Better handling of connection loss

Author: CyberROFL

ydb/core/change_exchange/change_sender.cpp

@@ -61,20 +61,27 @@ void TChangeSender::RecreateSenders(const TVector<ui64>& partitionIds) {
     }
 }
 
-void TChangeSender::CreateSenders(const TVector<ui64>& partitionIds, bool partitioningChanged) {
-    if (partitioningChanged) {
+void TChangeSender::CreateSendersImpl(const TVector<ui64>& partitionIds) {
+    if (partitionIds) {
         CreateMissingSenders(partitionIds);
     } else {
-        RecreateSenders(GonePartitions);
+        RecreateSenders(std::exchange(GonePartitions, {}));
     }
 
-    GonePartitions.clear();
-
     if (!Enqueued || !RequestRecords()) {
         SendRecords();
     }
 }
 
+void TChangeSender::CreateSenders(const TVector<ui64>& partitionIds) {
+    Y_ABORT_UNLESS(partitionIds);
+    CreateSendersImpl(partitionIds);
+}
+
+void TChangeSender::CreateSenders() {
+    CreateSendersImpl({});
+}
+
 void TChangeSender::KillSenders() {
     for (const auto& [_, sender] : std::exchange(Senders, {})) {
         if (sender.ActorId) {
@@ -303,6 +310,7 @@ void TChangeSender::OnGone(ui64 partitionId) {
     if (it->second.Ready) {
         --ReadySenders;
     }
+
     Senders.erase(it);
     GonePartitions.push_back(partitionId);
 

ydb/core/change_exchange/change_sender.h

@@ -113,6 +113,7 @@ class TChangeSender {
         THashSet<ui64> CompletedPartitions;
     };
 
+    void CreateSendersImpl(const TVector<ui64>& partitionIds);
     void LazyCreateSender(THashMap<ui64, TSender>& senders, ui64 partitionId);
     void RegisterSender(ui64 partitionId);
     void CreateMissingSenders(const TVector<ui64>& partitionIds);
@@ -150,7 +151,8 @@ class TChangeSender {
         return ChangeServer;
     }
 
-    void CreateSenders(const TVector<ui64>& partitionIds, bool partitioningChanged = true);
+    void CreateSenders(const TVector<ui64>& partitionIds); // creates senders after partitioning changes
+    void CreateSenders(); // creates senders after connection loss
     void KillSenders();
 
     void EnqueueRecords(TVector<TEvChangeExchange::TEvEnqueueRecords::TRecordInfo>&& records);

ydb/core/change_exchange/util.cpp

@@ -0,0 +1,15 @@
+#include "util.h"
+
+namespace NKikimr::NChangeExchange {
+
+TVector<ui64> MakePartitionIds(const TVector<TKeyDesc::TPartitionInfo>& partitions) {
+    TVector<ui64> result(::Reserve(partitions.size()));
+
+    for (const auto& partition : partitions) {
+        result.push_back(partition.ShardId);
+    }
+
+    return result;
+}
+
+}

ydb/core/change_exchange/util.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include <ydb/core/scheme/scheme_tabledefs.h>
+
+namespace NKikimr::NChangeExchange {
+
+TVector<ui64> MakePartitionIds(const TVector<TKeyDesc::TPartitionInfo>& partitions);
+
+}

ydb/core/change_exchange/ya.make

@@ -6,6 +6,7 @@ SRCS(
     change_sender.cpp
     change_sender_monitoring.cpp
     resolve_partition.cpp
+    util.cpp
 )
 
 GENERATE_ENUM_SERIALIZATION(change_record.h)

ydb/core/tx/datashard/change_sender_cdc_stream.cpp

@@ -6,6 +6,7 @@
 
 #include <ydb/core/change_exchange/change_sender.h>
 #include <ydb/core/change_exchange/change_sender_monitoring.h>
+#include <ydb/core/change_exchange/util.h>
 #include <ydb/core/persqueue/writer/source_id_encoding.h>
 #include <ydb/core/persqueue/writer/writer.h>
 #include <ydb/core/tx/scheme_cache/helpers.h>
@@ -440,16 +441,6 @@ class TCdcChangeSenderMain
         return false;
     }
 
