Handle unhandled exceptions during build index on SchemeShard (#19246)

9 files changed, 365 insertions, 134 deletions

diff --git a/ydb/core/tx/schemeshard/schemeshard_build_index__cancel.cpp b/ydb/core/tx/schemeshard/schemeshard_build_index__cancel.cpp
index d520b6f2f66..760341aeed7 100644
--- a/ydb/core/tx/schemeshard/schemeshard_build_index__cancel.cpp
+++ b/ydb/core/tx/schemeshard/schemeshard_build_index__cancel.cpp
@@ -10,7 +10,7 @@ using namespace NTabletFlatExecutor;
 struct TSchemeShard::TIndexBuilder::TTxCancel: public TSchemeShard::TIndexBuilder::TTxSimple<TEvIndexBuilder::TEvCancelRequest, TEvIndexBuilder::TEvCancelResponse> {
 public:
     explicit TTxCancel(TSelf* self, TEvIndexBuilder::TEvCancelRequest::TPtr& ev)
-        : TTxSimple(self, ev, TXTYPE_CANCEL_INDEX_BUILD)
+        : TTxSimple(self, TIndexBuildId(ev->Get()->Record.GetIndexBuildId()), ev, TXTYPE_CANCEL_INDEX_BUILD)
     {}
 
     bool DoExecute(TTransactionContext& txc, const TActorContext&) override {
@@ -27,40 +27,39 @@ public:
         }
         const TPathId domainPathId = database.GetPathIdForDomain();
 
-        TIndexBuildId indexBuildId = TIndexBuildId(record.GetIndexBuildId());
-        const auto* indexBuildInfoPtr = Self->IndexBuilds.FindPtr(indexBuildId);
+        const auto* indexBuildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!indexBuildInfoPtr) {
             return Reply(
                 Ydb::StatusIds::NOT_FOUND,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> not found"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> not found"
             );
         }
         auto& indexBuildInfo = *indexBuildInfoPtr->Get();
         if (indexBuildInfo.DomainPathId != domainPathId) {
             return Reply(
                 Ydb::StatusIds::NOT_FOUND,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> not found in database <" << record.GetDatabaseName() << ">"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> not found in database <" << record.GetDatabaseName() << ">"
             );
         }
 
         if (indexBuildInfo.IsFinished()) {
             return Reply(
                 Ydb::StatusIds::PRECONDITION_FAILED,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> has been finished already"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> has been finished already"
             );
         }
 
         if (indexBuildInfo.IsCancellationRequested()) {
             return Reply(
                 Ydb::StatusIds::PRECONDITION_FAILED,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> canceling already"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> canceling already"
             );
         }
 
         if (indexBuildInfo.State > TIndexBuildInfo::EState::Filling) {
             return Reply(
                 Ydb::StatusIds::PRECONDITION_FAILED,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> are almost done, cancellation has no sense"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> are almost done, cancellation has no sense"
             );
         }
 
diff --git a/ydb/core/tx/schemeshard/schemeshard_build_index__create.cpp b/ydb/core/tx/schemeshard/schemeshard_build_index__create.cpp
index 85a7d215678..7e7ad2af6e5 100644
--- a/ydb/core/tx/schemeshard/schemeshard_build_index__create.cpp
+++ b/ydb/core/tx/schemeshard/schemeshard_build_index__create.cpp
@@ -14,7 +14,7 @@ using namespace NTabletFlatExecutor;
 class TSchemeShard::TIndexBuilder::TTxCreate: public TSchemeShard::TIndexBuilder::TTxSimple<TEvIndexBuilder::TEvCreateRequest, TEvIndexBuilder::TEvCreateResponse> {
 public:
     explicit TTxCreate(TSelf* self, TEvIndexBuilder::TEvCreateRequest::TPtr& ev)
-        : TTxSimple(self, ev, TXTYPE_CREATE_INDEX_BUILD)
+        : TTxSimple(self, TIndexBuildId(ev->Get()->Record.GetTxId()), ev, TXTYPE_CREATE_INDEX_BUILD)
     {}
 
     bool DoExecute(TTransactionContext& txc, const TActorContext& ctx) override {
@@ -24,10 +24,9 @@ public:
 
         Response = MakeHolder<TEvIndexBuilder::TEvCreateResponse>(request.GetTxId());
 
-        const auto id = TIndexBuildId(request.GetTxId());
-        if (Self->IndexBuilds.contains(id)) {
+        if (Self->IndexBuilds.contains(BuildId)) {
             return Reply(Ydb::StatusIds::ALREADY_EXISTS, TStringBuilder()
-                << "Index build with id '" << id << "' already exists");
+                << "Index build with id '" << BuildId << "' already exists");
         }
 
         const TString& uid = GetUid(request.GetOperationParams());
@@ -83,7 +82,7 @@ public:
             }
         }
 
-        TIndexBuildInfo::TPtr buildInfo = new TIndexBuildInfo(id, uid);
+        TIndexBuildInfo::TPtr buildInfo = new TIndexBuildInfo(BuildId, uid);
         buildInfo->DomainPathId = domainPath.Base()->PathId;
         buildInfo->TablePathId = tablePath.Base()->PathId;
 
@@ -198,14 +197,14 @@ public:
 
         Self->PersistBuildIndexState(db, *buildInfo);
 
-        auto [it, emplaced] = Self->IndexBuilds.emplace(id, buildInfo);
+        auto [it, emplaced] = Self->IndexBuilds.emplace(BuildId, buildInfo);
         Y_ASSERT(emplaced);
         if (uid) {
             std::tie(std::ignore, emplaced) = Self->IndexBuildsByUid.emplace(uid, buildInfo);
             Y_ASSERT(emplaced);
         }
 
-        Progress(id);
+        Progress(BuildId);
 
         return true;
     }
diff --git a/ydb/core/tx/schemeshard/schemeshard_build_index__forget.cpp b/ydb/core/tx/schemeshard/schemeshard_build_index__forget.cpp
index f681f79dbd8..ff1a8492729 100644
--- a/ydb/core/tx/schemeshard/schemeshard_build_index__forget.cpp
+++ b/ydb/core/tx/schemeshard/schemeshard_build_index__forget.cpp
@@ -10,7 +10,7 @@ using namespace NTabletFlatExecutor;
 struct TSchemeShard::TIndexBuilder::TTxForget: public TSchemeShard::TIndexBuilder::TTxSimple<TEvIndexBuilder::TEvForgetRequest, TEvIndexBuilder::TEvForgetResponse> {
 public:
     explicit TTxForget(TSelf* self, TEvIndexBuilder::TEvForgetRequest::TPtr& ev)
-        : TTxSimple(self, ev, TXTYPE_FORGET_INDEX_BUILD)
+        : TTxSimple(self, TIndexBuildId(ev->Get()->Record.GetIndexBuildId()), ev, TXTYPE_FORGET_INDEX_BUILD)
     {}
 
     bool DoExecute(TTransactionContext& txc, const TActorContext&) override {
@@ -27,26 +27,25 @@ public:
         }
         const TPathId domainPathId = database.GetPathIdForDomain();
 
