleteBucketPostCondition(spi, bucket, *doc1);
@@ -1586,8 +1544,6 @@ TEST_F(ConformanceTest, testSplitNormalCase)
         spi->put(bucketC, Timestamp(i + 1), doc1, context);
     }
 
-    spi->flush(bucketC, context);
-
     spi->split(bucketC, bucketA, bucketB, context);
     testSplitNormalCasePostCondition(spi, bucketA, bucketB, bucketC,
                                      testDocMan);
@@ -1657,28 +1613,23 @@ TEST_F(ConformanceTest, testSplitTargetExists)
         spi->put(bucketC, Timestamp(i + 1), doc1, context);
     }
 
-    spi->flush(bucketC, context);
 
     for (uint32_t i = 10; i < 20; ++i) {
         Document::SP doc1 = testDocMan.createRandomDocumentAtLocation(0x06, i);
         spi->put(bucketB, Timestamp(i + 1), doc1, context);
     }
-    spi->flush(bucketB, context);
     EXPECT_TRUE(!spi->getBucketInfo(bucketB).getBucketInfo().isActive());
 
     for (uint32_t i = 10; i < 20; ++i) {
         Document::SP doc1 = testDocMan.createRandomDocumentAtLocation(0x06, i);
         spi->put(bucketC, Timestamp(i + 1), doc1, context);
     }
-    spi->flush(bucketC, context);
 
     for (uint32_t i = 20; i < 25; ++i) {
         Document::SP doc1 = testDocMan.createRandomDocumentAtLocation(0x06, i);
         spi->put(bucketB, Timestamp(i + 1), doc1, context);
     }
 
-    spi->flush(bucketB, context);
-
     spi->split(bucketC, bucketA, bucketB, context);
     testSplitTargetExistsPostCondition(spi, bucketA, bucketB, bucketC,
                                        testDocMan);
@@ -1745,8 +1696,6 @@ TEST_F(ConformanceTest, testSplitSingleDocumentInSource)
     Document::SP doc = testDocMan.createRandomDocumentAtLocation(0x06, 0);
     spi->put(source, Timestamp(1), doc, context);
 
-    spi->flush(source, context);
-
     spi->split(source, target1, target2, context);
     testSplitSingleDocumentInSourcePostCondition(
             spi, source, target1, target2, testDocMan);
@@ -1804,7 +1753,6 @@ ConformanceTest::createAndPopulateJoinSourceBuckets(
                     source1.getBucketId().getId(), i));
         spi.put(source1, Timestamp(i + 1), doc, context);
     }
-    spi.flush(source1, context);
 
     for (uint32_t i = 10; i < 20; ++i) {
         Document::SP doc(
@@ -1812,7 +1760,6 @@ ConformanceTest::createAndPopulateJoinSourceBuckets(
                     source2.getBucketId().getId(), i));
         spi.put(source2, Timestamp(i + 1), doc, context);
     }
-    spi.flush(source2, context);
 }
 
 void
@@ -1912,21 +1859,17 @@ TEST_F(ConformanceTest, testJoinTargetExists)
         spi->put(bucketA, Timestamp(i + 1), doc1, context);
     }
 
-    spi->flush(bucketA, context);
 
     for (uint32_t i = 10; i < 20; ++i) {
         Document::SP doc1 = testDocMan.createRandomDocumentAtLocation(0x06, i);
         spi->put(bucketB, Timestamp(i + 1), doc1, context);
     }
-    spi->flush(bucketB, context);
 
     for (uint32_t i = 20; i < 30; ++i) {
         Document::SP doc1 = testDocMan.createRandomDocumentAtLocation(0x06, i);
         spi->put(bucketC, Timestamp(i + 1), doc1, context);
     }
 
-    spi->flush(bucketC, context);
-
     spi->join(bucketA, bucketB, bucketC, context);
     testJoinTargetExistsPostCondition(spi, bucketA, bucketB, bucketC,
                                       testDocMan);
@@ -1991,7 +1934,6 @@ ConformanceTest::populateBucket(const Bucket& b,
                 location, i);
         spi.put(b, Timestamp(i + 1), doc1, context);
     }
-    spi.flush(b, context);
 }
 
 TEST_F(ConformanceTest, testJoinOneBucket)
@@ -2150,7 +2092,6 @@ TEST_F(ConformanceTest, testMaintain)
     spi->createBucket(bucket, context);
 
     spi->put(bucket, Timestamp(3), doc1, context);
-    spi->flush(bucket, context);
 
