YQ-3975 RD fixed fault for parsing errors without filter (#12707)

11 files changed, 96 insertions, 76 deletions

diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/filters/filters_set.cpp b/ydb/core/fq/libs/row_dispatcher/format_handler/filters/filters_set.cpp
index 6065579185..ae88416712 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/filters/filters_set.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/filters/filters_set.cpp
@@ -154,16 +154,7 @@ public:
                 continue;
             }
 
-            if (filterHandler.GetPurecalcFilter()) {
-                PushToFilter(filterHandler, offsets, columnIndex, values, numberRows);
-                continue;
-            }
-
-            // Clients without filters
-            LOG_ROW_DISPATCHER_TRACE("Add " << numberRows << " rows to client " << consumer->GetFilterId() << " without filtering");
-            for (ui64 rowId = 0; rowId < numberRows; ++rowId) {
-                consumer->OnFilteredData(rowId);
-            }
+            PushToFilter(filterHandler, offsets, columnIndex, values, numberRows);
         }
         Stats.AddFilterLatency(TInstant::Now() - startFilter);
     }
@@ -193,7 +184,9 @@ public:
         LOG_ROW_DISPATCHER_TRACE("Create filter with id " << filter->GetFilterId());
 
         IPurecalcFilter::TPtr purecalcFilter;
-        if (filter->GetWhereFilter()) {
+        if (const auto& predicate = filter->GetWhereFilter()) {
+            LOG_ROW_DISPATCHER_TRACE("Create purecalc filter for predicate '" << predicate << "' (filter id: " << filter->GetFilterId() << ")");
+
             auto filterStatus = CreatePurecalcFilter(filter);
             if (filterStatus.IsFail()) {
                 return filterStatus;
@@ -225,9 +218,6 @@ public:
 
 private:
     void PushToFilter(const TFilterHandler& filterHandler, const TVector<ui64>& offsets, const TVector<ui64>& columnIndex, const TVector<const TVector<NYql::NUdf::TUnboxedValue>*>& values, ui64 numberRows) {
-        const auto filter = filterHandler.GetPurecalcFilter();
-        Y_ENSURE(filter, "Expected initialized filter");
-
         const auto consumer = filterHandler.GetConsumer();
         const auto& columnIds = consumer->GetColumnIds();
 
@@ -246,8 +236,13 @@ private:
             }
         }
 
-        LOG_ROW_DISPATCHER_TRACE("Pass " << numberRows << " rows to purecalc filter (client id: " << consumer->GetFilterId() << ")");
-        filter->FilterData(result, numberRows);
+        if (const auto filter = filterHandler.GetPurecalcFilter()) {
+            LOG_ROW_DISPATCHER_TRACE("Pass " << numberRows << " rows to purecalc filter (filter id: " << consumer->GetFilterId() << ")");
+            filter->FilterData(result, numberRows);
+        } else if (numberRows) {
+            LOG_ROW_DISPATCHER_TRACE("Add " << numberRows << " rows to client " << consumer->GetFilterId() << " without filtering");
+            consumer->OnFilteredBatch(0, numberRows - 1);
+        }
     }
 
 private:
diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/filters/filters_set.h b/ydb/core/fq/libs/row_dispatcher/format_handler/filters/filters_set.h
index 427e73fa53..57da103b1a 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/filters/filters_set.h
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/filters/filters_set.h
@@ -17,6 +17,8 @@ public:
     virtual const TVector<ui64>& GetColumnIds() const = 0;
     virtual TMaybe<ui64> GetNextMessageOffset() const = 0;
 
+    virtual void OnFilteredBatch(ui64 firstRow, ui64 lastRow) = 0;  // inclusive interval [firstRow, lastRow]
+
     virtual void OnFilterStarted() = 0;
     virtual void OnFilteringError(TStatus status) = 0;
 };
diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/format_handler.cpp b/ydb/core/fq/libs/row_dispatcher/format_handler/format_handler.cpp
index df46b12bef..f492e864b3 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/format_handler.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/format_handler.cpp
@@ -207,6 +207,13 @@ class TTopicFormatHandler : public NActors::TActor<TTopicFormatHandler>, public
             Client->StartClientSession();
         }
 
