This seems to be fixed by a newer version of the JRE, i.e. java version "1.6.0" Java(TM) SE Runtime Environment (build 1.6.0-b105) Java HotSpot(TM) 64-Bit Server VM (build 1.6.0-b105, mixed mode)
So I think that you can avoid the tricky workaround. Thank you for your time and attention. Harold On Sat, Jul 31, 2010 at 7:11 AM, Oleg Kalnichevski <[email protected]> wrote: > 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 <[email protected]> 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: [email protected] >> For additional commands, e-mail: [email protected] >> >> > > > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