     EXPECT_EQ(Result::ErrorType::NONE,
                          spi->maintain(bucket, LOW).getErrorCode());
@@ -2229,7 +2170,6 @@ TEST_F(SingleDocTypeConformanceTest, testBucketActivationSplitAndJoin)
     spi->createBucket(bucketC, context);
     spi->put(bucketC, Timestamp(1), doc1, context);
     spi->put(bucketC, Timestamp(2), doc2, context);
-    spi->flush(bucketC, context);
 
     spi->setActiveState(bucketC, BucketInfo::ACTIVE);
     EXPECT_TRUE(spi->getBucketInfo(bucketC).getBucketInfo().isActive());
@@ -2304,14 +2244,11 @@ TEST_F(ConformanceTest, testRemoveEntry)
     spi->createBucket(bucket, context);
 
     spi->put(bucket, Timestamp(3), doc1, context);
-    spi->flush(bucket, context);
     BucketInfo info1 = spi->getBucketInfo(bucket).getBucketInfo();
 
     {
         spi->put(bucket, Timestamp(4), doc2, context);
-        spi->flush(bucket, context);
         spi->removeEntry(bucket, Timestamp(4), context);
-        spi->flush(bucket, context);
         BucketInfo info2 = spi->getBucketInfo(bucket).getBucketInfo();
         EXPECT_EQ(info1, info2);
     }
@@ -2319,9 +2256,7 @@ TEST_F(ConformanceTest, testRemoveEntry)
     // Test case where there exists a previous version of the document.
     {
         spi->put(bucket, Timestamp(5), doc1, context);
-        spi->flush(bucket, context);
         spi->removeEntry(bucket, Timestamp(5), context);
-        spi->flush(bucket, context);
         BucketInfo info2 = spi->getBucketInfo(bucket).getBucketInfo();
         EXPECT_EQ(info1, info2);
     }
@@ -2329,14 +2264,11 @@ TEST_F(ConformanceTest, testRemoveEntry)
     // Test case where the newest document version after removeEntrying is a remove.
     {
         spi->remove(bucket, Timestamp(6), doc1->getId(), context);
-        spi->flush(bucket, context);
         BucketInfo info2 = spi->getBucketInfo(bucket).getBucketInfo();
         EXPECT_EQ(uint32_t(0), info2.getDocumentCount());
 
         spi->put(bucket, Timestamp(7), doc1, context);
-        spi->flush(bucket, context);
         spi->removeEntry(bucket, Timestamp(7), context);
-        spi->flush(bucket, context);
         BucketInfo info3 = spi->getBucketInfo(bucket).getBucketInfo();
         EXPECT_EQ(info2, info3);
     }
@@ -2395,9 +2327,6 @@ TEST_F(ConformanceTest, testBucketSpaces)
     spi->put(bucket01, Timestamp(4), doc2, context);
     spi->put(bucket11, Timestamp(5), doc3, context);
     spi->put(bucket12, Timestamp(6), doc4, context);
-    spi->flush(bucket01, context);
-    spi->flush(bucket11, context);
-    spi->flush(bucket12, context);
     // Check bucket lists
     assertBucketList(*spi, bucketSpace0, partId, { bucketId1 });
     assertBucketList(*spi, bucketSpace1, partId, { bucketId1, bucketId2 });
diff --git a/persistence/src/vespa/persistence/spi/abstractpersistenceprovider.h b/persistence/src/vespa/persistence/spi/abstractpersistenceprovider.h
index 557a9ec2edd..cbd76951004 100644
--- a/persistence/src/vespa/persistence/spi/abstractpersistenceprovider.h
+++ b/persistence/src/vespa/persistence/spi/abstractpersistenceprovider.h
@@ -41,11 +41,6 @@ public:
     Result removeEntry(const Bucket&, Timestamp, Context&) override { return Result(); }
 
     /**
-     * Default impl is getBucketInfo();
-     */
-    Result flush(const Bucket&, Context&) override { return Result(); }
-
-    /**
      * Default impl is remove().
      */
     RemoveResult removeIfFound(const Bucket&, Timestamp, const DocumentId&, Context&) override;
diff --git a/persistence/src/vespa/persistence/spi/persistenceprovider.h b/persistence/src/vespa/persistence/spi/persistenceprovider.h
index 857630e2606..c70d5e3f1c3 100644
--- a/persistence/src/vespa/persistence/spi/persistenceprovider.h
+++ b/persistence/src/vespa/persistence/spi/persistenceprovider.h
@@ -202,30 +202,6 @@ struct PersistenceProvider
     virtual UpdateResult update(const Bucket&, Timestamp timestamp, const DocumentUpdateSP& update, Context&) = 0;
 