+        void OnFilteredBatch(ui64 firstRow, ui64 lastRow) override {
+            LOG_ROW_DISPATCHER_TRACE("OnFilteredBatch, rows [" << firstRow << ", " << lastRow << "]");
+            for (ui64 rowId = firstRow; rowId <= lastRow; ++rowId) {
+                OnFilteredData(rowId);
+            }
+        }
+
         void OnFilteredData(ui64 rowId) override {
             const ui64 offset = Self.Offsets->at(rowId);
             if (const auto nextOffset = Client->GetNextMessageOffset(); nextOffset && offset < *nextOffset) {
diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/parsers/json_parser.cpp b/ydb/core/fq/libs/row_dispatcher/format_handler/parsers/json_parser.cpp
index 7c4fb95102..46c0196a66 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/parsers/json_parser.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/parsers/json_parser.cpp
@@ -414,23 +414,23 @@ protected:
 
         simdjson::ondemand::document_stream documents;
         CHECK_JSON_ERROR(Parser.iterate_many(values, size, simdjson::ondemand::DEFAULT_BATCH_SIZE).get(documents)) {
-            return TStatus::Fail(EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse message batch from offset " << Buffer.Offsets.front() << ", json documents was corrupted: " << simdjson::error_message(error));
+            return TStatus::Fail(EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse message batch from offset " << Buffer.Offsets.front() << ", json documents was corrupted: " << simdjson::error_message(error) << " Current data batch: " << TruncateString(std::string_view(values, size)));
         }
 
         size_t rowId = 0;
         for (auto document : documents) {
             if (Y_UNLIKELY(rowId >= Buffer.NumberValues)) {
-                return TStatus::Fail(EStatusId::INTERNAL_ERROR, TStringBuilder() << "Failed to parse json messages, expected " << Buffer.NumberValues << " json rows from offset " << Buffer.Offsets.front() << " but got " << rowId + 1);
+                return TStatus::Fail(EStatusId::INTERNAL_ERROR, TStringBuilder() << "Failed to parse json messages, expected " << Buffer.NumberValues << " json rows from offset " << Buffer.Offsets.front() << " but got " << rowId + 1 << " (expected one json row for each offset from topic API in json each row format, maybe initial data was corrupted or messages is not in json format), current data batch: " << TruncateString(std::string_view(values, size)));
             }
 
             const ui64 offset = Buffer.Offsets[rowId];
             CHECK_JSON_ERROR(document.error()) {
-                return TStatus::Fail(EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse json message for offset " << offset << ", json document was corrupted: " << simdjson::error_message(error));
+                return TStatus::Fail(EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse json message for offset " << offset << ", json document was corrupted: " << simdjson::error_message(error) << " Current data batch: " << TruncateString(std::string_view(values, size)));
             }
 
             for (auto item : document.get_object()) {
                 CHECK_JSON_ERROR(item.error()) {
-                    return TStatus::Fail(EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse json message for offset " << offset << ", json item was corrupted: " << simdjson::error_message(error));
+                    return TStatus::Fail(EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse json message for offset " << offset << ", json item was corrupted: " << simdjson::error_message(error) << " Current data batch: " << TruncateString(std::string_view(values, size)));
                 }
 
                 const auto it = ColumnsIndex.find(item.escaped_key().value());
@@ -445,7 +445,7 @@ protected:
         }
 
         if (Y_UNLIKELY(rowId != Buffer.NumberValues)) {
-            return TStatus::Fail(EStatusId::INTERNAL_ERROR, TStringBuilder() << "Failed to parse json messages, expected " << Buffer.NumberValues << " json rows from offset " << Buffer.Offsets.front() << " but got " << rowId);
+            return TStatus::Fail(EStatusId::INTERNAL_ERROR, TStringBuilder() << "Failed to parse json messages, expected " << Buffer.NumberValues << " json rows from offset " << Buffer.Offsets.front() << " but got " << rowId << " (expected one json row for each offset from topic API in json each row format, maybe initial data was corrupted or messages is not in json format), current data batch: " << TruncateString(std::string_view(values, size)));
         }
 
