Re: Perm Gen not being released in GC
This has been discussed quite a lot on mailing list. Lots of things can generate memory leaks in webapp environment. Amongst others: - not nullifying threadlocal variable. - use of singleton pattern - some bugged versions of CGlib take a look at older messages in this mailing list http://marc.theaimsgroup.com/?l=tomcat-userw=2r=1s=permgenq=b Darren Kukulka a écrit : Hi All, Throughput Garbage collection on a 5.5.15 Tomcat instance is failing to release Old Gen heap space when it becomes full on one of our Windows installations. For the most part GC does release memory - in a typical working day this is an upward trend in terms of the amount of heap reclaimed, gradually becoming a downward trend late in the day. Every now and then JConsole shows Old Gen as having flat-lined. Only a Tomcat restart can rectify the problem. Killing sessions followed by a manual GC does not seem to have an effect. Haven't yet determined whether we need to start looking at the young to old heap allocation ratios - is this the main area I should be looking into? Any thoughts would be appreciated. Cheers, Darren Kukulka Connaught honoured AIM 'Decade of Excellence' Award Connaught awarded Partnering Contractor of the Year 2005 Connaught wins AIM 'Company of the Year' award 2004 West of England Business of the Year Award Winner 2003 Why not visit our website http://www.connaught.plc.uk Disclaimer: The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete this message. Connaught plc, Head Office 01392 444546 - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Perm Gen not being released in GC
Hi All, Throughput Garbage collection on a 5.5.15 Tomcat instance is failing to release Old Gen heap space when it becomes full on one of our Windows installations. For the most part GC does release memory - in a typical working day this is an upward trend in terms of the amount of heap reclaimed, gradually becoming a downward trend late in the day. Every now and then JConsole shows Old Gen as having flat-lined. Only a Tomcat restart can rectify the problem. Killing sessions followed by a manual GC does not seem to have an effect. Haven't yet determined whether we need to start looking at the young to old heap allocation ratios - is this the main area I should be looking into? Any thoughts would be appreciated. Cheers, Darren Kukulka Connaught honoured AIM 'Decade of Excellence' Award Connaught awarded Partnering Contractor of the Year 2005 Connaught wins AIM 'Company of the Year' award 2004 West of England Business of the Year Award Winner 2003 Why not visit our website http://www.connaught.plc.uk Disclaimer: The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete this message. Connaught plc, Head Office 01392 444546
Re: Perm Gen not being released in GC
Darren, Every now and then JConsole shows Old Gen as having flat-lined. Only a Tomcat restart can rectify the problem. Killing sessions followed by a manual GC does not seem to have an effect. Haven't yet determined whether we need to start looking at the young to old heap allocation ratios - is this the main area I should be looking into? We see this same behavior. I too am interested in comments from others. We are running on a OS X Server; JVM v1.5. Stephen Caine Soft Breeze Systems, LLC - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Perm Gen not being released in GC
Hi Stephanie, Im a Project Manager, not a techie but we had the same problem and had to increase the perm gen to the following: Tomcat sets it at default at 64MB. Perm Gen Memory: 150 MB Max Perm Gen: 256 MB We where getting perm gen out of memory errors which is why we did this. This stabilised the environment but we still have problems with our Heap Memory filling up and not been garbage collected properly. Kind Regards Adrena Keating EDS Project Manager, ABN AMRO NL Solution Centre Tel: +31-20-6299038 Mobile: +31-6-22574953 Stephen Caine [EMAIL PROTECTED] To: Tomcat Users List users@tomcat.apache.org rnd.com cc: Subject: Re: Perm Gen not being released in GC 09/15/2006 05:31 PM Please respond to Tomcat Users List Darren, Every now and then JConsole shows Old Gen as having flat-lined. Only a Tomcat restart can rectify the problem. Killing sessions followed by a manual GC does not seem to have an effect. Haven't yet determined whether we need to start looking at the young to old heap allocation ratios - is this the main area I should be looking into? We see this same behavior. I too am interested in comments from others. We are running on a OS X Server; JVM v1.5. Stephen Caine Soft Breeze Systems, LLC - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --- This message (including any attachments) is confidential and may be privileged. If you have received it by mistake please notify the sender by return e-mail and delete this message from your system. Any unauthorised use or dissemination of this message in whole or in part is strictly prohibited. Please note that e-mails are susceptible to change. ABN AMRO Bank N.V, which has its seat at Amsterdam, the Netherlands, and is registered in the Commercial Register under number 33002587, including its group companies, shall not be liable for the improper or incomplete transmission of the information contained in this communication nor for any delay in its receipt or damage to your system. ABN AMRO Bank N.V. (or its group companies) does not guarantee that the integrity of this communication has been maintained nor that this communication is free of viruses, interceptions or interference. --- - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Perm Gen not being released in GC
Are you sure you don't have a memory leak? FWIW, I had a client with a situation like this, we wound up throwing in a stopgap that consisted of a thread that checked free space once a minute and explicitly invoked System.gc() if certain parameters were met. Not the solution I originally proposed, but it was something I could do in one day (the length of my contract) and it was cheaper than buying a heap analyzer (a la JProbe). --- Tracy Nelson / Nelnet Business Solutions 402 / 617-9449 | -Original Message- | From: Darren Kukulka [mailto:[EMAIL PROTECTED] | Sent: Friday, 15 September, 2006 09:59 | To: Tomcat Users List | Subject: Perm Gen not being released in GC | | Hi All, | | | | Throughput Garbage collection on a 5.5.15 Tomcat instance is failing to | release Old Gen heap space when it becomes full on one of our Windows | installations. | | | | For the most part GC does release memory - in a typical working day this | is | an upward trend in terms of the amount of heap reclaimed, gradually | becoming | a downward trend late in the day. | | | | Every now and then JConsole shows Old Gen as having flat-lined. Only a | Tomcat restart can rectify the problem. Killing sessions followed by a | manual GC does not seem to have an effect. | | | | Haven't yet determined whether we need to start looking at the young to | old | heap allocation ratios - is this the main area I should be looking into? | | | | Any thoughts would be appreciated. | | | | Cheers, | | Darren Kukulka | | | | | | Connaught honoured AIM 'Decade of Excellence' Award | | | | Connaught awarded Partnering Contractor of the Year 2005 | | | | Connaught wins AIM 'Company of the Year' award 2004 | | | | West of England Business of the Year Award Winner 2003 | | | | Why not visit our website http://www.connaught.plc.uk | | | | Disclaimer: | | The information transmitted is intended only for the person or entity to | which it is addressed and may contain confidential and/or privileged | material. Any review, retransmission, dissemination or other use of, or | taking of any action in reliance upon, this information by persons or | entities other than the intended recipient is prohibited. If you received | this in error, please contact the sender and delete this message. | | | | Connaught plc, Head Office 01392 444546 - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Perm Gen not being released in GC
Im a Project Manager, not a techie but we had the same problem and had to increase the perm gen to the following: Tomcat sets it at default at 64MB. Perm Gen Memory: 150 MB Max Perm Gen: 256 MB Perm gen is memory reserved for class loading and is directly proportional to the number/size of classes you load. We where getting perm gen out of memory errors which is why we did this. This stabilised the environment but we still have problems with our Heap Memory filling up and not been garbage collected properly. That sounds like a memory leak. Nix. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
