Stabilize DR tests (#10750)

Author: FloatingCrowbar

ydb/core/persqueue/ut/common/pq_ut_common.cpp

@@ -722,11 +722,14 @@ void CmdSetOffset(const ui32 partition, const TString& user, ui64 offset, bool e
 
 
 TActorId CmdCreateSession(const TPQCmdSettings& settings, TTestContext& tc) {
-
     TActorId pipeClient = tc.Runtime->ConnectToPipe(tc.BalancerTabletId, tc.Edge, 0, GetPipeConfigWithRetries());
     TActorId tabletPipe = tc.Runtime->ConnectToPipe(tc.TabletId, tc.Edge, 0, GetPipeConfigWithRetries());
-
     TAutoPtr<IEventHandle> handle;
+    {
+        auto predicate = [&](const auto& ev) { return ev.TabletId == tc.TabletId; };
+        auto ev = tc.Runtime->GrabEdgeEventIf<TEvTabletPipe::TEvClientConnected>(handle, predicate);
+        UNIT_ASSERT(ev);
+    }
     TEvPersQueue::TEvResponse *result;
     THolder<TEvPersQueue::TEvRequest> request;
     for (i32 retriesLeft = 2; retriesLeft > 0; --retriesLeft) {

ydb/services/persqueue_v1/persqueue_ut.cpp

@@ -1167,7 +1167,7 @@ TPersQueueV1TestServer server{{.CheckACL=true, .NodeCount=1}};
     }
 
     Y_UNIT_TEST(DirectReadCleanCache) {
-        TPersQueueV1TestServer server;
+        TPersQueueV1TestServer server{{.NodeCount=1}};
         SET_LOCALS;
         TString topicPath{"/Root/PQ/rt3.dc1--acc--topic2"};
         server.Server->AnnoyingClient->CreateTopicNoLegacy(topicPath, 1);