         const ui64 firstOffset = Buffer.Offsets.front();
diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/common/ut_common.cpp b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/common/ut_common.cpp
index b65911e793..f7f3489dd5 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/common/ut_common.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/common/ut_common.cpp
@@ -68,6 +68,7 @@ public:
 
     void Validate(const NYql::NUdf::TUnboxedValue& parsedValue) const override {
         if (!parsedValue) {
+            UNIT_FAIL("Unexpected NULL value for optional cell");
             return;
         }
         Value->Validate(parsedValue.GetOptionalValue());
@@ -166,7 +167,7 @@ void TBaseFixture::SetUp(NUnitTest::TTestContext&) {
     TAutoPtr<NKikimr::TAppPrepare> app = new NKikimr::TAppPrepare();
     Runtime.SetLogBackend(NActors::CreateStderrBackend());
     Runtime.SetLogPriority(NKikimrServices::FQ_ROW_DISPATCHER, NActors::NLog::PRI_TRACE);
-    Runtime.SetDispatchTimeout(TDuration::Seconds(5));
+    Runtime.SetDispatchTimeout(WAIT_TIMEOUT);
     Runtime.Initialize(app->Unwrap());
 
     // Init tls context
diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/common/ut_common.h b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/common/ut_common.h
index dd1c3d1c9f..ce54150b46 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/common/ut_common.h
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/common/ut_common.h
@@ -10,6 +10,8 @@
 
 namespace NFq::NRowDispatcher::NTests {
 
+static constexpr TDuration WAIT_TIMEOUT = TDuration::Seconds(20);
+
 class TBaseFixture : public NUnitTest::TBaseFixture, public TTypeParser {
 public:
     // Helper classes for checking serialized rows in multi type format
diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/format_handler_ut.cpp b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/format_handler_ut.cpp
index c643dba270..75daa83bc5 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/format_handler_ut.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/format_handler_ut.cpp
@@ -155,7 +155,7 @@ public:
         FormatHandler = CreateTestFormatHandler(config, settings);
     }
 
-    TStatus MakeClient(const TVector<TSchemaColumn>& columns, const TString& whereFilter, TCallback callback, ui64 expectedFilteredRows = 1) {
+    [[nodiscard]] TStatus MakeClient(const TVector<TSchemaColumn>& columns, const TString& whereFilter, TCallback callback, ui64 expectedFilteredRows = 1) {
         ClientIds.emplace_back(ClientIds.size(), 0, 0, 0);
 
         auto client = MakeIntrusive<TClientDataConsumer>(ClientIds.back(), columns, whereFilter, callback, expectedFilteredRows);
@@ -202,6 +202,30 @@ public:
         FormatHandler->RemoveClient(clientId);
     }
 
+public:
+    static TCallback EmptyCheck() {
+        return [&](TQueue<std::pair<TRope, TVector<ui64>>>&& data) {};
+    }
+
+    static TCallback OneBatchCheck(std::function<void(TRope&& messages, TVector<ui64>&& offsets)> callback) {
+        return [callback](TQueue<std::pair<TRope, TVector<ui64>>>&& data) {
+            UNIT_ASSERT_VALUES_EQUAL(data.size(), 1);
+            auto [messages, offsets] = data.front();
+
+            UNIT_ASSERT(!offsets.empty());
+            callback(std::move(messages), std::move(offsets));
+        };
+    }
+
+    TCallback OneRowCheck(ui64 offset, const TRow& row) const {
+        return OneBatchCheck([this, offset, row](TRope&& messages, TVector<ui64>&& offsets) {
+            UNIT_ASSERT_VALUES_EQUAL(offsets.size(), 1);
+            UNIT_ASSERT_VALUES_EQUAL(offsets.front(), offset);
+
+            CheckMessageBatch(messages, TBatch().AddRow(row));
+        });
+    }
+
 private:
     void ExtractClientsData() {
         for (auto& client : Clients) {
@@ -233,33 +257,13 @@ Y_UNIT_TEST_SUITE(TestFormatHandler) {
         CheckSuccess(MakeClient(
             {commonColumn, {"col_first", "[DataType; String]"}},
             "WHERE col_first = \"str_first__large__\"",
-            [&](TQueue<std::pair<TRope, TVector<ui64>>>&& data) {
-                UNIT_ASSERT_VALUES_EQUAL(data.size(), 1);
-
-                auto [messages, offsets] = data.front();
-                UNIT_ASSERT_VALUES_EQUAL(offsets.size(), 1);
-                UNIT_ASSERT_VALUES_EQUAL(offsets.front(), firstOffset + 1);
-
-                CheckMessageBatch(messages, TBatch().AddRow(
-                    TRow().AddString("event2").AddString("str_first__large__")
-                ));
-            }
+            OneRowCheck(firstOffset + 1, TRow().AddString("event2").AddString("str_first__large__"))
         ));
 