-        TIndexBuildId indexBuildId = TIndexBuildId(record.GetIndexBuildId());
-        const auto* indexBuildInfoPtr = Self->IndexBuilds.FindPtr(indexBuildId);
+        const auto* indexBuildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!indexBuildInfoPtr) {
             return Reply(
                 Ydb::StatusIds::NOT_FOUND,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> not found"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> not found"
             );
         }
         const auto& indexBuildInfo = *indexBuildInfoPtr->Get();
         if (indexBuildInfo.DomainPathId != domainPathId) {
             return Reply(
                 Ydb::StatusIds::NOT_FOUND,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> not found in database <" << record.GetDatabaseName() << ">"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> not found in database <" << record.GetDatabaseName() << ">"
             );
         }
 
         if (!indexBuildInfo.IsFinished()) {
             return Reply(
                 Ydb::StatusIds::PRECONDITION_FAILED,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> hasn't been finished yet"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> hasn't been finished yet"
             );
         }
 
diff --git a/ydb/core/tx/schemeshard/schemeshard_build_index__get.cpp b/ydb/core/tx/schemeshard/schemeshard_build_index__get.cpp
index 72af67a620b..16f4007b2bb 100644
--- a/ydb/core/tx/schemeshard/schemeshard_build_index__get.cpp
+++ b/ydb/core/tx/schemeshard/schemeshard_build_index__get.cpp
@@ -11,7 +11,7 @@ using namespace NTabletFlatExecutor;
 struct TSchemeShard::TIndexBuilder::TTxGet: public TSchemeShard::TIndexBuilder::TTxSimple<TEvIndexBuilder::TEvGetRequest, TEvIndexBuilder::TEvGetResponse> {
 public:
     explicit TTxGet(TSelf* self, TEvIndexBuilder::TEvGetRequest::TPtr& ev)
-        : TTxSimple(self, ev, TXTYPE_GET_INDEX_BUILD, false)
+        : TTxSimple(self, TIndexBuildId(ev->Get()->Record.GetIndexBuildId()), ev, TXTYPE_GET_INDEX_BUILD, false)
     {}
 
     bool DoExecute(TTransactionContext&, const TActorContext&) override {
@@ -28,20 +28,18 @@ public:
         }
         const TPathId domainPathId = database.GetPathIdForDomain();
 
-        TIndexBuildId indexBuildId = TIndexBuildId(record.GetIndexBuildId());
-
-        const auto* indexBuildInfoPtr = Self->IndexBuilds.FindPtr(indexBuildId);
+        const auto* indexBuildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!indexBuildInfoPtr) {
             return Reply(
                 Ydb::StatusIds::PRECONDITION_FAILED,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> not found"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> not found"
             );
         }
         const auto& indexBuildInfo = *indexBuildInfoPtr->Get();
         if (indexBuildInfo.DomainPathId != domainPathId) {
             return Reply(
                 Ydb::StatusIds::BAD_REQUEST,
-                TStringBuilder() << "Index build process with id <" << indexBuildId << "> not found in database <" << record.GetDatabaseName() << ">"
+                TStringBuilder() << "Index build process with id <" << BuildId << "> not found in database <" << record.GetDatabaseName() << ">"
             );
         }
 
diff --git a/ydb/core/tx/schemeshard/schemeshard_build_index__list.cpp b/ydb/core/tx/schemeshard/schemeshard_build_index__list.cpp
index 9b1402bcf9a..adef1160159 100644
--- a/ydb/core/tx/schemeshard/schemeshard_build_index__list.cpp
+++ b/ydb/core/tx/schemeshard/schemeshard_build_index__list.cpp
@@ -15,7 +15,7 @@ private:
     static constexpr ui64 DefaultPage = 1;
 public:
     explicit TTxList(TSelf* self, TEvIndexBuilder::TEvListRequest::TPtr& ev)
-        : TTxSimple(self, ev, TXTYPE_LIST_INDEX_BUILD, false)
+        : TTxSimple(self, InvalidIndexBuildId, ev, TXTYPE_LIST_INDEX_BUILD, false)
     {}
 
     bool DoExecute(TTransactionContext&, const TActorContext&) override {
diff --git a/ydb/core/tx/schemeshard/schemeshard_build_index__progress.cpp b/ydb/core/tx/schemeshard/schemeshard_build_index__progress.cpp
index dddcbce4aa2..85f453f6faf 100644
--- a/ydb/core/tx/schemeshard/schemeshard_build_index__progress.cpp
+++ b/ydb/core/tx/schemeshard/schemeshard_build_index__progress.cpp
@@ -51,7 +51,7 @@ protected:
     const NKikimrIndexBuilder::TIndexBuildScanSettings ScanSettings;
 
     const TActorId ResponseActorId;
-    const ui64 BuildIndexId = 0;
+    const TIndexBuildId BuildId;
     TIndexBuildInfo::TSample::TRows Init;
 
     std::shared_ptr<NTxProxy::TUploadTypes> Types;
@@ -70,7 +70,7 @@ public:
                    bool isPostingLevel,
                    const NKikimrIndexBuilder::TIndexBuildScanSettings& scanSettings,
                    const TActorId& responseActorId,
-                   ui64 buildIndexId,
+                   TIndexBuildId buildId,
                    TIndexBuildInfo::TSample::TRows init,
                    NTableIndex::TClusterId parent,
                    NTableIndex::TClusterId child)
@@ -78,13 +78,13 @@ public:
         , IsPostingLevel(isPostingLevel)
         , ScanSettings(scanSettings)
         , ResponseActorId(responseActorId)
-        , BuildIndexId(buildIndexId)
+        , BuildId(buildId)
         , Init(std::move(init))
         , Parent(parent)
         , Child(child)
     {
         LogPrefix = TStringBuilder()
-            << "TUploadSampleK: BuildIndexId: " << BuildIndexId
+            << "TUploadSampleK: BuildIndexId: " << BuildId
             << " ResponseActorId: " << ResponseActorId;
         Y_ENSURE(!Init.empty());
         Y_ENSURE(Parent < Child);
@@ -186,7 +186,7 @@ private:
         }
         TAutoPtr<TEvIndexBuilder::TEvUploadSampleKResponse> response = new TEvIndexBuilder::TEvUploadSampleKResponse;
 
-        response->Record.SetId(BuildIndexId);
+        response->Record.SetId(ui64(BuildId));
         response->Record.SetUploadRows(Rows->size());
         response->Record.SetUploadBytes(RowsBytes);
 
@@ -259,7 +259,7 @@ THolder<TEvSchemeShard::TEvModifySchemeTransaction> CreateIndexPropose(
         modifyScheme.SetOperationType(NKikimrSchemeOp::ESchemeOpCreateColumnBuild);
         buildInfo.SerializeToProto(ss, modifyScheme.MutableInitiateColumnBuild());
     } else {
-        Y_ABORT("Unknown operation kind while building CreateIndexPropose");
+        Y_ENSURE(false, "Unknown operation kind while building CreateIndexPropose");
     }
 
