Fix volatile transactions getting stuck after a restart

Author: snaury

ydb/core/tx/datashard/datashard_ut_volatile.cpp

@@ -5,6 +5,7 @@
 
 #include <ydb/core/base/blobstorage.h>
 #include <ydb/core/kqp/executer_actor/kqp_executer.h>
+#include <ydb/core/testlib/actors/block_events.h>
 
 namespace NKikimr {
 
@@ -2989,6 +2990,94 @@ Y_UNIT_TEST_SUITE(DataShardVolatile) {
             "ERROR: ABORTED");
     }
 
+    Y_UNIT_TEST(UpsertDependenciesShardsRestart) {
+        TPortManager pm;
+        TServerSettings serverSettings(pm.GetPort(2134));
+        serverSettings.SetDomainName("Root")
+            .SetUseRealThreads(false)
+            .SetEnableDataShardVolatileTransactions(true);
+
+        Tests::TServer::TPtr server = new TServer(serverSettings);
+        auto &runtime = *server->GetRuntime();
+        auto sender = runtime.AllocateEdgeActor();
+
+        runtime.SetLogPriority(NKikimrServices::TX_DATASHARD, NLog::PRI_TRACE);
+        runtime.SetLogPriority(NKikimrServices::PIPE_CLIENT, NLog::PRI_TRACE);
+
+        InitRoot(server, sender);
+
+        UNIT_ASSERT_VALUES_EQUAL(
+            KqpSchemeExec(runtime, R"(
+                CREATE TABLE `/Root/table` (key uint32, value uint32, PRIMARY KEY (key))
+                WITH (PARTITION_AT_KEYS = (10));
+            )"),
+            "SUCCESS");
+
+        const auto shards = GetTableShards(server, sender, "/Root/table");
+        UNIT_ASSERT_VALUES_EQUAL(shards.size(), 2u);
+
+        // We need to fill table with some data
+        Cerr << "========= Upserting initial values =========" << Endl;
+        KqpSimpleExec(runtime, R"(
+            UPSERT INTO `/Root/table` (key, subkey, value)
+            VALUES (1, 1), (11, 11)
+            )");
+
+        TForceVolatileProposeArbiter forceArbiter(runtime, shards.at(0));
+        TBlockEvents<TEvTxProcessing::TEvPlanStep> blockedPlan(runtime,
+            [actor = ResolveTablet(runtime, shards.at(0))](const auto& ev) {
+                return ev->GetRecipientRewrite() == actor;
+            });
+
+        Cerr << "========= Starting upsert 1 =========" << Endl;
+        auto upsertFuture1 = KqpSimpleSend(runtime, R"(
+            UPSERT INTO `/Root/table` (key, value)
+            VALUES (2, 2), (12, 12);
+            )");
+        runtime.SimulateSleep(TDuration::Seconds(1));
+
+        Cerr << "========= Starting upsert 2 =========" << Endl;
+        auto upsertFuture2 = KqpSimpleSend(runtime, R"(
+            UPSERT INTO `/Root/table` (key, value)
+            VALUES (2, 1002), (12, 1012);
+            )");
+        runtime.SimulateSleep(TDuration::Seconds(1));
+
+        UNIT_ASSERT_VALUES_EQUAL(blockedPlan.size(), 2u);
+
+        // We expect transaction to execute at shards[1]
+        // However at shards[0] it didn't even start due to blocked plans
+        // Now we need to restart both shards, without giving them a change to communicate
+        std::vector<TActorId> shardActors{
+            ResolveTablet(runtime, shards.at(0)),
+            ResolveTablet(runtime, shards.at(1)),
+        };
+        for (auto& shardActor : shardActors) {
+            Cerr << "... killing actor " << shardActor << Endl;
+            // Perform a synchronous send, this makes sure both shards handle TEvPoison
+            runtime.Send(new IEventHandle(shardActor, TActorId(), new TEvents::TEvPoison), 0, /* viaActorSystem */ false);
+        }
+
+        blockedPlan.Stop().clear();
+
+        // Both queries should abort with UNDETERMINED
+        Cerr << "... waiting for query results" << Endl;
+        UNIT_ASSERT_VALUES_EQUAL(
+            FormatResult(runtime.WaitFuture(std::move(upsertFuture1))),
+            "ERROR: UNDETERMINED");
+        UNIT_ASSERT_VALUES_EQUAL(
+            FormatResult(runtime.WaitFuture(std::move(upsertFuture2))),
+            "ERROR: UNDETERMINED");
+
+        // Split the second shard, which makes sure it's not stuck
+        Cerr << "========= Splitting shard 2 =========" << Endl;
+        SetSplitMergePartCountLimit(server->GetRuntime(), -1);
+        ui64 txId = AsyncSplitTable(server, sender, "/Root/table", shards.at(1), 15);
+        Cerr << "... split txId# " << txId << " started" << Endl;
+        WaitTxNotification(server, sender, txId);
+        Cerr << "... split finished" << Endl;
+    }
+
 } // Y_UNIT_TEST_SUITE(DataShardVolatile)
 
 } // namespace NKikimr

ydb/core/tx/datashard/volatile_tx.cpp

@@ -271,9 +271,6 @@ namespace NKikimr::NDataShard {
 
     void TVolatileTxManager::Start(const TActorContext& ctx) {
         for (auto& pr : VolatileTxs) {
-            if (!pr.second->Dependencies.empty()) {
-                continue;
-            }
             switch (pr.second->State) {
                 case EVolatileTxState::Waiting:
                     for (ui64 target : pr.second->Participants) {