Will the problem be solved if I increase the thread pool max value which is currently 400

Hello Ishita Virmani,

Greetings!

>>Will the problem be solved if I increase the thread pool max value which is currently 400

Increasing the thread pool value cannot solve the problem you are facing now. 

On reveiwing your report I could see almost 40% (i.e) 396 threads are in blocked state. When threads are blocked for prolonged period, your application will become unresponsive. 

'qtp1906565212-13756' thread is stuck on socketConnect() method in java.net.PlainSocketImpl file. Before getting stuck, this thread obtained 2 locks due to which

396 threads are BLOCKED as shown in the below screenshot.

Please find the stacktrace of the blocking thread 'qtp1906565212-13756' below from which you can identify the lines of code that is causing the performance problems in your application.

qtp1906565212-13756 Stack Trace is:
java.lang.Thread.State: RUNNABLE
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
- locked <0x000000071978b570> (a java.net.SocksSocketImpl)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at org.apache.thrift.transport.TSocket.open(TSocket.java:221)
at org.apache.zeppelin.interpreter.remote.RemoteInterpreterProcess.lambda$new$0(RemoteInterpreterProcess.java:58)
at org.apache.zeppelin.interpreter.remote.RemoteInterpreterProcess$$Lambda$339/1765457639.getWithIO(Unknown Source)
at org.apache.zeppelin.interpreter.remote.RemoteClientFactory.create(RemoteClientFactory.java:52)
at org.apache.zeppelin.interpreter.remote.RemoteClientFactory.create(RemoteClientFactory.java:31)
at org.apache.commons.pool2.BasePooledObjectFactory.makeObject(BasePooledObjectFactory.java:60)
at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:861)
at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:435)
at org.apache.zeppelin.interpreter.remote.PooledRemoteClient.getClient(PooledRemoteClient.java:55)
- locked <0x00000004b391b5a8> (a org.apache.zeppelin.interpreter.remote.PooledRemoteClient)
at org.apache.zeppelin.interpreter.remote.PooledRemoteClient.callRemoteFunction(PooledRemoteClient.java:99)
at org.apache.zeppelin.interpreter.remote.RemoteInterpreterProcess.callRemoteFunction(RemoteInterpreterProcess.java:100)
at org.apache.zeppelin.interpreter.InterpreterSettingManager.getAllResourcesExcept(InterpreterSettingManager.java:702)
at org.apache.zeppelin.interpreter.InterpreterSettingManager.getAllResources(InterpreterSettingManager.java:684)
at org.apache.zeppelin.helium.Helium.suggestApp(Helium.java:397)
at org.apache.zeppelin.rest.HeliumRestApi.suggest(HeliumRestApi.java:141)
at sun.reflect.GeneratedMethodAccessor22.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:52)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$$Lambda$229/1434527698.invoke(Unknown Source)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:124)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:167)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:176)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:79)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:469)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:391)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:80)
at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:253)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:248)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:244)
at org.glassfish.jersey.internal.Errors.process(Errors.java:292)
at org.glassfish.jersey.internal.Errors.process(Errors.java:274)
at org.glassfish.jersey.internal.Errors.process(Errors.java:244)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:265)
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:232)
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:680)
at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:394)
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:346)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:366)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:319)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:205)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:763)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1651)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:450)
at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:387)
at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1638)
at org.apache.zeppelin.server.CorsFilter.doFilter(CorsFilter.java:64)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1638)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:567)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:602)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1610)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1377)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:507)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1580)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1292)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:234)
at io.micrometer.core.instrument.binder.jetty.TimedHandler.handle(TimedHandler.java:120)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
at org.eclipse.jetty.server.Server.handle(Server.java:501)
at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:383)
at org.eclipse.jetty.server.HttpChannel$$Lambda$287/539823937.dispatch(Unknown Source)
at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:556)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:375)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:273)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
at org.eclipse.jetty.io.ssl.SslConnection$DecryptedEndPoint.onFillable(SslConnection.java:540)
at org.eclipse.jetty.io.ssl.SslConnection.onFillable(SslConnection.java:395)
at org.eclipse.jetty.io.ssl.SslConnection$2.succeeded(SslConnection.java:161)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:336)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:313)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:171)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:129)
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:375)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:806)
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:938)
at java.lang.Thread.run(Thread.java:748)

Thanks.

Hello Ishita!

 You are looking at the right direction only: line #55 of org.apache.zeppelin.interpreter.remote.PooledRemoteClient file in getClient() method is blocking 396 threads. This is a synchronized method. Looks like the thread which is enters this method is making a call to external system. There it's taking quite some time to return. 

Since it's a synchronized method, only one thread will be allowed to enter this method. Thus any other thread that is trying to enter this method is getting stuck. You need to investigate the call to the external system is taking such a long time. You need to check whether you have instrumented time outs for this external system call.