-    static TVector<ui64> MakePartitionIds(const TVector<NKikimr::TKeyDesc::TPartitionInfo>& partitions) {
-        TVector<ui64> result(Reserve(partitions.size()));
-
-        for (const auto& partition : partitions) {
-            result.push_back(partition.ShardId);
-        }
-
-        return result;
-    }
-
     /// ResolveCdcStream
 
     void ResolveCdcStream() {
@@ -571,6 +562,14 @@ class TCdcChangeSenderMain
             return;
         }
 
+        const auto topicVersion = entry.Self->Info.GetVersion().GetGeneralVersion();
+        if (TopicVersion && TopicVersion == topicVersion) {
+            CreateSenders();
+            return Become(&TThis::StateMain);
+        }
+
+        TopicVersion = topicVersion;
+
         const auto& pqDesc = entry.PQGroupInfo->Description;
         const auto& pqConfig = pqDesc.GetPQTabletConfig();
 
@@ -579,12 +578,7 @@ class TCdcChangeSenderMain
             PartitionToShard.emplace(partition.GetPartitionId(), partition.GetTabletId());
         }
 
-        const auto topicVersion = entry.Self->Info.GetVersion().GetGeneralVersion();
-        const bool versionChanged = !TopicVersion || TopicVersion != topicVersion;
-        TopicVersion = topicVersion;
-
-        auto topicAutoPartitioning = ::NKikimrPQ::TPQTabletConfig::TPartitionStrategyType::TPQTabletConfig_TPartitionStrategyType_DISABLED != pqConfig.GetPartitionStrategy().GetPartitionStrategyType();
-
+        const bool topicAutoPartitioning = IsTopicAutoPartitioningEnabled(pqConfig.GetPartitionStrategy().GetPartitionStrategyType());
         Y_ABORT_UNLESS(topicAutoPartitioning || entry.PQGroupInfo->Schema);
         KeyDesc = NKikimr::TKeyDesc::CreateMiniKeyDesc(entry.PQGroupInfo->Schema);
         Y_ABORT_UNLESS(entry.PQGroupInfo->Partitioning);
@@ -598,10 +592,14 @@ class TCdcChangeSenderMain
             SetPartitionResolver(new TMd5PartitionResolver(KeyDesc->GetPartitions().size()));
         }
 
-        CreateSenders(MakePartitionIds(*KeyDesc->Partitioning), versionChanged);
+        CreateSenders(NChangeExchange::MakePartitionIds(*KeyDesc->Partitioning));
         Become(&TThis::StateMain);
     }
 
+    static bool IsTopicAutoPartitioningEnabled(NKikimrPQ::TPQTabletConfig::TPartitionStrategyType strategy) {
+        return strategy != NKikimrPQ::TPQTabletConfig::TPartitionStrategyType::TPQTabletConfig_TPartitionStrategyType_DISABLED;
+    }
+
     /// Main
 
     STATEFN(StateMain) {

ydb/core/tx/datashard/change_sender_table_base.h

@@ -2,6 +2,7 @@
 
 #include "change_exchange_helpers.h"
 
+#include <ydb/core/change_exchange/util.h>
 #include <ydb/core/tablet_flat/flat_row_state.h>
 #include <ydb/core/tx/scheme_cache/helpers.h>
 
@@ -151,6 +152,11 @@ class TResolveTargetTableState
             return;
         }
 
+        if (AsDerived()->TargetTableVersion && AsDerived()->TargetTableVersion == entry.Self->Info.GetVersion().GetGeneralVersion()) {
+            AsDerived()->CreateSenders();
+            return AsDerived()->Serve();
+        }
+
         AsDerived()->TagMap.clear();
         TVector<NScheme::TTypeInfo> keyColumnTypes;
 