     LOG_DEBUG_S((TlsActivationContext->AsActorContext()), NKikimrServices::BUILD_INDEX, 
@@ -407,7 +407,7 @@ THolder<TEvSchemeShard::TEvModifySchemeTransaction> AlterMainTablePropose(
         TString error;
         if (!ExtractColumnTypeInfo(typeInfo, typeMod, colInfo.DefaultFromLiteral.type(), status, error)) {
             // todo gvit fix that
-            Y_ABORT("failed to extract column type info");
+            Y_ENSURE(false, "failed to extract column type info");
         }
 
         col->SetType(NScheme::TypeName(typeInfo, typeMod));
@@ -510,8 +510,6 @@ using namespace NTabletFlatExecutor;
 
 struct TSchemeShard::TIndexBuilder::TTxProgress: public TSchemeShard::TIndexBuilder::TTxBase  {
 private:
-    TIndexBuildId BuildId;
-
     TMap<TTabletId, THolder<IEventBase>> ToTabletSend;
 
     template <bool WithSnapshot = true, typename Record>
@@ -590,7 +588,7 @@ private:
         ev->Record.SetParent(buildInfo.KMeans.Parent);
         ev->Record.SetChild(buildInfo.KMeans.Child);
 
-        Y_VERIFY_DEBUG(buildInfo.Sample.Rows.size() <= buildInfo.KMeans.K);
+        Y_ENSURE(buildInfo.Sample.Rows.size() <= buildInfo.KMeans.K);
         auto& clusters = *ev->Record.MutableClusters();
         clusters.Reserve(buildInfo.Sample.Rows.size());
         for (const auto& [_, row] : buildInfo.Sample.Rows) {
@@ -760,7 +758,7 @@ private:
         auto path = GetBuildPath(Self, buildInfo, NTableIndex::NTableVectorKmeansTreeIndex::LevelTable);
         Y_ENSURE(buildInfo.Sample.Rows.size() <= buildInfo.KMeans.K);
         auto actor = new TUploadSampleK(path.PathString(), !buildInfo.KMeans.NeedsAnotherLevel(),
-            buildInfo.ScanSettings, Self->SelfId(), ui64(BuildId),
+            buildInfo.ScanSettings, Self->SelfId(), BuildId,
             buildInfo.Sample.Rows, buildInfo.KMeans.Parent, buildInfo.KMeans.Child);
 
         TActivationContext::AsActorContext().MakeFor(Self->SelfId()).Register(actor);
@@ -802,7 +800,7 @@ private:
                 break;
             case NKikimrIndexBuilder::EBuildStatus::BUILD_ERROR:
             case NKikimrIndexBuilder::EBuildStatus::BAD_REQUEST:
-                Y_ABORT("Unreachable");
+                Y_ENSURE(false, "Unreachable");
         }
     }
 
@@ -1113,9 +1111,8 @@ private:
     }
 
 public:
-    explicit TTxProgress(TSelf* self, TIndexBuildId id)
-        : TTxBase(self, TXTYPE_PROGRESS_INDEX_BUILD)
-        , BuildId(id)
+    explicit TTxProgress(TSelf* self, TIndexBuildId buildId)
+        : TTxBase(self, buildId, TXTYPE_PROGRESS_INDEX_BUILD)
     {}
 
     bool DoExecute(TTransactionContext& txc, const TActorContext& ctx) override {
@@ -1128,7 +1125,7 @@ public:
 
         switch (buildInfo.State) {
         case TIndexBuildInfo::EState::Invalid:
-            Y_ABORT("Unreachable");
+            Y_ENSURE(false, "Unreachable");
 
         case TIndexBuildInfo::EState::AlterMainTable:
             if (buildInfo.AlterMainTableTxId == InvalidTxId) {
@@ -1350,6 +1347,32 @@ public:
         return true;
     }
 
+    void OnUnhandledException(TTransactionContext& txc, const TActorContext& ctx, TIndexBuildInfo* buildInfo, const std::exception& exc) override {
+        if (!buildInfo) {
+            LOG_N("TTxBuildProgress: OnUnhandledException: BuildIndexId not found "
+                << (BuildId == InvalidIndexBuildId ? TString("") : TStringBuilder() << ", id# " << BuildId));
+            return;
+        }
+
+        NIceDb::TNiceDb db(txc.DB);
+        if (!buildInfo->Issue.Contains(exc.what())) {
+            buildInfo->Issue += TStringBuilder() << "Unhandled exception " << exc.what();
+        }
+        Self->PersistBuildIndexIssue(db, *buildInfo);
+
+        if (buildInfo->State != TIndexBuildInfo::EState::Filling) {
+            // no idea how to gracefully stop index build otherwise
+            // leave everything as is
+            LOG_E("TTxBuildProgress: OnUnhandledException: not a Filling state, id# " << buildInfo->Id
+                << ", TIndexBuildInfo: " << *buildInfo);
+            return;
+        }
+
+        buildInfo->State = TIndexBuildInfo::EState::Rejection_Applying;
+        Self->PersistBuildIndexState(db, *buildInfo);
+        Self->Execute(Self->CreateTxProgress(buildInfo->Id), ctx);
+    }
+
     static TSerializedTableRange InfiniteRange(ui32 columns) {
         TVector<TCell> vec(columns, TCell());
         TArrayRef<TCell> cells(vec);
@@ -1424,20 +1447,18 @@ ITransaction* TSchemeShard::CreateTxProgress(TIndexBuildId id) {
 
 struct TSchemeShard::TIndexBuilder::TTxBilling: public TSchemeShard::TIndexBuilder::TTxBase  {
 private:
-    TIndexBuildId BuildIndexId;
     TInstant ScheduledAt;
 
 public:
     explicit TTxBilling(TSelf* self, TEvPrivate::TEvIndexBuildingMakeABill::TPtr& ev)
-        : TTxBase(self, TXTYPE_PROGRESS_INDEX_BUILD)
-        , BuildIndexId(ev->Get()->BuildId)
+        : TTxBase(self, TIndexBuildId(ev->Get()->BuildId), TXTYPE_PROGRESS_INDEX_BUILD)
         , ScheduledAt(ev->Get()->SendAt)
     {}
 
     bool DoExecute(TTransactionContext& , const TActorContext& ctx) override {
-        LOG_I("TTxReply : TTxBilling, id# " << BuildIndexId);
+        LOG_I("TTxReply : TTxBilling, id# " << BuildId);
 
-        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildIndexId);
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!buildInfoPtr) {
             return true;
         }
@@ -1456,27 +1477,56 @@ public:
 
     void DoComplete(const TActorContext&) override {
     }
+
+    void OnUnhandledException(TTransactionContext&, const TActorContext&, TIndexBuildInfo*, const std::exception&) override {
+        // seems safe to ignore
+    }
 };
 
 struct TSchemeShard::TIndexBuilder::TTxReply: public TSchemeShard::TIndexBuilder::TTxBase  {
 public:
-    explicit TTxReply(TSelf* self)
-        : TTxBase(self, TXTYPE_PROGRESS_INDEX_BUILD)
+    explicit TTxReply(TSelf* self, TIndexBuildId buildId)
+        : TTxBase(self, buildId, TXTYPE_PROGRESS_INDEX_BUILD)
     {}
 
