Fix a bug where KMeans clusters could change on schemeshard restart (#18979) (#19004)

Author: vitalif

ydb/core/tx/schemeshard/schemeshard_build_index__progress.cpp

@@ -1021,7 +1021,8 @@ struct TSchemeShard::TIndexBuilder::TTxProgress: public TSchemeShard::TIndexBuil
             return false;
         }
 
-        if (!buildInfo.Sample.Rows.empty()) {
+        if (buildInfo.KMeans.State == TIndexBuildInfo::TKMeans::Sample &&
+            !buildInfo.Sample.Rows.empty()) {
             if (buildInfo.Sample.State == TIndexBuildInfo::TSample::EState::Collect) {
                 LOG_D("FillVectorIndex SendUploadSampleKRequest " << buildInfo.DebugString());
                 SendUploadSampleKRequest(buildInfo);
@@ -1033,7 +1034,8 @@ struct TSchemeShard::TIndexBuilder::TTxProgress: public TSchemeShard::TIndexBuil
         ClearDoneShards(txc, buildInfo);
 
         if (!buildInfo.Sample.Rows.empty()) {
-            if (buildInfo.KMeans.NextState()) {
+            if (buildInfo.KMeans.State == TIndexBuildInfo::TKMeans::Sample) {
+                buildInfo.KMeans.State = TIndexBuildInfo::TKMeans::Reshuffle;
                 LOG_D("FillVectorIndex NextState " << buildInfo.DebugString());
                 PersistKMeansState(txc, buildInfo);
                 Progress(BuildId);
@@ -1603,29 +1605,6 @@ struct TSchemeShard::TIndexBuilder::TTxReplySampleK: public TSchemeShard::TIndex
             }
 
             NIceDb::TNiceDb db(txc.DB);
-            if (record.ProbabilitiesSize()) {
-                Y_ENSURE(record.RowsSize());
-                auto& probabilities = record.GetProbabilities();
-                auto& rows = *record.MutableRows();
-                Y_ENSURE(probabilities.size() == rows.size());
-                auto& sample = buildInfo.Sample.Rows;
-                auto from = sample.size();
-                for (int i = 0; i != probabilities.size(); ++i) {
-                    if (probabilities[i] >= buildInfo.Sample.MaxProbability) {
-                        break;
-                    }
-                    sample.emplace_back(probabilities[i], std::move(rows[i]));
-                }
-                if (buildInfo.Sample.MakeWeakTop(buildInfo.KMeans.K)) {
-                    from = 0;
-                }
-                for (; from < sample.size(); ++from) {
-                    db.Table<Schema::KMeansTreeSample>().Key(buildInfo.Id, from).Update(
-                        NIceDb::TUpdate<Schema::KMeansTreeSample::Probability>(sample[from].P),
-                        NIceDb::TUpdate<Schema::KMeansTreeSample::Data>(sample[from].Row)
-                    );
-                }
-            }
 
             TBillingStats stats{0, 0, record.GetReadRows(), record.GetReadBytes()};
             shardStatus.Processed += stats;
@@ -1639,6 +1618,32 @@ struct TSchemeShard::TIndexBuilder::TTxReplySampleK: public TSchemeShard::TIndex
             switch (shardStatus.Status) {
             case  NKikimrIndexBuilder::EBuildStatus::DONE:
                 if (buildInfo.InProgressShards.erase(shardIdx)) {
+                    if (record.ProbabilitiesSize()) {
+                        Y_ENSURE(record.RowsSize());
+                        auto& probabilities = record.GetProbabilities();
+                        auto& rows = *record.MutableRows();
+                        Y_ENSURE(probabilities.size() == rows.size());
+                        auto& sample = buildInfo.Sample.Rows;
+                        auto from = sample.size();
+                        for (int i = 0; i != probabilities.size(); ++i) {
+                            if (probabilities[i] >= buildInfo.Sample.MaxProbability) {
+                                break;
+                            }
+                            sample.emplace_back(probabilities[i], std::move(rows[i]));
+                        }
+                        if (buildInfo.Sample.MakeWeakTop(buildInfo.KMeans.K)) {
+                            from = 0;
+                        }
+                        for (; from < sample.size(); ++from) {
+                            db.Table<Schema::KMeansTreeSample>().Key(buildInfo.Id, from).Update(
+                                NIceDb::TUpdate<Schema::KMeansTreeSample::Probability>(sample[from].P),
+                                NIceDb::TUpdate<Schema::KMeansTreeSample::Data>(sample[from].Row)
+                            );
+                        }
+                        for (; from < 2*buildInfo.KMeans.K; ++from) {
+                            db.Table<Schema::KMeansTreeSample>().Key(buildInfo.Id, from).Delete();
+                        }
+                    }
                     buildInfo.DoneShards.emplace_back(shardIdx);
                 }
                 break;

ydb/core/tx/schemeshard/schemeshard_info_types.h

@@ -3136,17 +3136,6 @@ struct TIndexBuildInfo: public TSimpleRefCount<TIndexBuildInfo> {
         bool NeedsAnotherParent() const noexcept {
             return Parent < ParentEnd();
         }
-        bool NeedsAnotherState() const noexcept {
-            return State == Sample /*|| State == Recompute*/;
-        }
-
-        bool NextState() noexcept {
-            if (!NeedsAnotherState()) {
-                return false;
-            }
-            State = static_cast<EState>(static_cast<ui32>(State) + 1);
-            return true;
-        }
 