         CheckSuccess(MakeClient(
             {commonColumn, {"col_second", "[DataType; String]"}},
             "WHERE col_second = \"str_second\"",
-            [&](TQueue<std::pair<TRope, TVector<ui64>>>&& data) {
-                UNIT_ASSERT_VALUES_EQUAL(data.size(), 1);
-
-                auto [messages, offsets] = data.front();
-                UNIT_ASSERT_VALUES_EQUAL(offsets.size(), 1);
-                UNIT_ASSERT_VALUES_EQUAL(offsets.front(), firstOffset);
-
-                CheckMessageBatch(messages, TBatch().AddRow(
-                    TRow().AddString("event1").AddString("str_second")
-                ));
-            }
+            OneRowCheck(firstOffset, TRow().AddString("event1").AddString("str_second"))
         ));
 
         ParseMessages({
@@ -288,14 +292,10 @@ Y_UNIT_TEST_SUITE(TestFormatHandler) {
             R"({"col_a": false, "col_b": {"X": "Y"}})"
         };
 
-        CheckSuccess(MakeClient(schema, "WHERE FALSE", [&](TQueue<std::pair<TRope, TVector<ui64>>>&&) {}, 0));
-
-        auto trueChacker = [&](TQueue<std::pair<TRope, TVector<ui64>>>&& data) {
-            UNIT_ASSERT_VALUES_EQUAL(data.size(), 1);
-            auto [messages, offsets] = data.front();
+        CheckSuccess(MakeClient(schema, "WHERE FALSE", EmptyCheck(), 0));
 
+        const auto trueChacker = OneBatchCheck([&](TRope&& messages, TVector<ui64>&& offsets) {
             TBatch expectedBatch;
-            UNIT_ASSERT(!offsets.empty());
             for (ui64 offset : offsets) {
                 UNIT_ASSERT(offset - firstOffset < testData.size());
                 expectedBatch.AddRow(
@@ -304,7 +304,7 @@ Y_UNIT_TEST_SUITE(TestFormatHandler) {
             }
 
             CheckMessageBatch(messages, expectedBatch);
-        };
+        });
         CheckSuccess(MakeClient(schema, "WHERE TRUE", trueChacker, 3));
         CheckSuccess(MakeClient(schema, "", trueChacker, 2));
 
@@ -323,7 +323,7 @@ Y_UNIT_TEST_SUITE(TestFormatHandler) {
     Y_UNIT_TEST_F(ClientValidation, TFormatHadlerFixture) {
         const TVector<TSchemaColumn> schema = {{"data", "[DataType; String]"}};
         const TString filter = "WHERE FALSE";
-        const auto callback = [&](TQueue<std::pair<TRope, TVector<ui64>>>&&) {};
+        const auto callback = EmptyCheck();
         CheckSuccess(MakeClient(schema, filter, callback, 0));
 
         CheckError(
@@ -349,27 +349,12 @@ Y_UNIT_TEST_SUITE(TestFormatHandler) {
         const ui64 firstOffset = 42;
         const TSchemaColumn commonColumn = {"com_col", "[DataType; String]"};
 
-        CheckSuccess(MakeClient(
-            {commonColumn, {"col_first", "[OptionalType; [DataType; Uint8]]"}},
-            "WHERE TRUE",
-            [&](TQueue<std::pair<TRope, TVector<ui64>>>&& data) {},
-            0
-        ));
+        CheckSuccess(MakeClient({commonColumn, {"col_first", "[OptionalType; [DataType; Uint8]]"}}, "WHERE TRUE", EmptyCheck(), 0));
 
