From d0e18892195e188776634957aa1595062733e06d Mon Sep 17 00:00:00 2001
From: Evgeny Zverev <zverevgeny@ydb.tech>
Date: Tue, 7 Jan 2025 07:05:11 +0000
Subject: [PATCH 1/2] Do not clear shard lists

---
 .../tx/columnshard/columnshard__write.cpp     | 33 +++++++++----------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/ydb/core/tx/columnshard/columnshard__write.cpp b/ydb/core/tx/columnshard/columnshard__write.cpp
index b54f174c3a99..4e3e565952fb 100644
--- a/ydb/core/tx/columnshard/columnshard__write.cpp
+++ b/ydb/core/tx/columnshard/columnshard__write.cpp
@@ -317,29 +317,28 @@ class TCommitOperation {
     }
 
     TConclusionStatus Parse(const NEvents::TDataEvents::TEvWrite& evWrite) {
-        AFL_VERIFY(evWrite.Record.GetLocks().GetLocks().size() >= 1);
-        auto& locks = evWrite.Record.GetLocks();
-        auto& lock = evWrite.Record.GetLocks().GetLocks()[0];
+        TxId = evWrite.Record.GetTxId();
+        NActors::TLogContextGuard lGuard = NActors::TLogContextBuilder::Build()("tx_id", TxId);
+        const auto& locks = evWrite.Record.GetLocks();
+        AFL_VERIFY(!locks.GetLocks().empty());
+        auto& lock = locks.GetLocks()[0];
+        LockId = lock.GetLockId();
         SendingShards = std::set<ui64>(locks.GetSendingShards().begin(), locks.GetSendingShards().end());
         ReceivingShards = std::set<ui64>(locks.GetReceivingShards().begin(), locks.GetReceivingShards().end());
-        if (!ReceivingShards.size() || !SendingShards.size()) {
-            ReceivingShards.clear();
-            SendingShards.clear();
-        } else if (!locks.HasArbiterColumnShard()) {
-            ArbiterColumnShard = *ReceivingShards.begin();
+        const bool singleShardTx = SendingShards.empty() && ReceivingShards.empty();
+        if (!singleShardTx) {
             if (!ReceivingShards.contains(TabletId) && !SendingShards.contains(TabletId)) {
-                return TConclusionStatus::Fail("shard is incorrect for sending/receiving lists");
+                return TConclusionStatus::Fail("shard is absent in sending and receiving lists");
             }
-        } else {
-            ArbiterColumnShard = locks.GetArbiterColumnShard();
-            AFL_VERIFY(ArbiterColumnShard);
-            if (!ReceivingShards.contains(TabletId) && !SendingShards.contains(TabletId)) {
-                return TConclusionStatus::Fail("shard is incorrect for sending/receiving lists");
+            if (locks.HasArbiterColumnShard()) {
+                ArbiterColumnShard = locks.GetArbiterColumnShard();
+            } else {
+                AFL_VERIFY(!ReceivingShards.empty());
+                ArbiterColumnShard = *ReceivingShards.begin();
             }
+            AFL_VERIFY(ArbiterColumnShard);
         }
 
-        TxId = evWrite.Record.GetTxId();
-        LockId = lock.GetLockId();
         Generation = lock.GetGeneration();
         InternalGenerationCounter = lock.GetCounter();
         if (!GetLockId()) {
@@ -348,7 +347,7 @@ class TCommitOperation {
         if (!TxId) {
             return TConclusionStatus::Fail("not initialized TxId for commit event");
         }
-        if (evWrite.Record.GetLocks().GetOp() != NKikimrDataEvents::TKqpLocks::Commit) {
+        if (locks.GetOp() != NKikimrDataEvents::TKqpLocks::Commit) {
             return TConclusionStatus::Fail("incorrect message type");
         }
         return TConclusionStatus::Success();

From b27f421fd839c8d0337531ace89ed98c9c682784 Mon Sep 17 00:00:00 2001
From: Evgeny Zverev <zverevgeny@ydb.tech>
Date: Tue, 7 Jan 2025 07:58:32 +0000
Subject: [PATCH 2/2] fix empty receiving shards

---
 ydb/core/tx/columnshard/columnshard__write.cpp                | 3 +--
 .../tx/columnshard/transactions/operators/ev_write/primary.h  | 4 +---
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/ydb/core/tx/columnshard/columnshard__write.cpp b/ydb/core/tx/columnshard/columnshard__write.cpp
index 4e3e565952fb..bea7766dc3c8 100644
--- a/ydb/core/tx/columnshard/columnshard__write.cpp
+++ b/ydb/core/tx/columnshard/columnshard__write.cpp
@@ -304,7 +304,7 @@ class TCommitOperation {
     using TPtr = std::shared_ptr<TCommitOperation>;
 
     bool NeedSyncLocks() const {
-        return SendingShards.size() && ReceivingShards.size();
+        return SendingShards.size() || ReceivingShards.size();
     }
 
     bool IsPrimary() const {
@@ -355,7 +355,6 @@ class TCommitOperation {
 
     std::unique_ptr<NColumnShard::TEvWriteCommitSyncTransactionOperator> CreateTxOperator(
         const NKikimrTxColumnShard::ETransactionKind kind) const {
-        AFL_VERIFY(ReceivingShards.size());
         if (IsPrimary()) {
             return std::make_unique<NColumnShard::TEvWriteCommitPrimaryTransactionOperator>(
                 TFullTxInfo::BuildFake(kind), LockId, ReceivingShards, SendingShards);
diff --git a/ydb/core/tx/columnshard/transactions/operators/ev_write/primary.h b/ydb/core/tx/columnshard/transactions/operators/ev_write/primary.h
index 0a8137fd9d31..8fc19f3c8587 100644
--- a/ydb/core/tx/columnshard/transactions/operators/ev_write/primary.h
+++ b/ydb/core/tx/columnshard/transactions/operators/ev_write/primary.h
@@ -63,7 +63,6 @@ class TEvWriteCommitPrimaryTransactionOperator: public TEvWriteCommitSyncTransac
         for (auto&& i : protoData.GetWaitShardsResultAck()) {
             WaitShardsResultAck.emplace(i);
         }
-        AFL_VERIFY(ReceivingShards.empty() == SendingShards.empty());
         if (protoData.HasTxBroken()) {
             TxBroken = protoData.GetTxBroken();
         }
@@ -160,8 +159,7 @@ class TEvWriteCommitPrimaryTransactionOperator: public TEvWriteCommitSyncTransac
     };
 
     virtual bool IsTxBroken() const override {
-        AFL_VERIFY(TxBroken);
-        return *TxBroken;
+        return TxBroken.value_or(false);
     }
 
     void InitializeRequests(TColumnShard& owner) {