     /**
-     * The service layer may choose to batch certain commands. This means that
-     * the service layer will lock the bucket only once, then perform several
-     * commands, and finally get the bucket info from the bucket, and then
-     * flush it.  This can be used to improve performance by caching the
-     * modifications, and persisting them to disk only when flush is called.
-     * The service layer guarantees that after one of these operations, flush()
-     * is called, regardless of whether the operation succeeded or not, before
-     * another bucket is processed in the same worker thead. The following
-     * operations can be batched and have the guarantees
-     * above:
-     * - put
-     * - get
-     * - remove (all versions)
-     * - update
-     * - revert
-     * - join
-     * <p/>
-     * A provider may of course choose to not sync to disk at flush time either,
-     * but then data may be more prone to being lost on node issues, and the
-     * provider must figure out when to flush its cache itself.
-     */
-    virtual Result flush(const Bucket&, Context&) = 0;
-
-    /**
      * Retrieves the latest version of the document specified by the
      * document id. If no versions were found, or the document was removed,
      * the result should be successful, but contain no document (see GetResult).
diff --git a/searchcore/src/apps/proton/downpersistence.cpp b/searchcore/src/apps/proton/downpersistence.cpp
index 4b911eb6d2b..d4ec9cee395 100644
--- a/searchcore/src/apps/proton/downpersistence.cpp
+++ b/searchcore/src/apps/proton/downpersistence.cpp
@@ -98,12 +98,6 @@ UpdateResult DownPersistence::update(const Bucket&, Timestamp,
                         errorResult.getErrorMessage());
 }
 
-Result
-DownPersistence::flush(const Bucket&, Context&)
-{
-    return errorResult;
-}
-
 GetResult
 DownPersistence::get(const Bucket&, const document::FieldSet&,
                      const DocumentId&, Context&) const
diff --git a/searchcore/src/apps/proton/downpersistence.h b/searchcore/src/apps/proton/downpersistence.h
index 0a602c4467e..8cdac7aaa1b 100644
--- a/searchcore/src/apps/proton/downpersistence.h
+++ b/searchcore/src/apps/proton/downpersistence.h
@@ -37,7 +37,6 @@ public:
     RemoveResult removeIfFound(const Bucket&, Timestamp timestamp, const DocumentId& id, Context&) override;
     Result removeEntry(const Bucket&, Timestamp, Context&) override;
     UpdateResult update(const Bucket&, Timestamp timestamp, const DocumentUpdateSP& update, Context&) override;
-    Result flush(const Bucket&, Context&) override;
     GetResult get(const Bucket&, const document::FieldSet& fieldSet, const DocumentId& id, Context&) const override;
 
     CreateIteratorResult createIterator(const Bucket&, const document::FieldSet& fieldSet,
diff --git a/storage/src/tests/persistence/common/persistenceproviderwrapper.cpp b/storage/src/tests/persistence/common/persistenceproviderwrapper.cpp
index 05e51993f49..fb80c25bfb7 100644
--- a/storage/src/tests/persistence/common/persistenceproviderwrapper.cpp
+++ b/storage/src/tests/persistence/common/persistenceproviderwrapper.cpp
@@ -145,15 +145,6 @@ PersistenceProviderWrapper::get(const spi::Bucket& bucket,
     return _spi.get(bucket, fieldSet, id, context);
 }
 