+    void OnUnhandledException(TTransactionContext& txc, const TActorContext& ctx, TIndexBuildInfo* buildInfo, const std::exception& exc) override {
+        if (!buildInfo) {
+            LOG_E("TTxReply : OnUnhandledException BuildIndexId not found"
+                << (BuildId == InvalidIndexBuildId ? TString("") : TStringBuilder() << ", id# " << BuildId));
+            return;
+        }
+
+        NIceDb::TNiceDb db(txc.DB);
+        if (!buildInfo->Issue.Contains(exc.what())) {
+            buildInfo->Issue += TStringBuilder() << "Unhandled exception " << exc.what();
+        }
+        Self->PersistBuildIndexIssue(db, *buildInfo);
+
+        if (buildInfo->State != TIndexBuildInfo::EState::Filling) {
+            // most replies are used at Filling stage
+            // no idea how to gracefully stop index build otherwise
+            // leave everything as is
+            LOG_E("TTxReply : OnUnhandledException not a Filling state, id# " << buildInfo->Id
+                << ", TIndexBuildInfo: " << *buildInfo);
+            return;
+        }
+
+        buildInfo->State = TIndexBuildInfo::EState::Rejection_Applying;
+        Self->PersistBuildIndexState(db, *buildInfo);
+        Self->Execute(Self->CreateTxProgress(buildInfo->Id), ctx);
+    }
+
     void DoComplete(const TActorContext&) override {
     }
 };
 
 struct TSchemeShard::TIndexBuilder::TTxReplyRetry: public TSchemeShard::TIndexBuilder::TTxReply  {
 private:
-    TIndexBuildId BuildId;
     TTabletId ShardId;
 
 public:
     explicit TTxReplyRetry(TSelf* self, TIndexBuildId buildId, TTabletId shardId)
-        : TTxReply(self)
-        , BuildId(buildId)
+        : TTxReply(self, buildId)
         , ShardId(shardId)
     {}
 
@@ -1526,22 +1576,21 @@ private:
 
 public:
     explicit TTxReplySampleK(TSelf* self, TEvDataShard::TEvSampleKResponse::TPtr& sampleK)
-        : TTxReply(self)
+        : TTxReply(self, TIndexBuildId(sampleK->Get()->Record.GetId()))
         , SampleK(sampleK)
     {
     }
 
     bool DoExecute(TTransactionContext& txc, const TActorContext& ctx) override {
         auto& record = SampleK->Get()->Record;
-        const auto buildId = TIndexBuildId(record.GetId());
         TTabletId shardId = TTabletId(record.GetTabletId());
         TShardIdx shardIdx = Self->GetShardIdx(shardId);
 
-        LOG_N("TTxReply : TEvSampleKResponse, id# " << buildId
+        LOG_N("TTxReply : TEvSampleKResponse, id# " << BuildId
             << ", shardId# " << shardId
             << ", shardIdx# " << shardIdx);
 
-        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(buildId);
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!buildInfoPtr) {
             return true;
         }
@@ -1558,7 +1607,7 @@ public:
         }
 
         if (buildInfo.State != TIndexBuildInfo::EState::Filling) {
-            LOG_I("TTxReply : TEvSampleKResponse superfluous event, id# " << buildId);
+            LOG_I("TTxReply : TEvSampleKResponse superfluous event, id# " << BuildId);
             return true;
         }
 
@@ -1633,16 +1682,16 @@ public:
                 << ", shardIdx: " << shardIdx;
             Self->PersistBuildIndexIssue(db, buildInfo);
             ChangeState(buildInfo.Id, TIndexBuildInfo::EState::Rejection_Applying);
-            Progress(buildId);
+            Progress(BuildId);
             return true;
         case  NKikimrIndexBuilder::EBuildStatus::INVALID:
         case  NKikimrIndexBuilder::EBuildStatus::ACCEPTED:
         case  NKikimrIndexBuilder::EBuildStatus::IN_PROGRESS:
-            Y_ABORT("Unreachable");
+            Y_ENSURE(false, "Unreachable");
         }
-        Self->PersistBuildIndexUploadProgress(db, buildId, shardIdx, shardStatus);
-        Self->IndexBuildPipes.Close(buildId, shardId, ctx);
-        Progress(buildId);
+        Self->PersistBuildIndexUploadProgress(db, BuildId, shardIdx, shardStatus);
+        Self->IndexBuildPipes.Close(BuildId, shardId, ctx);
+        Progress(BuildId);
 
         return true;
     }
@@ -1654,22 +1703,21 @@ private:
 
 public:
     explicit TTxReplyLocalKMeans(TSelf* self, TEvDataShard::TEvLocalKMeansResponse::TPtr& local)
-        : TTxReply(self)
+        : TTxReply(self, TIndexBuildId(local->Get()->Record.GetId()))
         , Local(local)
     {
     }
 
     bool DoExecute(TTransactionContext& txc, const TActorContext& ctx) override {
         const auto& record = Local->Get()->Record;
-        const auto buildId = TIndexBuildId(record.GetId());
         TTabletId shardId = TTabletId(record.GetTabletId());
         TShardIdx shardIdx = Self->GetShardIdx(shardId);
 
-        LOG_N("TTxReply : TEvLocalKMeansResponse, id# " << record.GetId()
+        LOG_N("TTxReply : TEvLocalKMeansResponse, id# " << BuildId
             << ", shardId# " << shardId
             << ", shardIdx# " << shardIdx);
 
-        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(buildId);
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!buildInfoPtr) {
             return true;
         }
@@ -1686,7 +1734,7 @@ public:
         }
 
         if (buildInfo.State != TIndexBuildInfo::EState::Filling) {
-            LOG_I("TTxReply : TEvLocalKMeansResponse superfluous event, id# " << buildId);
+            LOG_I("TTxReply : TEvLocalKMeansResponse superfluous event, id# " << BuildId);
             return true;
         }
 
@@ -1735,16 +1783,16 @@ public:
                 << ", shardIdx: " << shardIdx;
             Self->PersistBuildIndexIssue(db, buildInfo);
             ChangeState(buildInfo.Id, TIndexBuildInfo::EState::Rejection_Applying);
-            Progress(buildId);
+            Progress(BuildId);
             return true;
         case  NKikimrIndexBuilder::EBuildStatus::INVALID:
         case  NKikimrIndexBuilder::EBuildStatus::ACCEPTED:
         case  NKikimrIndexBuilder::EBuildStatus::IN_PROGRESS:
-            Y_ABORT("Unreachable");
+            Y_ENSURE(false, "Unreachable");
         }
-        Self->PersistBuildIndexUploadProgress(db, buildId, shardIdx, shardStatus);
-        Self->IndexBuildPipes.Close(buildId, shardId, ctx);
-        Progress(buildId);
+        Self->PersistBuildIndexUploadProgress(db, BuildId, shardIdx, shardStatus);
+        Self->IndexBuildPipes.Close(BuildId, shardId, ctx);
+        Progress(BuildId);
 
         return true;
     }
@@ -1756,22 +1804,21 @@ private:
 
 public:
     explicit TTxReplyReshuffleKMeans(TSelf* self, TEvDataShard::TEvReshuffleKMeansResponse::TPtr& reshuffle)
-        : TTxReply(self)
+        : TTxReply(self, TIndexBuildId(reshuffle->Get()->Record.GetId()))
         , Reshuffle(reshuffle)
     {
     }
 
     bool DoExecute(TTransactionContext& txc, const TActorContext& ctx) override {
         const auto& record = Reshuffle->Get()->Record;
-        const auto buildId = TIndexBuildId(record.GetId());
         TTabletId shardId = TTabletId(record.GetTabletId());
         TShardIdx shardIdx = Self->GetShardIdx(shardId);
 
