Re: Memory Usage - Tomcat 5.0.25
Nandish Rudra wrote: Hello Everyone, I am writing about this error from yesterday. I used JProfiler to monitor my memory usage. And am now sure that each and every static object is trashed when the application is undeployed and the profiler shows that memory is free and all instance of the objects are GC'd. This works on a Windows 2000 setup of Tomcat 5.0.25 with Java 2 SDK version 1.4.2_04 and Ant 1.6.1, but fails miserably on GNU Linux 2.4.20-8 setup. this happens with both tomcat 5.0.25 and 5.0.27 Any ideas why something like this could be happening. Nandish Rudra ECI Conference call Service LLC. -Original Message- From: Shapira, Yoav [mailto:[EMAIL PROTECTED] Sent: Monday, August 09, 2004 1:35 PM To: Tomcat Users List Subject: RE: Memory Usage - Tomcat 5.0.25 Hi, I have a couple of ideas. One is that your webapp maintain static or shared references to objects that prevent them from being garbage collected, and therefore memory from returning to the heap. Another is that a webapp undeploy is not guaranteed to reclaim all memory used by the webapp anyways so to count on this behavior is not smart. It is expected that every time you reload your webapp the overall memory usage of the server will go up a bit, as not all objects are gone (for example, if you have a static reference than the old classloader and anything that references it strongly will remain in memory). Yoav Shapira Millennium Research Informatics -Original Message- From: Nandish Rudra [mailto:[EMAIL PROTECTED] Sent: Monday, August 09, 2004 1:17 PM To: Tomcat Users List (E-mail) Subject: Memory Usage - Tomcat 5.0.25 Hello, I am having some memory issues while deploing/undeploying web applications to Tomcat. I am using Tomcat 5.0.25 with Java 2 SDK version 1.4.2_04 and Ant 1.6.1 on GNU Linux 2.4.20-8. I use ant to compile my web application and Tomcat's catalina-ant.jar to deploy it automatically. Here is my problem. When I undeploy/remove an application, Tomcat does not reclaim the memory being used by the web application and when the application is re-deployed/re-installed a significant increase in memory is seen. This increase is obviously the memory usage by the new instance of the web application. Does anyone have any idea as to why this is happening? Try looking at jvmstat (http://developers.sun.com/dev/coolstuff/jvmstat/) My own tests with show that its the permanent space of objects that gets filled up and not reclaimed after each reload. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Memory Usage - Tomcat 5.0.25
Hi, LONG-snip / Does anyone have any idea as to why this is happening? Try looking at jvmstat (http://developers.sun.com/dev/coolstuff/jvmstat/) My own tests with show that its the permanent space of objects that gets filled up and not reclaimed after each reload. Yup, that's as expected. Yoav Shapira - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Memory Usage - Tomcat 5.0.25
Hi, I have a couple of ideas. One is that your webapp maintain static or shared references to objects that prevent them from being garbage collected, and therefore memory from returning to the heap. Another is that a webapp undeploy is not guaranteed to reclaim all memory used by the webapp anyways so to count on this behavior is not smart. It is expected that every time you reload your webapp the overall memory usage of the server will go up a bit, as not all objects are gone (for example, if you have a static reference than the old classloader and anything that references it strongly will remain in memory). Yoav Shapira Millennium Research Informatics -Original Message- From: Nandish Rudra [mailto:[EMAIL PROTECTED] Sent: Monday, August 09, 2004 1:17 PM To: Tomcat Users List (E-mail) Subject: Memory Usage - Tomcat 5.0.25 Hello, I am having some memory issues while deploing/undeploying web applications to Tomcat. I am using Tomcat 5.0.25 with Java 2 SDK version 1.4.2_04 and Ant 1.6.1 on GNU Linux 2.4.20-8. I use ant to compile my web application and Tomcat's catalina-ant.jar to deploy it automatically. Here is my problem. When I undeploy/remove an application, Tomcat does not reclaim the memory being used by the web application and when the application is re-deployed/re-installed a significant increase in memory is seen. This increase is obviously the memory usage by the new instance of the web application. Does anyone have any idea as to why this is happening? Regards, NR - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. This e-mail is intended only for the individual(s) to whom it is addressed, and may not be saved, copied, printed, disclosed or used by anyone else. If you are not the(an) intended recipient, please immediately delete this e-mail from your computer system and notify the sender. Thank you. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Memory Usage - Tomcat 5.0.25
Hello Yaov, You are correct I do have a few static varibles that point to running threads and some other objects. When the application is shutdown I ensure that each thread is destroyed and all static varibales are set to null, including thread identifiers, this should let my call to GC clear the memory. You are also right in saying that i should not depend on undeploy to reclaim all memory that the webapp was using, and I don't. Like I mentioned I do make sure all static variables get set to null before the application shuts down. It would be understandable if not all memory utilized by the webapp is reclaimed, but in my case absolutely no memory is being reclaimed. For example, say, i start tomcat and it starts with 30M initial memory usage without the application. Now when i deploy the application the size jumps by 8M to 38M. As the app is undeploy and re-deploy the memory usage jumps from 38M to 46-47M. Now this, if I am not wrong, is not how things should be. I would appreciate anymore suggestion that you or anyone may have. Regards, Nandish -Original Message- From: Shapira, Yoav [mailto:[EMAIL PROTECTED] Sent: Monday, August 09, 2004 1:35 PM To: Tomcat Users List Subject: RE: Memory Usage - Tomcat 5.0.25 Hi, I have a couple of ideas. One is that your webapp maintain static or shared references to objects that prevent them from being garbage collected, and therefore memory from returning to the heap. Another is that a webapp undeploy is not guaranteed to reclaim all memory used by the webapp anyways so to count on this behavior is not smart. It is expected that every time you reload your webapp the overall memory usage of the server will go up a bit, as not all objects are gone (for example, if you have a static reference than the old classloader and anything that references it strongly will remain in memory). Yoav Shapira Millennium Research Informatics -Original Message- From: Nandish Rudra [mailto:[EMAIL PROTECTED] Sent: Monday, August 09, 2004 1:17 PM To: Tomcat Users List (E-mail) Subject: Memory Usage - Tomcat 5.0.25 Hello, I am having some memory issues while deploing/undeploying web applications to Tomcat. I am using Tomcat 5.0.25 with Java 2 SDK version 1.4.2_04 and Ant 1.6.1 on GNU Linux 2.4.20-8. I use ant to compile my web application and Tomcat's catalina-ant.jar to deploy it automatically. Here is my problem. When I undeploy/remove an application, Tomcat does not reclaim the memory being used by the web application and when the application is re-deployed/re-installed a significant increase in memory is seen. This increase is obviously the memory usage by the new instance of the web application. Does anyone have any idea as to why this is happening? Regards, NR - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. This e-mail is intended only for the individual(s) to whom it is addressed, and may not be saved, copied, printed, disclosed or used by anyone else. If you are not the(an) intended recipient, please immediately delete this e-mail from your computer system and notify the sender. Thank you. - 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]