         bool NextParent() noexcept {
             if (!NeedsAnotherParent()) {

ydb/core/tx/schemeshard/ut_index/ut_vector_index.cpp

@@ -6,7 +6,6 @@
 #include <ydb/core/tx/schemeshard/ut_helpers/helpers.h>
 #include <ydb/core/tx/schemeshard/ut_helpers/test_with_reboots.h>
 #include <ydb/core/testlib/tablet_helpers.h>
-#include <ydb/public/lib/deprecated/kicli/kicli.h>
 
 
 using namespace NKikimr;

ydb/core/tx/schemeshard/ut_index_build/ut_vector_index_build.cpp

@@ -188,7 +188,7 @@ Y_UNIT_TEST_SUITE (VectorIndexBuildTest) {
         auto descr = TestGetBuildIndex(runtime, tenantSchemeShard, "/MyRoot/ServerLessDB", buildIndexId);
         UNIT_ASSERT_VALUES_EQUAL(descr.GetIndexBuild().GetState(), Ydb::Table::IndexBuildState::STATE_DONE);
 
-        const TString meteringData = R"({"usage":{"start":0,"quantity":431,"finish":0,"unit":"request_unit","type":"delta"},"tags":{},"id":"109-72075186233409549-2-0-0-0-0-619-605-11328-10960","cloud_id":"CLOUD_ID_VAL","source_wt":0,"source_id":"sless-docapi-ydb-ss","resource_id":"DATABASE_ID_VAL","schema":"ydb.serverless.requests.v1","folder_id":"FOLDER_ID_VAL","version":"1.0.0"})""\n";
+        const TString meteringData = R"({"usage":{"start":0,"quantity":433,"finish":0,"unit":"request_unit","type":"delta"},"tags":{},"id":"109-72075186233409549-2-0-0-0-0-611-609-11032-11108","cloud_id":"CLOUD_ID_VAL","source_wt":0,"source_id":"sless-docapi-ydb-ss","resource_id":"DATABASE_ID_VAL","schema":"ydb.serverless.requests.v1","folder_id":"FOLDER_ID_VAL","version":"1.0.0"})""\n";
 
         UNIT_ASSERT_NO_DIFF(meteringMessages, meteringData);
 

ydb/core/tx/schemeshard/ut_vector_index_build_reboots/ut_vector_index_build_reboots.cpp

@@ -26,12 +26,16 @@ Y_UNIT_TEST_SUITE(VectorIndexBuildTestReboots) {
                     KeyColumnNames: ["key"]
                     SplitBoundary { KeyPrefix { Tuple { Optional { Uint32: 50 } } } }
                     SplitBoundary { KeyPrefix { Tuple { Optional { Uint32: 150 } } } }
+                    SplitBoundary { KeyPrefix { Tuple { Optional { Uint32: 250 } } } }
+                    SplitBoundary { KeyPrefix { Tuple { Optional { Uint32: 350 } } } }
                 )");
                 t.TestEnv->TestWaitNotification(runtime, t.TxId);
 
                 WriteVectorTableRows(runtime, TTestTxConfig::SchemeShard, ++t.TxId, "/MyRoot/dir/Table", true, 0, 0, 50);
                 WriteVectorTableRows(runtime, TTestTxConfig::SchemeShard, ++t.TxId, "/MyRoot/dir/Table", true, 1, 50, 150);
-                WriteVectorTableRows(runtime, TTestTxConfig::SchemeShard, ++t.TxId, "/MyRoot/dir/Table", true, 2, 150, 200);
+                WriteVectorTableRows(runtime, TTestTxConfig::SchemeShard, ++t.TxId, "/MyRoot/dir/Table", true, 2, 150, 250);
+                WriteVectorTableRows(runtime, TTestTxConfig::SchemeShard, ++t.TxId, "/MyRoot/dir/Table", true, 3, 250, 350);
+                WriteVectorTableRows(runtime, TTestTxConfig::SchemeShard, ++t.TxId, "/MyRoot/dir/Table", true, 4, 350, 400);
             }
 
             AsyncBuildVectorIndex(runtime,  ++t.TxId, TTestTxConfig::SchemeShard, "/MyRoot", "/MyRoot/dir/Table", "index1", "embedding", {"value"});
@@ -68,6 +72,14 @@ Y_UNIT_TEST_SUITE(VectorIndexBuildTestReboots) {
                                    {NLs::PathNotExist});
                 TestDescribeResult(DescribePath(runtime, indexPath + "/" + PostingTable + BuildSuffix1, true, true, true),
                                    {NLs::PathNotExist});
+
+                // Check row count in the posting table
+                {
+                    auto rows = CountRows(runtime, TTestTxConfig::SchemeShard, "/MyRoot/dir/Table/index1/indexImplPostingTable");
+                    Cerr << "... posting table contains " << rows << " rows" << Endl;
+                    UNIT_ASSERT_VALUES_EQUAL(rows, 400);
+                }
+
             }
         });
     }