@@ -181,7 +187,6 @@ class TResolveTargetTableState
         );
 
         AsDerived()->SetPartitionResolver(CreateDefaultPartitionResolver(*AsDerived()->KeyDesc.Get()));
-
         AsDerived()->NextState(TStateTag{});
     }
 };
@@ -245,24 +250,12 @@ class TResolveKeysState
             return AsDerived()->Retry();
         }
 
-        const bool versionChanged = !AsDerived()->TargetTableVersion || AsDerived()->TargetTableVersion != entry.GeneralVersion;
         AsDerived()->TargetTableVersion = entry.GeneralVersion;
-
         AsDerived()->KeyDesc = std::move(entry.KeyDescription);
-        AsDerived()->CreateSenders(MakePartitionIds(AsDerived()->KeyDesc->GetPartitions()), versionChanged);
+        AsDerived()->CreateSenders(NChangeExchange::MakePartitionIds(AsDerived()->KeyDesc->GetPartitions()));
 
         AsDerived()->NextState(TStateTag{});
     }
-
-    static TVector<ui64> MakePartitionIds(const TVector<TKeyDesc::TPartitionInfo>& partitions) {
-        TVector<ui64> result(Reserve(partitions.size()));
-
-        for (const auto& partition : partitions) {
-            result.push_back(partition.ShardId); // partition = shard
-        }
-
-        return result;
-    }
 };
 
 template <typename TDerived>

ydb/core/tx/replication/service/base_table_writer.cpp

@@ -4,6 +4,7 @@
 
 #include <ydb/core/base/tablet_pipecache.h>
 #include <ydb/core/change_exchange/change_sender.h>
+#include <ydb/core/change_exchange/util.h>
 #include <ydb/core/tablet_flat/flat_row_eggs.h>
 #include <ydb/core/tx/datashard/datashard.h>
 #include <ydb/core/tx/scheme_cache/helpers.h>
@@ -268,16 +269,6 @@ class TLocalTableWriter
         return Check(&TSchemeCacheHelpers::CheckEntryKind<T>, &TThis::LogCritAndLeave, entry, expected);
     }
 
-    static TVector<ui64> MakePartitionIds(const TVector<TKeyDesc::TPartitionInfo>& partitions) {
-        TVector<ui64> result(::Reserve(partitions.size()));
-
-        for (const auto& partition : partitions) {
-            result.push_back(partition.ShardId);
-        }
-
-        return result;
-    }
-
     void Registered(TActorSystem*, const TActorId&) override {
         ChangeServer = SelfId();
     }
@@ -338,6 +329,12 @@ class TLocalTableWriter
             return;
         }
 
+        if (TableVersion && TableVersion == entry.Self->Info.GetVersion().GetGeneralVersion()) {
+            Y_ABORT_UNLESS(Initialized);
+            Resolving = false;
+            return CreateSenders();
+        }
+
         auto schema = MakeIntrusive<TLightweightSchema>();
         if (entry.Self && entry.Self->Info.HasVersion()) {
             schema->Version = entry.Self->Info.GetVersion().GetTableSchemaVersion();
@@ -370,7 +367,6 @@ class TLocalTableWriter
         );
 
         TChangeSender::SetPartitionResolver(CreateResolverFn(*KeyDesc.Get()));
-
         ResolveKeys();
     }
 
@@ -408,11 +404,9 @@ class TLocalTableWriter
             return LogWarnAndRetry("Empty partitions");
         }
 
-        const bool versionChanged = !TableVersion || TableVersion != entry.GeneralVersion;
         TableVersion = entry.GeneralVersion;
-
         KeyDesc = std::move(entry.KeyDescription);
-        CreateSenders(MakePartitionIds(KeyDesc->GetPartitions()), versionChanged);
+        CreateSenders(NChangeExchange::MakePartitionIds(KeyDesc->GetPartitions()));
 
         if (!Initialized) {
             Send(Worker, new TEvWorker::TEvHandshake());