-        LOG_N("TTxReply : TEvReshuffleKMeansResponse, id# " << record.GetId()
+        LOG_N("TTxReply : TEvReshuffleKMeansResponse, id# " << BuildId
             << ", shardId# " << shardId
             << ", shardIdx# " << shardIdx);
 
-        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(buildId);
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!buildInfoPtr) {
             return true;
         }
@@ -1788,7 +1835,7 @@ public:
         }
 
         if (buildInfo.State != TIndexBuildInfo::EState::Filling) {
-            LOG_I("TTxReply : TEvReshuffleKMeansResponse superfluous event, id# " << buildId);
+            LOG_I("TTxReply : TEvReshuffleKMeansResponse superfluous event, id# " << BuildId);
             return true;
         }
 
@@ -1837,16 +1884,16 @@ public:
                 << ", shardIdx: " << shardIdx;
             Self->PersistBuildIndexIssue(db, buildInfo);
             ChangeState(buildInfo.Id, TIndexBuildInfo::EState::Rejection_Applying);
-            Progress(buildId);
+            Progress(BuildId);
             return true;
         case  NKikimrIndexBuilder::EBuildStatus::INVALID:
         case  NKikimrIndexBuilder::EBuildStatus::ACCEPTED:
         case  NKikimrIndexBuilder::EBuildStatus::IN_PROGRESS:
-            Y_ABORT("Unreachable");
+            Y_ENSURE(false, "Unreachable");
         }
-        Self->PersistBuildIndexUploadProgress(db, buildId, shardIdx, shardStatus);
-        Self->IndexBuildPipes.Close(buildId, shardId, ctx);
-        Progress(buildId);
+        Self->PersistBuildIndexUploadProgress(db, BuildId, shardIdx, shardStatus);
+        Self->IndexBuildPipes.Close(BuildId, shardId, ctx);
+        Progress(BuildId);
 
         return true;
     }
@@ -1858,22 +1905,21 @@ private:
 
 public:
     explicit TTxReplyPrefixKMeans(TSelf* self, TEvDataShard::TEvPrefixKMeansResponse::TPtr& prefix)
-        : TTxReply(self)
+        : TTxReply(self, TIndexBuildId(prefix->Get()->Record.GetId()))
         , Prefix(prefix)
     {
     }
 
     bool DoExecute(TTransactionContext& txc, const TActorContext& ctx) override {
         const auto& record = Prefix->Get()->Record;
-        const auto buildId = TIndexBuildId(record.GetId());
         TTabletId shardId = TTabletId(record.GetTabletId());
         TShardIdx shardIdx = Self->GetShardIdx(shardId);
 
-        LOG_N("TTxReply : TEvPrefixKMeansResponse, id# " << record.GetId()
+        LOG_N("TTxReply : TEvPrefixKMeansResponse, id# " << BuildId
             << ", shardId# " << shardId
             << ", shardIdx# " << shardIdx);
 
-        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(buildId);
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!buildInfoPtr) {
             return true;
         }
@@ -1890,7 +1936,7 @@ public:
         }
 
         if (buildInfo.State != TIndexBuildInfo::EState::Filling) {
-            LOG_I("TTxReply : TEvPrefixKMeansResponse superfluous event, id# " << buildId);
+            LOG_I("TTxReply : TEvPrefixKMeansResponse superfluous event, id# " << BuildId);
             return true;
         }
 
@@ -1939,16 +1985,16 @@ public:
                 << ", shardIdx: " << shardIdx;
             Self->PersistBuildIndexIssue(db, buildInfo);
             ChangeState(buildInfo.Id, TIndexBuildInfo::EState::Rejection_Applying);
-            Progress(buildId);
+            Progress(BuildId);
             return true;
         case  NKikimrIndexBuilder::EBuildStatus::INVALID:
         case  NKikimrIndexBuilder::EBuildStatus::ACCEPTED:
         case  NKikimrIndexBuilder::EBuildStatus::IN_PROGRESS:
-            Y_ABORT("Unreachable");
+            Y_ENSURE(false, "Unreachable");
         }
-        Self->PersistBuildIndexUploadProgress(db, buildId, shardIdx, shardStatus);
-        Self->IndexBuildPipes.Close(buildId, shardId, ctx);
-        Progress(buildId);
+        Self->PersistBuildIndexUploadProgress(db, BuildId, shardIdx, shardStatus);
+        Self->IndexBuildPipes.Close(BuildId, shardId, ctx);
+        Progress(BuildId);
 
         return true;
     }
@@ -1959,19 +2005,18 @@ private:
     TEvIndexBuilder::TEvUploadSampleKResponse::TPtr UploadSample;
 
 public:
-    explicit TTxReplyUploadSample(TSelf* self, TEvIndexBuilder::TEvUploadSampleKResponse::TPtr& upload)
-        : TTxReply(self)
-        , UploadSample(upload)
+    explicit TTxReplyUploadSample(TSelf* self, TEvIndexBuilder::TEvUploadSampleKResponse::TPtr& uploadSample)
+        : TTxReply(self, TIndexBuildId(uploadSample->Get()->Record.GetId()))
+        , UploadSample(uploadSample)
     {
     }
 
     bool DoExecute([[maybe_unused]] TTransactionContext& txc, [[maybe_unused]] const TActorContext& ctx) override {
         const auto& record = UploadSample->Get()->Record;
-        const auto buildId = TIndexBuildId(record.GetId());
 
-        LOG_N("TTxReply : TEvUploadSampleKResponse, id# " << record.GetId());
+        LOG_N("TTxReply : TEvUploadSampleKResponse, id# " << BuildId);
 
-        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(buildId);
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!buildInfoPtr) {
             return true;
         }
@@ -1983,7 +2028,7 @@ public:
         Y_ENSURE(buildInfo.IsBuildVectorIndex());
 
         if (buildInfo.State != TIndexBuildInfo::EState::Filling) {
-            LOG_I("TTxReply : TEvUploadSampleKResponse superfluous event, id# " << buildId);
+            LOG_I("TTxReply : TEvUploadSampleKResponse superfluous event, id# " << BuildId);
             return true;
         }
         Y_ENSURE(buildInfo.Sample.State == TIndexBuildInfo::TSample::EState::Upload);
@@ -2002,14 +2047,14 @@ public:
         auto status = record.GetUploadStatus();
         if (status == Ydb::StatusIds::SUCCESS) {
             buildInfo.Sample.State = TIndexBuildInfo::TSample::EState::Done;
-            Progress(buildId);
+            Progress(BuildId);
         } else {
             NYql::TIssues issues;
             NYql::IssuesFromMessage(record.GetIssues(), issues);
             buildInfo.Issue += issues.ToString();
             Self->PersistBuildIndexIssue(db, buildInfo);
             ChangeState(buildInfo.Id, TIndexBuildInfo::EState::Rejection_Applying);
-            Progress(buildId);
+            Progress(BuildId);
         }
 
         return true;
@@ -2021,22 +2066,21 @@ private:
     TEvDataShard::TEvBuildIndexProgressResponse::TPtr ShardProgress;
 public:
     explicit TTxReplyProgress(TSelf* self, TEvDataShard::TEvBuildIndexProgressResponse::TPtr& shardProgress)
-        : TTxReply(self)
+        : TTxReply(self, TIndexBuildId(shardProgress->Get()->Record.GetId()))
         , ShardProgress(shardProgress)
     {}
 
 
     bool DoExecute(TTransactionContext& txc, const TActorContext& ctx) override {
         const auto& record = ShardProgress->Get()->Record;
-        const auto buildId = TIndexBuildId(record.GetId());
         TTabletId shardId = TTabletId(record.GetTabletId());
         TShardIdx shardIdx = Self->GetShardIdx(shardId);
 