-spi::Result
-PersistenceProviderWrapper::flush(const spi::Bucket& bucket,
-                                  spi::Context& context)
-{
-    LOG_SPI("flush(" << bucket << ")");
-    CHECK_ERROR(spi::Result, FAIL_FLUSH);
-    return _spi.flush(bucket, context);
-}
-
 spi::CreateIteratorResult
 PersistenceProviderWrapper::createIterator(const spi::Bucket& bucket,
                                            const document::FieldSet& fields,
diff --git a/storage/src/tests/persistence/common/persistenceproviderwrapper.h b/storage/src/tests/persistence/common/persistenceproviderwrapper.h
index 511ced02118..9bd3653e8a1 100644
--- a/storage/src/tests/persistence/common/persistenceproviderwrapper.h
+++ b/storage/src/tests/persistence/common/persistenceproviderwrapper.h
@@ -36,7 +36,6 @@ public:
         FAIL_REPLACE_WITH_REMOVE = 1 << 6,
         FAIL_UPDATE           = 1 << 7,
         FAIL_REVERT           = 1 << 8,
-        FAIL_FLUSH            = 1 << 9,
         FAIL_CREATE_ITERATOR  = 1 << 10,
         FAIL_ITERATE          = 1 << 11,
         FAIL_DESTROY_ITERATOR = 1 << 12,
@@ -44,7 +43,7 @@ public:
         FAIL_SPLIT            = 1 << 14,
         FAIL_JOIN             = 1 << 15,
         FAIL_CREATE_BUCKET    = 1 << 16,
-        FAIL_BUCKET_PERSISTENCE = FAIL_PUT|FAIL_REMOVE|FAIL_UPDATE|FAIL_REVERT|FAIL_FLUSH,
+        FAIL_BUCKET_PERSISTENCE = FAIL_PUT|FAIL_REMOVE|FAIL_UPDATE|FAIL_REVERT,
         FAIL_ALL_OPERATIONS   = 0xffff,
         // TODO: add more as needed
     };
@@ -55,7 +54,7 @@ private:
     uint32_t _failureMask;
 public:
     PersistenceProviderWrapper(spi::PersistenceProvider& spi);
-    ~PersistenceProviderWrapper();
+    ~PersistenceProviderWrapper() override;
 
     /**
      * Explicitly set result to anything != NONE to have all operations
@@ -96,7 +95,6 @@ public:
     spi::GetResult get(const spi::Bucket&, const document::FieldSet&,
                        const spi::DocumentId&, spi::Context&) const override ;
 
-    spi::Result flush(const spi::Bucket&, spi::Context&) override;
     spi::CreateIteratorResult createIterator(const spi::Bucket&, const document::FieldSet&, const spi::Selection&,
                                              spi::IncludedVersions versions, spi::Context&) override;
 
diff --git a/storage/src/tests/persistence/mergehandlertest.cpp b/storage/src/tests/persistence/mergehandlertest.cpp
index 0b2baab5652..7e7a76b95a8 100644
--- a/storage/src/tests/persistence/mergehandlertest.cpp
+++ b/storage/src/tests/persistence/mergehandlertest.cpp
@@ -626,8 +626,7 @@ MergeHandlerTest::createDummyGetBucketDiff(int timestampOffset,
 }
 
 TEST_F(MergeHandlerTest, spi_flush_guard) {
-    PersistenceProviderWrapper providerWrapper(
-            getPersistenceProvider());
+    PersistenceProviderWrapper providerWrapper(getPersistenceProvider());
     MergeHandler handler(providerWrapper, getEnv());
 
     providerWrapper.setResult(
@@ -635,8 +634,7 @@ TEST_F(MergeHandlerTest, spi_flush_guard) {
 
     setUpChain(MIDDLE);
     // Fail applying unrevertable remove
-    providerWrapper.setFailureMask(
-            PersistenceProviderWrapper::FAIL_REMOVE);
+    providerWrapper.setFailureMask(PersistenceProviderWrapper::FAIL_REMOVE);
     providerWrapper.clearOperationLog();
 
     try {
@@ -645,11 +643,6 @@ TEST_F(MergeHandlerTest, spi_flush_guard) {
     } catch (const std::runtime_error& e) {
         EXPECT_TRUE(std::string(e.what()).find("Failed remove") != std::string::npos);
     }
-    // Test that we always flush after applying diff locally, even when
-    // errors are encountered.
-    const std::vector<std::string>& opLog(providerWrapper.getOperationLog());
-    ASSERT_FALSE(opLog.empty());
-    EXPECT_EQ("flush(Bucket(0x40000000000004d2, partition 0))", opLog.back());
 }
 
 TEST_F(MergeHandlerTest, bucket_not_found_in_db) {
@@ -901,7 +894,6 @@ TEST_F(MergeHandlerTest, apply_bucket_diff_spi_failures) {
         { PersistenceProviderWrapper::FAIL_ITERATE, "iterate" },
         { PersistenceProviderWrapper::FAIL_PUT, "Failed put" },
         { PersistenceProviderWrapper::FAIL_REMOVE, "Failed remove" },
-        { PersistenceProviderWrapper::FAIL_FLUSH, "Failed flush" },
     };
 