         CheckSuccess(MakeClient(
             {commonColumn, {"col_second", "[DataType; String]"}},
             "WHERE col_second = \"str_second\"",
-            [&](TQueue<std::pair<TRope, TVector<ui64>>>&& data) {
-                UNIT_ASSERT_VALUES_EQUAL(data.size(), 1);
-
-                auto [messages, offsets] = data.front();
-                UNIT_ASSERT_VALUES_EQUAL(offsets.size(), 1);
-                UNIT_ASSERT_VALUES_EQUAL(offsets.front(), firstOffset);
-
-                CheckMessageBatch(messages, TBatch().AddRow(
-                    TRow().AddString("event1").AddString("str_second")
-                ));
-            }
+            OneRowCheck(firstOffset, TRow().AddString("event1").AddString("str_second"))
         ));
 
         CheckClientError(
@@ -379,6 +364,26 @@ Y_UNIT_TEST_SUITE(TestFormatHandler) {
             TStringBuilder() << "Failed to parse json string at offset " << firstOffset << ", got parsing error for column 'col_first' with type [OptionalType; [DataType; Uint8]]"
         );
     }
+
+    Y_UNIT_TEST_F(ClientErrorWithEmptyFilter, TFormatHadlerFixture) {
+        const ui64 firstOffset = 42;
+        const TSchemaColumn commonColumn = {"com_col", "[DataType; String]"};
+
+        CheckSuccess(MakeClient({commonColumn, {"col_first", "[DataType; String]"}}, "", EmptyCheck(), 0));
+
+        CheckSuccess(MakeClient(
+            {commonColumn, {"col_second", "[DataType; String]"}},
+            "WHERE col_second = \"str_second\"",
+            OneRowCheck(firstOffset, TRow().AddString("event1").AddString("str_second"))
+        ));
+
+        CheckClientError(
+            {GetMessage(firstOffset, R"({"com_col": "event1", "col_second": "str_second"})")},
+            ClientIds[0],
+            EStatusId::PRECONDITION_FAILED,
+            TStringBuilder() << "Failed to parse json messages, found 1 missing values from offset " << firstOffset << " in non optional column 'col_first' with type [DataType; String]"
+        );
+    }
 }
 
 }  // namespace NFq::NRowDispatcher::NTests
diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/topic_filter_ut.cpp b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/topic_filter_ut.cpp
index 7f0297219f..469e4f87c5 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/topic_filter_ut.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/topic_filter_ut.cpp
@@ -64,6 +64,13 @@ public:
             }
         }
 
