Re: I/O thread blocking under high concurrent load
Hi, Yes of course. The reason behind my concern is all these blocks seems to be occurred in EPoll related operations and there are quite a lot of these blocks. I'm worried about this has a impact on the performance of the application. Is there any configuration parameter to switch off this EPoll usage in order to perform a round of testing without it. Thanks Regards, Sudheera. On Thu, Feb 2, 2017 at 5:36 PM, Oleg Kalnichevski wrote: > On February 2, 2017 7:05:07 AM GMT+01:00, Sudheera Palihakkara < > catchsudhe...@gmail.com> wrote: > >Hi all, > > > >I'm currently using httpcore-nio 4.4 for a proxy-like application and > >make > >use of the file channels when content transferring. Recently I have > >profiled my code under a high concurrent load and observed few unusual > >thread blocking occurrences. Stack traces are listed below. > > > >*I/O threads* > > > >S-I/O-dispatcher-1 [BLOCKED] > >sun.nio.ch.EPollSelectorImpl.doSelect(long) EPollSelectorImpl.java:88 > >java.lang.Thread.run() Thread.java:745 > > > >S-I/O-dispatcher-5 [BLOCKED] > >org.apache.http.impl.nio.reactor.IOSessionImpl.setEvent(int) > >IOSessionImpl.java:164 > >org.apache.http.impl.nio.DefaultNHttpClientConnection. > submitRequest(HttpRequest) > >DefaultNHttpClientConnection.java:339 > > > >*Worker threds* > > > >pool-2-thread-99 [BLOCKED] > >sun.nio.ch.EPollArrayWrapper.setInterest(int, int) > >EPollArrayWrapper.java:213 > >org.apache.http.nio.protocol.HttpAsyncService$HttpAsyncExchangeImpl. > submitResponse(HttpAsyncResponseProducer) > >HttpAsyncService.java:1037 > > > >pool-2-thread-96 [BLOCKED] > >sun.nio.ch.EPollSelectorImpl.wakeup() EPollSelectorImpl.java:191 > >org.apache.http.nio.protocol.HttpAsyncService$HttpAsyncExchangeImpl. > submitResponse(HttpAsyncResponseProducer) > >HttpAsyncService.java:1037 > > > >Previously I have used httpcore-nio 4.2.5 for the same application and > >did > >not encountered any such thread blockings. Can you help me out to > >figure > >out what might be the issue here? Thank you very much. > > Synchronized sections of code can cause threads to block on the > synchronization object under load. This does not necessarily mean there is > a problem. > > Oleg > -- > Sent from my Android device with K-9 Mail. Please excuse my brevity. > -- *Sudheera Palihakkara.* Undergraduate Department of *Computer Science and Engineering,*Faculty of Engineering, *University of Moratuwa*, Sri Lanka.
Re: I/O thread blocking under high concurrent load
On February 2, 2017 7:05:07 AM GMT+01:00, Sudheera Palihakkara wrote: >Hi all, > >I'm currently using httpcore-nio 4.4 for a proxy-like application and >make >use of the file channels when content transferring. Recently I have >profiled my code under a high concurrent load and observed few unusual >thread blocking occurrences. Stack traces are listed below. > >*I/O threads* > >S-I/O-dispatcher-1 [BLOCKED] >sun.nio.ch.EPollSelectorImpl.doSelect(long) EPollSelectorImpl.java:88 >java.lang.Thread.run() Thread.java:745 > >S-I/O-dispatcher-5 [BLOCKED] >org.apache.http.impl.nio.reactor.IOSessionImpl.setEvent(int) >IOSessionImpl.java:164 >org.apache.http.impl.nio.DefaultNHttpClientConnection.submitRequest(HttpRequest) >DefaultNHttpClientConnection.java:339 > >*Worker threds* > >pool-2-thread-99 [BLOCKED] >sun.nio.ch.EPollArrayWrapper.setInterest(int, int) >EPollArrayWrapper.java:213 >org.apache.http.nio.protocol.HttpAsyncService$HttpAsyncExchangeImpl.submitResponse(HttpAsyncResponseProducer) >HttpAsyncService.java:1037 > >pool-2-thread-96 [BLOCKED] >sun.nio.ch.EPollSelectorImpl.wakeup() EPollSelectorImpl.java:191 >org.apache.http.nio.protocol.HttpAsyncService$HttpAsyncExchangeImpl.submitResponse(HttpAsyncResponseProducer) >HttpAsyncService.java:1037 > >Previously I have used httpcore-nio 4.2.5 for the same application and >did >not encountered any such thread blockings. Can you help me out to >figure >out what might be the issue here? Thank you very much. Synchronized sections of code can cause threads to block on the synchronization object under load. This does not necessarily mean there is a problem. Oleg -- Sent from my Android device with K-9 Mail. Please excuse my brevity. - To unsubscribe, e-mail: httpclient-users-unsubscr...@hc.apache.org For additional commands, e-mail: httpclient-users-h...@hc.apache.org
I/O thread blocking under high concurrent load
Hi all, I'm currently using httpcore-nio 4.4 for a proxy-like application and make use of the file channels when content transferring. Recently I have profiled my code under a high concurrent load and observed few unusual thread blocking occurrences. Stack traces are listed below. *I/O threads* S-I/O-dispatcher-1 [BLOCKED] sun.nio.ch.EPollSelectorImpl.doSelect(long) EPollSelectorImpl.java:88 java.lang.Thread.run() Thread.java:745 S-I/O-dispatcher-5 [BLOCKED] org.apache.http.impl.nio.reactor.IOSessionImpl.setEvent(int) IOSessionImpl.java:164 org.apache.http.impl.nio.DefaultNHttpClientConnection.submitRequest(HttpRequest) DefaultNHttpClientConnection.java:339 *Worker threds* pool-2-thread-99 [BLOCKED] sun.nio.ch.EPollArrayWrapper.setInterest(int, int) EPollArrayWrapper.java:213 org.apache.http.nio.protocol.HttpAsyncService$HttpAsyncExchangeImpl.submitResponse(HttpAsyncResponseProducer) HttpAsyncService.java:1037 pool-2-thread-96 [BLOCKED] sun.nio.ch.EPollSelectorImpl.wakeup() EPollSelectorImpl.java:191 org.apache.http.nio.protocol.HttpAsyncService$HttpAsyncExchangeImpl.submitResponse(HttpAsyncResponseProducer) HttpAsyncService.java:1037 Previously I have used httpcore-nio 4.2.5 for the same application and did not encountered any such thread blockings. Can you help me out to figure out what might be the issue here? Thank you very much. -- *Sudheera Palihakkara.* Undergraduate Department of *Computer Science and Engineering,*Faculty of Engineering, *University of Moratuwa*, Sri Lanka.
