On Thu, 2010-07-15 at 12:50 -0700, Harold Lee wrote: > I've put together a simple HTTP server that resets the connection > after sending part of the response back to the client. I'm going to > try to recreate the bug (leaking sockets) by making many requests > against that server from a Linux box. I'll let you know what I find. > > Harold >
> On Wed, Jul 14, 2010 at 1:44 AM, Oleg Kalnichevski <ol...@apache.org> wrote: > > On Tue, 2010-07-13 at 13:32 -0700, Harold Lee wrote: > >> Regarding this JDK bug: > >> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6403933 > >> > >> I think we are experiencing this using HttpCore on Linux with Java > >> 1.6. We wind up leaking socket descriptors until the JVM process runs > >> out. We also wind up having to start a new reactor thread, which > >> creates a new Selector. The old reactor thread keeps running and the > >> thread dump shows it in sun.nio.ch.EPollArrayWrapper.epollWait as > >> reported by others in the bug report above. > >> > > Hi Harold Did you have any luck reproducing the problem? I put together a work-around for the bug that causes the epoll spin problem [1]. If you are interested in trying it out I will happily share it with you. The work-around is pretty ugly, so I want to be sure there is no other way of solving the issue. cheers Oleg [1] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6403933 > > Folks > > > > Anyone experienced anything like that? The looks pretty old, but there > > has been no reports of similar problems with HttpCore NIO. I am using > > Linux / JDK 1.6 on a daily basis when hacking on HttpCore but I have not > > encountered such a problem yet. > > > > > >> Here's the change that the Glassfish team made to work around this JDK bug: > >> > >> http://fisheye5.cenqua.com/browse/glassfish/appserv-http-engine/src/java/com/sun/enterprise/web/connector/grizzly/ByteBufferInputStream.java?r1=1.8&r2=1.9 > >> > >> From my reading, the Glassfish code is much simpler than the HttpCore > >> NIO code: they're registering interest for just 1 socket and using > >> Selector.select() to wait for data from that socket. For HttpCore NIO, > >> it isn't yet clear to me how we can detect which selector is "trashed" > >> in order to cancel it and recreate it. > >> > >> I'm working on a workaround in AbstractMultiworkerIOReactor.java. If > >> selector.select returns 0 (setting readyCount to 0) then we don't know > >> whether this bug hit us or we just had a timeout. > > > > The problem is that it is perfectly valid for a selector to return 0 > > ready count. This condition alone is not sufficient to assume the > > selector is trashed. > > > > > >> To be safe, I think > >> we need to close every registered SelectorKey and then call > >> selector.selectNow() to flush them. Then we can create a new > >> SelectorKey for each and reregister them. The only way to make it less > >> common, I think, is to use a long selectTimeout value so that the odds > >> of a timeout are low. Ugly, but I hope it will work. > >> > > > > This will unfortunately screw up handling of new / closed channels as > > well timeout logic. > > > > The work-around looks butt ugly and would require tons of fairly complex > > code. Is there a way to reproduce the issue with a test scenario, so we > > could look for alternative approaches? > > > > Cheers > > > > Oleg > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@hc.apache.org > For additional commands, e-mail: dev-h...@hc.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@hc.apache.org For additional commands, e-mail: dev-h...@hc.apache.org