-        LOG_I("TTxReply : TEvBuildIndexProgressResponse, id# " << record.GetId()
+        LOG_I("TTxReply : TEvBuildIndexProgressResponse, id# " << BuildId
             << ", shardId# " << shardId
             << ", shardIdx# " << shardIdx);
 
-        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(buildId);
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!buildInfoPtr) {
             return true;
         }
@@ -2052,7 +2096,7 @@ public:
         }
 
         if (buildInfo.State != TIndexBuildInfo::EState::Filling) {
-            LOG_I("TTxReply : TEvBuildIndexProgressResponse superfluous event, id# " << buildId);
+            LOG_I("TTxReply : TEvBuildIndexProgressResponse superfluous event, id# " << BuildId);
             return true;
         }
 
@@ -2111,11 +2155,11 @@ public:
 
         switch (shardStatus.Status) {
         case  NKikimrIndexBuilder::EBuildStatus::INVALID:
-            Y_ABORT("Unreachable");
+            Y_ENSURE(false, "Unreachable");
         case  NKikimrIndexBuilder::EBuildStatus::ACCEPTED:
         case  NKikimrIndexBuilder::EBuildStatus::IN_PROGRESS:
             // no oop, wait resolution. Progress key are persisted
-            Self->PersistBuildIndexUploadProgress(db, buildId, shardIdx, shardStatus);
+            Self->PersistBuildIndexUploadProgress(db, BuildId, shardIdx, shardStatus);
             return true;
         case  NKikimrIndexBuilder::EBuildStatus::DONE:
             if (buildInfo.InProgressShards.erase(shardIdx)) {
@@ -2137,12 +2181,12 @@ public:
                 << ", shardIdx: " << shardIdx;
             Self->PersistBuildIndexIssue(db, buildInfo);
             ChangeState(buildInfo.Id, TIndexBuildInfo::EState::Rejection_Applying);
-            Progress(buildId);
+            Progress(BuildId);
             return true;
         }
-        Self->PersistBuildIndexUploadProgress(db, buildId, shardIdx, shardStatus);
-        Self->IndexBuildPipes.Close(buildId, shardId, ctx);
-        Progress(buildId);
+        Self->PersistBuildIndexUploadProgress(db, BuildId, shardIdx, shardStatus);
+        Self->IndexBuildPipes.Close(BuildId, shardId, ctx);
+        Progress(BuildId);
 
         return true;
     }
@@ -2153,7 +2197,7 @@ private:
     TTxId CompletedTxId;
 public:
     explicit TTxReplyCompleted(TSelf* self, TTxId completedTxId)
-        : TTxReply(self)
+        : TTxReply(self, InvalidIndexBuildId)
         , CompletedTxId(completedTxId)
     {}
 
@@ -2168,9 +2212,9 @@ public:
             return true;
         }
 
-        const auto buildId = *buildIdPtr;
-        auto& buildInfo = *Self->IndexBuilds.at(buildId);
-        LOG_I("TTxReply : TEvNotifyTxCompletionResult, id# " << buildId
+        BuildId = *buildIdPtr;
+        auto& buildInfo = *Self->IndexBuilds.at(BuildId);
+        LOG_I("TTxReply : TEvNotifyTxCompletionResult, id# " << BuildId
             << ", txId# " << txId);
         LOG_D("TTxReply : TEvNotifyTxCompletionResult"
             << ", TIndexBuildInfo: " << buildInfo
@@ -2235,7 +2279,7 @@ public:
             Y_ENSURE(false, "Unreachable " << state);
         }
 
-        Progress(buildId);
+        Progress(BuildId);
 
         return true;
     }
@@ -2246,7 +2290,7 @@ private:
     TEvSchemeShard::TEvModifySchemeTransactionResult::TPtr ModifyResult;
 public:
     explicit TTxReplyModify(TSelf* self, TEvSchemeShard::TEvModifySchemeTransactionResult::TPtr& modifyResult)
-        : TTxReply(self)
+        : TTxReply(self, InvalidIndexBuildId)
         , ModifyResult(modifyResult)
     {}
 
@@ -2287,11 +2331,11 @@ public:
             return true;
         }
 
-        const auto buildId = *buildIdPtr;
+        BuildId = *buildIdPtr;
         // We need this because we use buildInfo after EraseBuildInfo
-        auto buildInfoPin = Self->IndexBuilds.at(buildId);
+        auto buildInfoPin = Self->IndexBuilds.at(BuildId);
         auto& buildInfo = *buildInfoPin;
-        LOG_I("TTxReply : TEvModifySchemeTransactionResult, id# " << buildId
+        LOG_I("TTxReply : TEvModifySchemeTransactionResult, id# " << BuildId
             << ", cookie: " << ModifyResult->Cookie
             << ", record: " << record.ShortDebugString()
             << ", status: " << NKikimrScheme::EStatus_Name(record.GetStatus()));
@@ -2324,7 +2368,7 @@ public:
             if (record.GetStatus() == NKikimrScheme::StatusAccepted) {
                 // no op
             } else if (record.GetStatus() == NKikimrScheme::StatusAlreadyExists) {
-                Y_ABORT("NEED MORE TESTING");
+                Y_ENSURE(false, "NEED MORE TESTING");
                 // no op
             } else {
                 buildInfo.Issue += TStringBuilder()
@@ -2430,7 +2474,7 @@ public:
             Y_ENSURE(false, "Unreachable " << state);
         }
 
-        Progress(buildId);
+        Progress(BuildId);
 
         return true;
     }
@@ -2441,15 +2485,14 @@ private:
     TEvTxAllocatorClient::TEvAllocateResult::TPtr AllocateResult;
 public:
     explicit TTxReplyAllocate(TSelf* self, TEvTxAllocatorClient::TEvAllocateResult::TPtr& allocateResult)
-        : TTxReply(self)
+        : TTxReply(self, TIndexBuildId(allocateResult->Cookie))
         , AllocateResult(allocateResult)
     {}
 
     bool DoExecute(TTransactionContext& txc,[[maybe_unused]] const TActorContext& ctx) override {
-        TIndexBuildId buildId = TIndexBuildId(AllocateResult->Cookie);
         const auto txId = TTxId(AllocateResult->Get()->TxIds.front());
 
-        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(buildId);
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
         if (!buildInfoPtr) {
             LOG_I("TTxReply : TEvAllocateResult superfluous message"
                 << ", cookie: " << AllocateResult->Cookie
@@ -2459,7 +2502,7 @@ public:
         }
 
         auto& buildInfo = *buildInfoPtr->Get();
-        LOG_I("TTxReply : TEvAllocateResult, id# " << buildId
+        LOG_I("TTxReply : TEvAllocateResult, id# " << BuildId
             << ", txId# " << txId);
         LOG_D("TTxReply : TEvAllocateResult"
             << ", TIndexBuildInfo: " << buildInfo
@@ -2515,7 +2558,7 @@ public:
             Y_ENSURE(false, "Unreachable " << state);
         }
 
