Create a new session on closing of another can create deadlock

[alex268]

"grpc-default-worker-ELG-1-1" #57 daemon prio=5 os_prio=0 cpu=25024.63ms elapsed=2828.70s tid=0x00007fc0e6a9d010 nid=0x533f waiting on condition  [0x00007fc0e69f8000]
   java.lang.Thread.State: TIMED_WAITING (parking)
	at jdk.internal.misc.Unsafe.park(java.base@17.0.3-vanilla/Native Method)
	- parking to wait for  <0x00000000c36ea3d0> (a java.util.concurrent.CompletableFuture$Signaller)
	at java.util.concurrent.locks.LockSupport.parkNanos(java.base@17.0.3-vanilla/LockSupport.java:252)
	at java.util.concurrent.CompletableFuture$Signaller.block(java.base@17.0.3-vanilla/CompletableFuture.java:1866)
	at java.util.concurrent.ForkJoinPool.unmanagedBlock(java.base@17.0.3-vanilla/ForkJoinPool.java:3463)
	at java.util.concurrent.ForkJoinPool.managedBlock(java.base@17.0.3-vanilla/ForkJoinPool.java:3434)
	at java.util.concurrent.CompletableFuture.timedGet(java.base@17.0.3-vanilla/CompletableFuture.java:1939)
	at java.util.concurrent.CompletableFuture.get(java.base@17.0.3-vanilla/CompletableFuture.java:2095)
	at tech.ydb.core.impl.pool.GrpcChannel$ReadyWatcher.getReadyChannel(GrpcChannel.java:80)
	at tech.ydb.core.impl.pool.GrpcChannel.getReadyChannel(GrpcChannel.java:46)
	at tech.ydb.core.impl.BaseGrpcTransport.unaryCall(BaseGrpcTransport.java:84)
	at tech.ydb.table.rpc.grpc.GrpcTableRpc.createSession(GrpcTableRpc.java:50)
	at tech.ydb.table.impl.BaseSession.createSessionId(BaseSession.java:174)
	at tech.ydb.table.impl.pool.SessionPool$Handler.create(SessionPool.java:183)
	at tech.ydb.table.impl.pool.WaitingQueue.tryToCreateNewPending(WaitingQueue.java:226)
	at tech.ydb.table.impl.pool.WaitingQueue.checkNextWaitingAcquire(WaitingQueue.java:276)
	at tech.ydb.table.impl.pool.WaitingQueue.lambda$checkNextWaitingAcquire$0(WaitingQueue.java:279)
	at tech.ydb.table.impl.pool.WaitingQueue$$Lambda$2581/0x00000008013e9000.accept(Unknown Source)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(java.base@17.0.3-vanilla/CompletableFuture.java:863)
	at java.util.concurrent.CompletableFuture.uniWhenCompleteStage(java.base@17.0.3-vanilla/CompletableFuture.java:887)
	at java.util.concurrent.CompletableFuture.whenComplete(java.base@17.0.3-vanilla/CompletableFuture.java:2325)
	at tech.ydb.table.impl.pool.WaitingQueue.checkNextWaitingAcquire(WaitingQueue.java:277)
	at tech.ydb.table.impl.pool.WaitingQueue.lambda$checkNextWaitingAcquire$0(WaitingQueue.java:279)
	at tech.ydb.table.impl.pool.WaitingQueue$$Lambda$2581/0x00000008013e9000.accept(Unknown Source)

[maxim618]

This deadlock issue appears to be resolved in recent commits
Could you confirm that the fix is already included in the latest release (e.g., v2.3.21 and above)?
If so — I think this issue can be closed. Thanks!

[alex268]

This deadlock issue appears to be resolved in recent commits Could you confirm that the fix is already included in the latest release (e.g., v2.3.21 and above)? If so — I think this issue can be closed. Thanks!

Maybe your application problems were resolved in this PR 543, which was published in v2.3.22. But it is not resolved the root of this issue, deadlock is still be possible, and it must be resolved in PR 518. This PR is planned to be published in v2.4.0