     typedef ExpectedExceptionSpec* ExceptionIterator;
@@ -1058,7 +1050,6 @@ TEST_F(MergeHandlerTest, apply_bucket_diff_reply_spi_failures) {
             { PersistenceProviderWrapper::FAIL_ITERATE, "iterate" },
             { PersistenceProviderWrapper::FAIL_PUT, "Failed put" },
             { PersistenceProviderWrapper::FAIL_REMOVE, "Failed remove" },
-            { PersistenceProviderWrapper::FAIL_FLUSH, "Failed flush" },
         };
 
         typedef ExpectedExceptionSpec* ExceptionIterator;
diff --git a/storage/src/tests/persistence/persistencetestutils.cpp b/storage/src/tests/persistence/persistencetestutils.cpp
index e32fc056413..25c0a36a7f5 100644
--- a/storage/src/tests/persistence/persistencetestutils.cpp
+++ b/storage/src/tests/persistence/persistencetestutils.cpp
@@ -159,7 +159,6 @@ PersistenceTestUtils::doPutOnDisk(
 
     getPersistenceProvider().put(spi::Bucket(b), timestamp, doc, context);
 
-    getPersistenceProvider().flush(b, context);
     return doc;
 }
 
diff --git a/storage/src/vespa/storage/persistence/mergehandler.cpp b/storage/src/vespa/storage/persistence/mergehandler.cpp
index e5e358cbb60..d47ed28f636 100644
--- a/storage/src/vespa/storage/persistence/mergehandler.cpp
+++ b/storage/src/vespa/storage/persistence/mergehandler.cpp
@@ -91,40 +91,6 @@ public:
     }
 };
 
-class FlushGuard
-{
-    spi::PersistenceProvider& _spi;
-    spi::Bucket _bucket;
-    spi::Context& _context;
-    bool _hasFlushed;
-public:
-    FlushGuard(spi::PersistenceProvider& spi,
-               const spi::Bucket& bucket,
-               spi::Context& context)
-        : _spi(spi),
-          _bucket(bucket),
-          _context(context),
-          _hasFlushed(false)
-    {}
-    ~FlushGuard()
-    {
-        if (!_hasFlushed) {
-            LOG(debug, "Auto-flushing %s", _bucket.toString().c_str());
-            spi::Result result =_spi.flush(_bucket, _context);
-            if (result.hasError()) {
-                LOG(debug, "Flush %s failed: %s",
-                    _bucket.toString().c_str(),
-                    result.toString().c_str());
-            }
-        }
-    }
-    void flush() {
-        LOG(debug, "Flushing %s", _bucket.toString().c_str());
-        _hasFlushed = true;
-        checkResult(_spi.flush(_bucket, _context), _bucket, "flush");
-    }
-};
-
 struct IndirectDocEntryTimestampPredicate
 {
     bool operator()(const spi::DocEntry::UP& e1,
@@ -607,8 +573,6 @@ MergeHandler::applyDiffLocally(
     std::vector<spi::DocEntry::UP> entries;
     populateMetaData(bucket, MAX_TIMESTAMP, entries, context);
 
-    FlushGuard flushGuard(_spi, bucket, context);
-
     std::shared_ptr<const document::DocumentTypeRepo> repo(_env._component.getTypeRepo());
     assert(repo.get() != nullptr);
 
@@ -702,8 +666,6 @@ MergeHandler::applyDiffLocally(
     LOG(debug, "Merge(%s): Applied %u entries locally from ApplyBucketDiff.",
         bucket.toString().c_str(), addedCount);
 
-    flushGuard.flush();
-
     spi::BucketInfoResult infoResult(_spi.getBucketInfo(bucket));
     if (infoResult.getErrorCode() != spi::Result::ErrorType::NONE) {
         LOG(warning, "Failed to get bucket info for %s: %s",
diff --git a/storage/src/vespa/storage/persistence/persistencethread.cpp b/storage/src/vespa/storage/persistence/persistencethread.cpp
index d1da25269cf..aaf62a85e87 100644
--- a/storage/src/vespa/storage/persistence/persistencethread.cpp
+++ b/storage/src/vespa/storage/persistence/persistencethread.cpp
@@ -607,10 +607,6 @@ PersistenceThread::handleJoinBuckets(api::JoinBucketsCommand& cmd, spi::Context
     if (!checkForError(result, *tracker)) {
         return tracker;
     }
-    result = _spi.flush(spi::Bucket(destBucket, spi::PartitionId(_env._partition)), context);
-    if (!checkForError(result, *tracker)) {
-        return tracker;
-    }
     uint64_t lastModified = 0;
     for (uint32_t i = 0; i < cmd.getSourceBuckets().size(); i++) {
         document::Bucket srcBucket(destBucket.getBucketSpace(), cmd.getSourceBuckets()[i]);
diff --git a/storage/src/vespa/storage/persistence/processallhandler.cpp b/storage/src/vespa/storage/persistence/processallhandler.cpp
index 5b94a3da027..f37c6723933 100644
--- a/storage/src/vespa/storage/persistence/processallhandler.cpp
+++ b/storage/src/vespa/storage/persistence/processallhandler.cpp
@@ -83,9 +83,9 @@ MessageTracker::UP
 ProcessAllHandler::handleRemoveLocation(api::RemoveLocationCommand& cmd,
                                         spi::Context& context)
 {
-    MessageTracker::UP tracker(new MessageTracker(
+    auto tracker = std::make_unique<MessageTracker>(
                                        _env._metrics.removeLocation[cmd.getLoadType()],
-                                       _env._component.getClock()));
+                                       _env._component.getClock());
 
