Re: TOMCAT GC Issue
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Paulwintech, On 1/21/2010 2:00 AM, Paulwintech wrote: I am really sorry it was my typo mistake its 10 second not 10 mins =^D. You didn't say what type of hardware you're using, but 10 seconds of (concurrent) GC activity it not particularly troubling to me. It seems a bit on the long side, but if you're running on a single-processor 200MHz machine, maybe it's simply necessary. Please let me know what are the logs you are looking for accordingly i will send. Verbose GC will log to stderr, which generally goes to stdout.log on *NIX. You never told us about your environment, so I can't really help you, here. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAktYcZ8ACgkQ9CaO5/Lv0PCkcwCfUslWTTG4N5RlQ3rU25wLw92a gBgAn2hxRZ8TXRmkC7/EDSIqOfv9jlfZ =g6ly -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: TOMCAT GC Issue
2010/1/20 Paulwintech paulwint...@gmail.com Hello, I am new to the Tomcat Administration, I have some 4 production servers running Tomcat6.x with Jdk - To monitor all my applications like Apache,Tomcat and Mysql we are using OPmanager-Application manager tool. Intermediately i get GC critical alert. That means some times GC collection goes high and remains for more than 10 mins. Then it clears the Grabage. But this is happening recently checked all possible logs found nothing. This is not happening every time, Say like twice in a day... Could you give us a bit more information? + JDK version? + What memory and GC settings are set? + Does the alert coincide with high usage on the servers? + Does it happen on all servers equally? If not, what factors differ between the servers? + *Exactly* what condition causes the monitor to report the alert? Feel free to point us at the web page describing the alert's definition in the monitor. Sorry to ask for that lot, but different Java versions can handle GC very differently, and the options make a difference too. - Peter
RE: TOMCAT GC Issue
I agree with Peter, we need more information. I will point out that we had a similar issue - during peak activity on our site, and it related to sessions being created faster than Tomcat could get rid of them (even though they were expired already). We used the /manager/html app that comes with Tomcat (you have to leave the '/manager' webapp installed) to view the number of sessions - and noticed that they were growing exponentially during our peak loads. Also, if you are clustered, remember that your sessions are being replicated across all 4 Tomcats - so 1/4 of the load on each server will fill up the heap space as fast as 4X load on 1 server would... Check your heap size (-Xmx=? in your 'catalina.sh' or 'catalina.bat' file)... As Peter mentioned, that will be necessary to figure out what the problem is. -- Robin D. Wilson Director of Web Development KingsIsle Entertainment, Inc. CELL: 512-426-3929 DESK: 512-623-5913 www.KingsIsle.com -Original Message- From: peter.crowth...@googlemail.com [mailto:peter.crowth...@googlemail.com] On Behalf Of Peter Crowther Sent: Wednesday, January 20, 2010 4:58 AM To: Tomcat Users List Subject: Re: TOMCAT GC Issue 2010/1/20 Paulwintech paulwint...@gmail.com Hello, I am new to the Tomcat Administration, I have some 4 production servers running Tomcat6.x with Jdk - To monitor all my applications like Apache,Tomcat and Mysql we are using OPmanager-Application manager tool. Intermediately i get GC critical alert. That means some times GC collection goes high and remains for more than 10 mins. Then it clears the Grabage. But this is happening recently checked all possible logs found nothing. This is not happening every time, Say like twice in a day... Could you give us a bit more information? + JDK version? + What memory and GC settings are set? + Does the alert coincide with high usage on the servers? + Does it happen on all servers equally? If not, what factors differ between the servers? + *Exactly* what condition causes the monitor to report the alert? Feel free to point us at the web page describing the alert's definition in the monitor. Sorry to ask for that lot, but different Java versions can handle GC very differently, and the options make a difference too. - Peter - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: TOMCAT GC Issue
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Paulwintech, On 1/20/2010 5:48 AM, Paulwintech wrote: Intermediately i get GC critical alert. That means some times GC collection goes high and remains for more than 10 mins. Then it clears the Grabage. But this is happening recently checked all possible logs found nothing. This is not happening every time, Say like twice in a day... I would enable verbose garbage collection to verify what your instrumentation is telling you. You can enable verbose GC using this command-line flag: - -verbose:gc or - -XX:+PrintGCDetails and -XX:+PrintGCTimeStamps If you are able to post relevant portions of the GC log along with any other information you provide, it will certainly be helpful. A 10-minute-long GC run? That sounds disastrous. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAktXVoIACgkQ9CaO5/Lv0PBHugCZAYKdm4b0rLLsPDRUxXPIr4sU FqYAoKiUL+CjKGXm+/A9UtuCG9KCnG2s =9/YG -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: TOMCAT GC Issue
Hi, I am really sorry it was my typo mistake its 10 second not 10 mins =^D. Please let me know what are the logs you are looking for accordingly i will send. Thanks Paulwintech Christopher Schultz-2 wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Paulwintech, On 1/20/2010 5:48 AM, Paulwintech wrote: Intermediately i get GC critical alert. That means some times GC collection goes high and remains for more than 10 mins. Then it clears the Grabage. But this is happening recently checked all possible logs found nothing. This is not happening every time, Say like twice in a day... I would enable verbose garbage collection to verify what your instrumentation is telling you. You can enable verbose GC using this command-line flag: - -verbose:gc or - -XX:+PrintGCDetails and -XX:+PrintGCTimeStamps If you are able to post relevant portions of the GC log along with any other information you provide, it will certainly be helpful. A 10-minute-long GC run? That sounds disastrous. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAktXVoIACgkQ9CaO5/Lv0PBHugCZAYKdm4b0rLLsPDRUxXPIr4sU FqYAoKiUL+CjKGXm+/A9UtuCG9KCnG2s =9/YG -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org -- View this message in context: http://old.nabble.com/TOMCAT-GC-Issue-tp27239776p27253657.html Sent from the Tomcat - User mailing list archive at Nabble.com. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
