Betr.: RE: Memory Management between different webapps
The problem we are confronted with: all our web-apps are running fine in our test-environment, even if workload is simulated to be very high. If we go to production environment (which is an exact copy of the test-environment) then tomcat gives OOME, sometimes 3-4 times a day. And it looks to be at random situations, so it's a really big mistery why in test everything goes well and in production it crashes more then once a day. And it's doing it for approx 4 months now, so it's time it's getting solved. [EMAIL PROTECTED] 2/02/2006 11:06 From: Roel De Nijs [mailto:[EMAIL PROTECTED] I have a tomcat with ± 10 web-applications. Is there a maximum or some guidance in the number of web-apps you can put in one instance of Tomcat? Tomcat itself uses relatively little memory per-webapp (a few megabytes, depending on version). The major load comes from the number of simultaneous connections (and hence the size of the thread pool) and, even more, from how the webapps are written. You're in the best place to evaluate these. And i start tomcat with the options -Xmx1024m -Xms1024m -- is there some information or articles about how tomcat is spreading all this memory over the web-apps? Is this completely random, or first come first gets? What if a web-app is called for the first time and all possible memory is allocated to other web-apps? It's all one big object memory, shared between all the webapps. Roughly (there are many more nuances than this): whenever it gets full, the garbage-collector is run. If there's not enough space to allocate an object after the garbage collector has run, you get an OutOfMemoryError. So memory will be allocated as your webapps request it (and potentially returned to the Java VM's pool of free memory some unknown time after they stop using it); if a webapp is called for the first time and there's not enough space to allocate the memory required for its startup, you'll get an OOME. To my knowledge, there is no way of partitioning memory inside a single JVM such that the amount available to a given webapp can be restricted. - Peter - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] ** Disclaimer: zie www.aquafin.be
Re: Betr.: RE: Memory Management between different webapps
Obviously something is different. Given tomcat and the web-app are the same, I would guess environmental differences exist between test and production. Do both have the same set of services? Same OS? OOM errors can also indicate a lack of system resources such as file handles. Just throwing out some ideas to look in to. -- David Roel De Nijs wrote: The problem we are confronted with: all our web-apps are running fine in our test-environment, even if workload is simulated to be very high. If we go to production environment (which is an exact copy of the test-environment) then tomcat gives OOME, sometimes 3-4 times a day. And it looks to be at random situations, so it's a really big mistery why in test everything goes well and in production it crashes more then once a day. And it's doing it for approx 4 months now, so it's time it's getting solved. [EMAIL PROTECTED] 2/02/2006 11:06 From: Roel De Nijs [mailto:[EMAIL PROTECTED] I have a tomcat with ± 10 web-applications. Is there a maximum or some guidance in the number of web-apps you can put in one instance of Tomcat? Tomcat itself uses relatively little memory per-webapp (a few megabytes, depending on version). The major load comes from the number of simultaneous connections (and hence the size of the thread pool) and, even more, from how the webapps are written. You're in the best place to evaluate these. And i start tomcat with the options -Xmx1024m -Xms1024m -- is there some information or articles about how tomcat is spreading all this memory over the web-apps? Is this completely random, or first come first gets? What if a web-app is called for the first time and all possible memory is allocated to other web-apps? It's all one big object memory, shared between all the webapps. Roughly (there are many more nuances than this): whenever it gets full, the garbage-collector is run. If there's not enough space to allocate an object after the garbage collector has run, you get an OutOfMemoryError. So memory will be allocated as your webapps request it (and potentially returned to the Java VM's pool of free memory some unknown time after they stop using it); if a webapp is called for the first time and there's not enough space to allocate the memory required for its startup, you'll get an OOME. To my knowledge, there is no way of partitioning memory inside a single JVM such that the amount available to a given webapp can be restricted. - Peter - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] ** Disclaimer: zie www.aquafin.be - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Betr.: RE: Memory Management between different webapps
From: Roel De Nijs [mailto:[EMAIL PROTECTED] Subject: Betr.: RE: Memory Management between different webapps The problem we are confronted with: all our web-apps are running fine in our test-environment, even if workload is simulated to be very high. If we go to production environment (which is an exact copy of the test-environment) then tomcat gives OOME, sometimes 3-4 times a day. Have you read this? http://tomcat.apache.org/faq/memory.html Note that an OOME can result from a variety of problems other than exhausting heap memory, including such things as running out of file descriptors. Turn on -verbose:gc to get an idea of what's happening with the Java heap, and proceed from there. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