+        void OnFilteredBatch(ui64 firstRow, ui64 lastRow) override {
+            UNIT_ASSERT_C(Started, "Unexpected data for not started filter");
+            for (ui64 rowId = firstRow; rowId <= lastRow; ++rowId) {
+                Callback(rowId);
+            }
+        }
+
         void OnFilteredData(ui64 rowId) override {
             UNIT_ASSERT_C(Started, "Unexpected data for not started filter");
             Callback(rowId);
diff --git a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/topic_parser_ut.cpp b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/topic_parser_ut.cpp
index 0f2d59d810..0895466e72 100644
--- a/ydb/core/fq/libs/row_dispatcher/format_handler/ut/topic_parser_ut.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/format_handler/ut/topic_parser_ut.cpp
@@ -414,9 +414,9 @@ Y_UNIT_TEST_SUITE(TestJsonParser) {
     Y_UNIT_TEST_F(JsonStructureValidation, TJsonParserFixture) {
         CheckSuccess(MakeParser({{"a1", "[OptionalType; [DataType; String]]"}}));
         CheckColumnError(R"({"a1": Yelse})", 0, EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse json string at offset " << FIRST_OFFSET << ", got parsing error for column 'a1' with type [OptionalType; [DataType; String]] subissue: { <main>: Error: Failed to determine json value type, current token: 'Yelse', error: TAPE_ERROR: The JSON document has an improper structure: missing or superfluous commas, braces, missing keys, etc. }");
-        CheckBatchError(R"({"a1": "st""r"})", EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse json message for offset " << FIRST_OFFSET + 1 << ", json item was corrupted: TAPE_ERROR: The JSON document has an improper structure: missing or superfluous commas, braces, missing keys, etc.");
-        CheckBatchError(R"({"a1": "x"} {"a1": "y"})", EStatusId::INTERNAL_ERROR, TStringBuilder() << "Failed to parse json messages, expected 1 json rows from offset " << FIRST_OFFSET + 2 << " but got 2");
-        CheckBatchError(R"({)", EStatusId::INTERNAL_ERROR, TStringBuilder() << "Failed to parse json messages, expected 1 json rows from offset " << FIRST_OFFSET + 3 << " but got 0");
+        CheckBatchError(R"({"a1": "st""r"})", EStatusId::BAD_REQUEST, TStringBuilder() << "Failed to parse json message for offset " << FIRST_OFFSET + 1 << ", json item was corrupted: TAPE_ERROR: The JSON document has an improper structure: missing or superfluous commas, braces, missing keys, etc. Current data batch: {\"a1\": \"st\"\"r\"}");
+        CheckBatchError(R"({"a1": "x"} {"a1": "y"})", EStatusId::INTERNAL_ERROR, TStringBuilder() << "Failed to parse json messages, expected 1 json rows from offset " << FIRST_OFFSET + 2 << " but got 2 (expected one json row for each offset from topic API in json each row format, maybe initial data was corrupted or messages is not in json format), current data batch: {\"a1\": \"x\"} {\"a1\": \"y\"}");
+        CheckBatchError(R"({)", EStatusId::INTERNAL_ERROR, TStringBuilder() << "Failed to parse json messages, expected 1 json rows from offset " << FIRST_OFFSET + 3 << " but got 0 (expected one json row for each offset from topic API in json each row format, maybe initial data was corrupted or messages is not in json format), current data batch: {");
     }
 }
 
diff --git a/ydb/core/fq/libs/row_dispatcher/topic_session.cpp b/ydb/core/fq/libs/row_dispatcher/topic_session.cpp
index c00e8d64fe..c79ee722f3 100644
--- a/ydb/core/fq/libs/row_dispatcher/topic_session.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/topic_session.cpp
@@ -709,7 +709,7 @@ void TTopicSession::StartClientSession(TClientsInfo& info) {
 
 void TTopicSession::Handle(NFq::TEvRowDispatcher::TEvStartSession::TPtr& ev) {
     const auto& source = ev->Get()->Record.GetSource();
-    LOG_ROW_DISPATCHER_INFO("New client: read actor id " << ev->Sender.ToString() << ", predicate: " << source.GetPredicate() << ", offset: " << ev->Get()->Record.GetOffset());
+    LOG_ROW_DISPATCHER_INFO("New client: read actor id " << ev->Sender.ToString() << ", predicate: '" << source.GetPredicate() << "', offset: " << ev->Get()->Record.GetOffset());
 
     if (!CheckNewClient(ev)) {
         return;
diff --git a/ydb/core/fq/libs/row_dispatcher/ut/topic_session_ut.cpp b/ydb/core/fq/libs/row_dispatcher/ut/topic_session_ut.cpp
index 82eb073241..3ca0528412 100644
--- a/ydb/core/fq/libs/row_dispatcher/ut/topic_session_ut.cpp
+++ b/ydb/core/fq/libs/row_dispatcher/ut/topic_session_ut.cpp
@@ -23,8 +23,9 @@ namespace {
 using namespace NKikimr;
 using namespace NYql::NDq;
 
-const ui64 TimeoutBeforeStartSessionSec = 3;
-const ui64 GrabTimeoutSec = 4 * TimeoutBeforeStartSessionSec;
+constexpr ui64 TimeoutBeforeStartSessionSec = 3;
+constexpr ui64 GrabTimeoutSec = 4 * TimeoutBeforeStartSessionSec;
+static_assert(GrabTimeoutSec <= WAIT_TIMEOUT.Seconds());
 
 class TFixture : public NTests::TBaseFixture {
 public: