On Fri, Mar 9, 2012 at 9:16 PM, Christopher Schultz < ch...@christopherschultz.net> wrote:
> -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Doron, > > On 3/9/12 12:19 PM, Doron Tsur wrote: > > Tomcat: 7 latest Java: 1.6.25 OS: Windows Server 2003 R2 SP2 > > qballer: sorry. Java 1.6.0_25 tomcat 7.0.23 > > 1. What specific version of Tomcat 7? > 2. 1.6.25 is not a version of Java that I know of. Real version number > and vendor, please? > > > This is a production server that uses high bandwidth. Poking > > around Poolmon.exe I was able to find that > > > > 1. the AfdP tag is consuming a lot of NP (Non Paged) pool. > > What is "the AdfP tag"? > > qballer: ancillary function driver it's a Win Socket driver > > > 2. This is a tag concerning the windows socket driver (afd.sys). > > Googling for "afd non-paged pool exhaustion" comes up with lots of > hits. Have you read them? > > qballer: Yes I have. > > Many seem to suggest that certain connections are left open for a very > long time. Are you using long-lasting connections with KEEPALIVE > enabled? If so, it's possible that it could be causing this problem. > > > We have many production servers running our tomcat. We have only > > encountered this issue in two of them, those servers have the same > > OS/Java/Tomcat installed. One server uses high bandwidth and the > > other uses much less. > > Obviously, the question is: what is different about these two servers? > If this was a problem with Tomcat itself, the JVM, or even the seevice > configuration, I would expect it to happen everywhere. Given that it > doesn't happen everywhere, I would suspect something at a lower-level. > Do all servers have identical OS images on them, and are they all at > the same patch-level? > > Not the same images, that is why i suspect it's outside of tomcat. > > I say tomcat because this is the process that consumes all NP pool > > (about 170MB). > > > > 1. Have you ever encountered this issue? 2. Do you know of any > > application level/Tomcat configuration work around to solve this > > issue? > > None that I know of. Perhaps you could adjust some of the fine-grained > socket-configuration bits, but I wouldn't start fiddling without a > very good idea about what you are doing. It's even possible that > Tomcat does not support configuration of whatever specific socket bits > you need to fiddle. If that turns out to be the problem, it's fairly > easy to add configuration options. > > > 3. Do you think that there is something wrong in the way Tomcat > > interfaces with winsock? > > Tomcat does not interface at all with winsock unless you are using > APR. Are you using APR? That would seem like a good thing to tell us. > > qballer: Nope not using APR. > > 4. Do you believe that Tomcat APR might resolve this issue? > > If anything, I would say that APR might even make the problem worse. > On the other hand, it's fairly easy to try it: just drop the .dlls in > the right place and restart. As long as you haven't changed Tomcat > from the default configuration, it will use APR for your HTTP connectors. > > > 5. I can't seem to download this hotfix to further investigate > > these files, they might contain a suitable version. Do you know how > > can I get them? > > What hotfix are you talking about? > > Sorry ignore the hotfix part, I've checked that direction and it's a dead end. > > When Tomcat is killed the Non Paged Pool doesn't return to the OS. > > How do you "kill" Tomcat? Does the JVM process shut down entirely? If > it does, then your problem should lie elsewhere: once the process is > dead, all memory should be released. If that's not happening, there is > either a horrible bug in the OS or you are misinterpreting your > observations. > > Yes it does shut down, NPP doesn't get returned to the OS. That is why i think there is a driver code in the way. > - -chris > -----BEGIN PGP SIGNATURE----- > Version: GnuPG/MacGPG2 v2.0.17 (Darwin) > Comment: GPGTools - http://gpgtools.org > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iEYEARECAAYFAk9aVxcACgkQ9CaO5/Lv0PCFhwCgmgy9A1mrFg4Me1lHp674i5pf > jjMAnipMogXefj0ezYhJNs1WSJb13V3F > =XtAE > -----END PGP SIGNATURE----- > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
