[SSHD-931] SftpSubsystem.destroy() will terminate external FixedThreadPool ExecutorService - preventing re-connects

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.2.0
• Fix Version/s: 2.4.0
• Environment: Linux RH
• Assignee: Lyor Goldstein
• Reporter: Alla Gofman
• Created: 14/Jul/19 17:34
• Updated: 08/Jun/20 13:33
• Resolved: 05/Aug/19 06:51

Description

Similar bug from the 1.2.0 version
https://issues.apache.org/jira/browse/SSHD-669

 

In SftpSubsystem on performing the destroy logic (on a client disconnect f.e.), the code will also terminate the current executor service as well.

https://github.com/apache/mina-sshd/blob/master/sshd-sftp/src/main/java/org/apache/sshd/server/subsystem/sftp/SftpSubsystem.java#L1001

 *** There is no shutdownExecutor parameter in SftpSubsystem.

 

2019-07-14 19:00:14,236 ERROR [sshd-FactoryExecutorService-thread-1] (SftpSubsystem:316) - run(ServerSessionImpl[user1@DOMAIN/137.72.216.21:50597]) InterruptedException caught in SFTP subsystem: null

2019-07-14 19:00:14,236 DEBUG [sshd-FactoryExecutorService-thread-1] (SftpSubsystem:319) - run(ServerSessionImpl[[e-mail]/137.72.216.21:50597]) caught exception details
java.lang.InterruptedException: null
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.reportInterruptAfterWait(AbstractQueuedSynchronizer.java:2056) ~[?:?]
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2090) ~[?:?]
at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:433) ~[?:?]
at org.apache.sshd.server.subsystem.sftp.SftpSubsystem.run(SftpSubsystem.java:304) [sshd-sftp-2.2.0.jar!/:2.2.0]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) [?:?]
at java.util.concurrent.FutureTask.run(FutureTask.java:264) [?:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
at java.lang.Thread.run(Thread.java:834) [?:?]

----------------------------------------------------------------------------------------------------------------------

Using protectExecutorServiceShutdown wrapper with shutdownOnExit = false will not solve the problem due to another exception thrown from NoCloseExecutor by
ValidateUtils.checkState(!isShutdown(), "Executor has been shut down");

***The second time Unable to render embedded object: File (isShutdown() issues it will return true) not found.!!

https://github.com/apache/mina-sshd/blob/master/sshd-common/src/main/java/org/apache/sshd/common/util/threads/NoCloseExecutor.java#L66

2019-07-12 22:18:07,097 ERROR [sshd-SshServer[3245efdb](port=1222)-nio2-thread-8] (HubSftpSubsystemWrapper:274) - Failed (IllegalStateException) to start command: java.lang.IllegalStateException: Executor has been shut down
java.lang.IllegalStateException: Executor has been shut down
at org.apache.sshd.common.util.ValidateUtils.createFormattedException(ValidateUtils.java:213) ~[sshd-common-2.2.0.jar!/:2.2.0]
at org.apache.sshd.common.util.ValidateUtils.throwIllegalStateException(ValidateUtils.java:207) ~[sshd-common-2.2.0.jar!/:2.2.0]
at org.apache.sshd.common.util.ValidateUtils.checkState(ValidateUtils.java:184) ~[sshd-common-2.2.0.jar!/:2.2.0]
at org.apache.sshd.common.util.threads.NoCloseExecutor.submit(NoCloseExecutor.java:66) ~[sshd-common-2.2.0.jar!/:2.2.0]

 

Issue Links

• relates to: SSHD-669 Destroying SftpSubsystem on client disconnect will terminate external ExecutorService - preventing re-connects