On 09/12/2014 17:01, Nikita Zyulyaev wrote: > Greetings! > > I’ve got a problem using Tomcat 7.0.47 NioConnector with nginx 1.6.2 and > atmosphere 2.2.3. > > It happens when nginx and atmosphere close the same comet connection > concurrently. > > In NioEndpoint.Poller thread(A) the SocketChannel becomes ready for read when > nginx closes it. Poller unregisters the channel for read and forks another > thread(B) to handle close event. (see NioEndpoint:1239) > Then atmosphere calls close on the connection in thread(C) and Tomcat > receives internal action with code ActionCode.COMET_CLOSE and adds the > channel to the Poller, which registers it for read again. (see > Http11NioProcessor.java:462). > The SocketChannel is still readable in case thread(B) hasn’t invalidated the > SelectionKey yet, so Poller in thread(A) initiates the closing process again > and forks thread(D). > Thread(B) completes the closing process and puts NioChannel and AttachmentKey > into the corresponding caches. > Then Thread(D) tries to close the channel again and realizes that it has > already been closed (see AbstractProtocol.java:564) and puts the same > NioChannel and AttachmentKey into caches. > Caches become corrupted because they contain 2 references to the same object. > Then any 2 subsequent requests may get the same NioChannel and AttachmentKey > and some crazy stuff may happen (mixed up responses, etc). > > Looks like it is a concurrency issue in Tomcat.
Agreed. Please open a Bugzilla issue for this. Mark > > P.S. > When testing without nginx it does not reproduce due to the fact that the > browser doesn’t close the connection and reuses it. > > Thanks. > Nikita Zyulyaev. > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