     LOG(debug, "RemoveLocation(%s): using selection '%s'",
         cmd.getBucketId().toString().c_str(),
@@ -99,13 +99,8 @@ ProcessAllHandler::handleRemoveLocation(api::RemoveLocationCommand& cmd,
                                 processor,
                                 spi::NEWEST_DOCUMENT_ONLY,
                                 context);
-    spi::Result result = _spi.flush(bucket, context);
-    uint32_t code = _env.convertErrorCode(result);
-    if (code == 0) {
-        tracker->setReply(std::make_shared<api::RemoveLocationReply>(cmd, processor._n_removed));
-    } else {
-        tracker->fail(code, result.getErrorMessage());
-    }
+
+    tracker->setReply(std::make_shared<api::RemoveLocationReply>(cmd, processor._n_removed));
 
     return tracker;
 }
@@ -114,9 +109,9 @@ MessageTracker::UP
 ProcessAllHandler::handleStatBucket(api::StatBucketCommand& cmd,
                                     spi::Context& context)
 {
-    MessageTracker::UP tracker(new MessageTracker(
+    auto tracker = std::make_unique<MessageTracker>(
                                        _env._metrics.statBucket[cmd.getLoadType()],
-                                       _env._component.getClock()));
+                                       _env._component.getClock());
     std::ostringstream ost;
 
     ost << "Persistence bucket " << cmd.getBucketId()
diff --git a/storage/src/vespa/storage/persistence/provider_error_wrapper.cpp b/storage/src/vespa/storage/persistence/provider_error_wrapper.cpp
index fe947bff4d5..76c420e76e6 100644
--- a/storage/src/vespa/storage/persistence/provider_error_wrapper.cpp
+++ b/storage/src/vespa/storage/persistence/provider_error_wrapper.cpp
@@ -118,12 +118,6 @@ ProviderErrorWrapper::get(const spi::Bucket& bucket,
     return checkResult(_impl.get(bucket, fieldSet, docId, context));
 }
 
-spi::Result
-ProviderErrorWrapper::flush(const spi::Bucket& bucket, spi::Context& context)
-{
-    return checkResult(_impl.flush(bucket, context));
-}
-
 spi::CreateIteratorResult
 ProviderErrorWrapper::createIterator(const spi::Bucket& bucket,
                                         const document::FieldSet& fieldSet,
diff --git a/storage/src/vespa/storage/persistence/provider_error_wrapper.h b/storage/src/vespa/storage/persistence/provider_error_wrapper.h
index 3b5ace90d13..292eb004223 100644
--- a/storage/src/vespa/storage/persistence/provider_error_wrapper.h
+++ b/storage/src/vespa/storage/persistence/provider_error_wrapper.h
@@ -52,7 +52,6 @@ public:
     spi::RemoveResult removeIfFound(const spi::Bucket&, spi::Timestamp, const document::DocumentId&, spi::Context&) override;
     spi::UpdateResult update(const spi::Bucket&, spi::Timestamp, const spi::DocumentUpdateSP&, spi::Context&) override;
     spi::GetResult get(const spi::Bucket&, const document::FieldSet&, const document::DocumentId&, spi::Context&) const override;
-    spi::Result flush(const spi::Bucket&, spi::Context&) override;
     spi::CreateIteratorResult createIterator(const spi::Bucket&, const document::FieldSet&, const spi::Selection&,
                                              spi::IncludedVersions versions, spi::Context&) override;
     spi::IterateResult iterate(spi::IteratorId, uint64_t maxByteSize, spi::Context&) const override;