-        Progress(buildId);
+        Progress(BuildId);
 
         return true;
     }
diff --git a/ydb/core/tx/schemeshard/schemeshard_build_index_tx_base.cpp b/ydb/core/tx/schemeshard/schemeshard_build_index_tx_base.cpp
index eb84bb449a2..647c7b8e44e 100644
--- a/ydb/core/tx/schemeshard/schemeshard_build_index_tx_base.cpp
+++ b/ydb/core/tx/schemeshard/schemeshard_build_index_tx_base.cpp
@@ -428,7 +428,18 @@ bool TSchemeShard::TIndexBuilder::TTxBase::GotScheduledBilling(TIndexBuildInfo&
 }
 
 bool TSchemeShard::TIndexBuilder::TTxBase::Execute(TTransactionContext& txc, const TActorContext& ctx) {
-    if (!DoExecute(txc, ctx)) {
+    bool executeResult;
+
+    try {
+        executeResult = DoExecute(txc, ctx);
+    } catch (const std::exception& exc) {
+        if (OnUnhandledExceptionSafe(txc, ctx, exc)) {
+            return true;
+        }
+        throw; // fail process, a really bad thing has happened
+    }
+
+    if (!executeResult) {
         return false;
     }
 
@@ -436,6 +447,30 @@ bool TSchemeShard::TIndexBuilder::TTxBase::Execute(TTransactionContext& txc, con
     return true;
 }
 
+bool TSchemeShard::TIndexBuilder::TTxBase::OnUnhandledExceptionSafe(TTransactionContext& txc, const TActorContext& ctx, const std::exception& originalExc) {
+    try {
+        const auto* buildInfoPtr = Self->IndexBuilds.FindPtr(BuildId);
+        TIndexBuildInfo* buildInfo = buildInfoPtr
+            ? buildInfoPtr->Get()
+            : nullptr;
+
+        LOG_E("Unhandled exception, id#"
+            << (BuildId == InvalidIndexBuildId ? TString("<no id>") : TStringBuilder() << BuildId)
+            << " " << TypeName(originalExc) << ": " << originalExc.what() << Endl
+            << TBackTrace::FromCurrentException().PrintToString()
+            << ", TIndexBuildInfo: " << (buildInfo ? TStringBuilder() << (*buildInfo) : TString("<no build info>")));
+
+        OnUnhandledException(txc, ctx, buildInfo, originalExc);
+
+        return true;
+    } catch (const std::exception& handleExc) {
+        LOG_E("OnUnhandledException throws unhandled exception " 
+            << TypeName(handleExc) << ": " << handleExc.what() << Endl
+            << TBackTrace::FromCurrentException().PrintToString());
+        return false;
+    }
+}
+
 void TSchemeShard::TIndexBuilder::TTxBase::Complete(const TActorContext& ctx) {
     DoComplete(ctx);
 
diff --git a/ydb/core/tx/schemeshard/schemeshard_build_index_tx_base.h b/ydb/core/tx/schemeshard/schemeshard_build_index_tx_base.h
index 02f96b34aef..52d63138167 100644
--- a/ydb/core/tx/schemeshard/schemeshard_build_index_tx_base.h
+++ b/ydb/core/tx/schemeshard/schemeshard_build_index_tx_base.h
@@ -11,6 +11,9 @@ namespace NSchemeShard {
 class TSchemeShard::TIndexBuilder::TTxBase: public NTabletFlatExecutor::TTransactionBase<TSchemeShard> {
 private:
     TSideEffects SideEffects;
+protected:
+    TIndexBuildId BuildId;
+private:
     const NKikimr::NSchemeShard::ETxTypes TxType;
 public:
     const TString LogPrefix;
@@ -29,6 +32,7 @@ private:
     ui64 RequestUnits(const TBillingStats& stats);
     void RoundPeriod(TInstant& start, TInstant& end);
     void ApplyBill(NTabletFlatExecutor::TTransactionContext& txc, const TActorContext& ctx);
+    bool OnUnhandledExceptionSafe(TTransactionContext& txc, const TActorContext& ctx, const std::exception& exc);
 
 protected:
     void Send(TActorId dst, THolder<IEventBase> message, ui32 flags = 0, ui64 cookie = 0);
@@ -48,8 +52,9 @@ protected:
     bool GotScheduledBilling(TIndexBuildInfo& indexBuildInfo);
 
 public:
-    explicit TTxBase(TSelf* self, NKikimr::NSchemeShard::ETxTypes txType)
+    explicit TTxBase(TSelf* self, TIndexBuildId buildId, NKikimr::NSchemeShard::ETxTypes txType)
         : TBase(self)
+        , BuildId(buildId)
         , TxType(txType)
         , LogPrefix(TStringBuilder() << "TIndexBuilder::" << NKikimr::NSchemeShard::ETxTypes_Name(txType) << ": ")
     { }
@@ -60,6 +65,7 @@ public:
 
     virtual bool DoExecute(TTransactionContext& txc, const TActorContext& ctx) = 0;
     virtual void DoComplete(const TActorContext& ctx) = 0;
+    virtual void OnUnhandledException(TTransactionContext& txc, const TActorContext& ctx, TIndexBuildInfo* buildInfo, const std::exception& exc) = 0;
 
     bool Execute(TTransactionContext& txc, const TActorContext& ctx) override;
     void Complete(const TActorContext& ctx) override;
@@ -72,12 +78,17 @@ public:
     THolder<TResponse> Response;
     const bool IsMutableOperation;
 
-    explicit TTxSimple(TSelf* self, typename TRequest::TPtr& ev, NKikimr::NSchemeShard::ETxTypes txType, bool isMutableOperation = true)
-        : TTxBase(self, txType)
+    explicit TTxSimple(TSelf* self, TIndexBuildId buildId, typename TRequest::TPtr& ev, NKikimr::NSchemeShard::ETxTypes txType, bool isMutableOperation = true)
+        : TTxBase(self, buildId, txType)
         , Request(ev)
         , IsMutableOperation(isMutableOperation)
     { }
 
+    void OnUnhandledException(TTransactionContext&, const TActorContext&, TIndexBuildInfo*, const std::exception& exc) override {
+        Reply(Ydb::StatusIds::INTERNAL_ERROR, TStringBuilder()
+            << "Unhandled exception " << exc.what());
+    }
+
     bool Reply(const Ydb::StatusIds::StatusCode status = Ydb::StatusIds::SUCCESS, const TString& errorMessage = TString())
     {
         Y_ABORT_UNLESS(Response);
diff --git a/ydb/core/tx/schemeshard/ut_index_build/ut_vector_index_build.cpp b/ydb/core/tx/schemeshard/ut_index_build/ut_vector_index_build.cpp
index 8bae31a12a1..49e2b911029 100644
--- a/ydb/core/tx/schemeshard/ut_index_build/ut_vector_index_build.cpp
+++ b/ydb/core/tx/schemeshard/ut_index_build/ut_vector_index_build.cpp
@@ -419,4 +419,151 @@ Y_UNIT_TEST_SUITE (VectorIndexBuildTest) {
             });
         }
     }
+
+    Y_UNIT_TEST(TTxReply_DoExecute_Throws) {
+        TTestBasicRuntime runtime;
+        TTestEnv env(runtime);
+        ui64 txId = 100;
+
+        runtime.SetLogPriority(NKikimrServices::TX_DATASHARD, NLog::PRI_TRACE);
+        runtime.SetLogPriority(NKikimrServices::BUILD_INDEX, NLog::PRI_TRACE);
+
+        TestCreateTable(runtime, ++txId, "/MyRoot", R"(
+            Name: "vectors"
+            Columns { Name: "id" Type: "Uint64" }
+            Columns { Name: "embedding" Type: "String" }
+            KeyColumnNames: [ "id" ]
+        )");
+        env.TestWaitNotification(runtime, txId);
+
+        NYdb::NTable::TGlobalIndexSettings globalIndexSettings;
+
+        std::unique_ptr<NYdb::NTable::TKMeansTreeSettings> kmeansTreeSettings;
+        {
+            Ydb::Table::KMeansTreeSettings proto;
+            UNIT_ASSERT(google::protobuf::TextFormat::ParseFromString(R"(
+                settings {
+                    metric: DISTANCE_COSINE
+                    vector_type: VECTOR_TYPE_FLOAT
+                    vector_dimension: 1024
+                }
+                levels: 5
+                clusters: 4
+            )", &proto));
+            using T = NYdb::NTable::TKMeansTreeSettings;
+            kmeansTreeSettings = std::make_unique<T>(T::FromProto(proto));
+        }
+
+        TBlockEvents<TEvDataShard::TEvLocalKMeansResponse> blocked(runtime, [&](auto& ev) {
+            ev->Get()->Record.SetRequestSeqNoRound(999);
+            return true;
+        });
+
+        const ui64 buildIndexTx = ++txId;
+        const TVector<TString> dataColumns;
+        const TVector<TString> indexColumns{"embedding"};
+        AsyncBuildVectorIndex(runtime, buildIndexTx, TTestTxConfig::SchemeShard, "/MyRoot", "/MyRoot/vectors", "index1", "embedding");
+
+        runtime.WaitFor("block", [&]{ return blocked.size(); });
+        blocked.Stop().Unblock();
+
+        env.TestWaitNotification(runtime, buildIndexTx);
+
+        {
+            auto buildIndexOperation = TestGetBuildIndex(runtime, TTestTxConfig::SchemeShard, "/MyRoot", buildIndexTx);
+            UNIT_ASSERT_VALUES_EQUAL_C(
+                buildIndexOperation.GetIndexBuild().GetState(), Ydb::Table::IndexBuildState::STATE_REJECTED,
+                buildIndexOperation.DebugString()
+            );
+            UNIT_ASSERT_STRING_CONTAINS(buildIndexOperation.DebugString(), "Condition violated: `actualSeqNo > recordSeqNo");
+        }
+
+        RebootTablet(runtime, TTestTxConfig::SchemeShard, runtime.AllocateEdgeActor());
+
+        {
+            auto buildIndexOperation = TestGetBuildIndex(runtime, TTestTxConfig::SchemeShard, "/MyRoot", buildIndexTx);
+            UNIT_ASSERT_VALUES_EQUAL_C(
+                buildIndexOperation.GetIndexBuild().GetState(), Ydb::Table::IndexBuildState::STATE_REJECTED,
+                buildIndexOperation.DebugString()
+            );
+            UNIT_ASSERT_STRING_CONTAINS(buildIndexOperation.DebugString(), "Unhandled exception");
+            UNIT_ASSERT_STRING_CONTAINS(buildIndexOperation.DebugString(), "Condition violated: `actualSeqNo > recordSeqNo");
+        }
+    }
+
+    Y_UNIT_TEST(TTxProgress_Throws) {
+        TTestBasicRuntime runtime;
+        TTestEnv env(runtime);
+        ui64 txId = 100;
+
+        runtime.SetLogPriority(NKikimrServices::TX_DATASHARD, NLog::PRI_TRACE);
+        runtime.SetLogPriority(NKikimrServices::BUILD_INDEX, NLog::PRI_TRACE);
+
+        TestCreateTable(runtime, ++txId, "/MyRoot", R"(
+            Name: "vectors"
+            Columns { Name: "id" Type: "Uint64" }
+            Columns { Name: "embedding" Type: "String" }
+            KeyColumnNames: [ "id" ]
+        )");
+        env.TestWaitNotification(runtime, txId);
+
+        NYdb::NTable::TGlobalIndexSettings globalIndexSettings;
+
+        std::unique_ptr<NYdb::NTable::TKMeansTreeSettings> kmeansTreeSettings;
+        {
+            Ydb::Table::KMeansTreeSettings proto;
+            UNIT_ASSERT(google::protobuf::TextFormat::ParseFromString(R"(
+                settings {
+                    metric: DISTANCE_COSINE
+                    vector_type: VECTOR_TYPE_FLOAT
+                    vector_dimension: 1024
+                }
+                levels: 5
+                clusters: 4
+            )", &proto));
+            using T = NYdb::NTable::TKMeansTreeSettings;
+            kmeansTreeSettings = std::make_unique<T>(T::FromProto(proto));
+        }
+
+        const ui64 buildIndexTx = ++txId;
+        const TVector<TString> dataColumns;
+        const TVector<TString> indexColumns{"embedding"};
+        AsyncBuildVectorIndex(runtime, buildIndexTx, TTestTxConfig::SchemeShard, "/MyRoot", "/MyRoot/vectors", "index1", "embedding");
+
+        env.TestWaitNotification(runtime, buildIndexTx);
+
+        {
+            auto buildIndexOperation = TestGetBuildIndex(runtime, TTestTxConfig::SchemeShard, "/MyRoot", buildIndexTx);
+            UNIT_ASSERT_VALUES_EQUAL_C(
+                buildIndexOperation.GetIndexBuild().GetState(), Ydb::Table::IndexBuildState::STATE_DONE,
+                buildIndexOperation.DebugString()
+            );
+        }
+
+        { // set 'Invalid' state
+            TString writeQuery = Sprintf(R"(
+                (
+                    (let key '( '('Id (Uint64 '%lu)) ) )
+                    (let value '('('State (Uint32 '0)) ) )
+                    (return (AsList (UpdateRow 'IndexBuild key value) ))
+                )
+            )", buildIndexTx);
+            NKikimrMiniKQL::TResult result;
+            TString err;
+            NKikimrProto::EReplyStatus status = LocalMiniKQL(runtime, TTestTxConfig::SchemeShard, writeQuery, result, err);
+            UNIT_ASSERT_VALUES_EQUAL_C(status, NKikimrProto::EReplyStatus::OK, err);
+        }
+
+        RebootTablet(runtime, TTestTxConfig::SchemeShard, runtime.AllocateEdgeActor());
+
+        {
+            auto buildIndexOperation = TestGetBuildIndex(runtime, TTestTxConfig::SchemeShard, "/MyRoot", buildIndexTx);
+            UNIT_ASSERT_VALUES_EQUAL_C(
+                buildIndexOperation.GetIndexBuild().GetState(), Ydb::Table::IndexBuildState::STATE_UNSPECIFIED,
+                buildIndexOperation.DebugString()
+            );
+            UNIT_ASSERT_STRING_CONTAINS(buildIndexOperation.DebugString(), "Unhandled exception");
+            UNIT_ASSERT_STRING_CONTAINS(buildIndexOperation.DebugString(), "Unreachable");
+        }
+    }
 }