RE : Threads issues in Tomcat 5.0.28
2. you can use kill -3 command to dump the thread stack and execute the same command few seconds later. You obtain two stack trace that you can compare to identify the potential source of inativity. -Message d'origine- De : Matt Robinson [mailto:[EMAIL PROTECTED] Envoyé : mercredi 8 décembre 2004 03:32 À : [EMAIL PROTECTED] Objet : Threads issues in Tomcat 5.0.28 Hi, We have 5 instances of Tomcat 5.0.28 running on their own high performance servers (dual XEON / 2GB RAM, etc) receiving AJP13 connector requests via our main web server which has IIS 5, IIS redirector, and Tomcat4. This works great even under high loads except for one thing: after several hours of usage (could be 3 hours or up 24 hours), the number of Tomcat threads on the 5.0.28 systems will suddenly increase at a rapid rate until Tomcat no longer responds to requests. It will hit the max # threads (which defaults to 200) and essentially freeze until it is restarted. This is strange because this behavior does not seem to correspond to increased usage of the particular server it occurs on. We are not sure what is triggering this and what those Tomcat threads are waiting on [they remain busy, waiting and unable to be reused by Tomcat]. My questions are: 1. Has anyone else experienced this kind of Thread explosion problem? 2. Is there a way to find out exactly what each Tomcat Thread is doing/waiting for? 3. Is there a way to periodically clear Tomcat's threadpool -- i.e. get rid of waiting/busy/unusued threads. We are working on ways to automatically restart Tomcat once a certain # of threads is reached, but this is not an acceptable solution, only a temporary workaround of course. Many thanks in advance __ Do you Yahoo!? Take Yahoo! Mail with you! Get it on your mobile phone. http://mobile.yahoo.com/maildemo - 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]
RE: Threads issues in Tomcat 5.0.28
Hi, Once you get the thread dump, post it, and we can try to help you figure out what's wrong. The Tomcat thread pools should automatically recover unused threads, subject to your configuration (see the maxSpareThreads and releated Connector configuration attributes). Yoav Shapira http://www.yoavshapira.com -Original Message- From: Arnab Chakravarty [mailto:[EMAIL PROTECTED] Sent: Tuesday, December 07, 2004 10:50 PM To: Tomcat Users List Subject: RE: Threads issues in Tomcat 5.0.28 Hey, I see your problem similar to mine some time in the past. What you need to is the following: - Lower the number of threads and keep it close to 120-150 threads. - Are you using a database, if yes, check if the DB connection pool is the bottleneck - Yes, you can find what the 200 threads are doing by taking a threaddump. The way to do this is to use the command - kill -QUIT tomcat pid. Hope this helps. Arnab -Original Message- From: Matt Robinson [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 08, 2004 8:02 AM To: [EMAIL PROTECTED] Subject: Threads issues in Tomcat 5.0.28 Hi, We have 5 instances of Tomcat 5.0.28 running on their own high performance servers (dual XEON / 2GB RAM, etc) receiving AJP13 connector requests via our main web server which has IIS 5, IIS redirector, and Tomcat4. This works great even under high loads except for one thing: after several hours of usage (could be 3 hours or up 24 hours), the number of Tomcat threads on the 5.0.28 systems will suddenly increase at a rapid rate until Tomcat no longer responds to requests. It will hit the max # threads (which defaults to 200) and essentially freeze until it is restarted. This is strange because this behavior does not seem to correspond to increased usage of the particular server it occurs on. We are not sure what is triggering this and what those Tomcat threads are waiting on [they remain busy, waiting and unable to be reused by Tomcat]. My questions are: 1. Has anyone else experienced this kind of Thread explosion problem? 2. Is there a way to find out exactly what each Tomcat Thread is doing/waiting for? 3. Is there a way to periodically clear Tomcat's threadpool -- i.e. get rid of waiting/busy/unusued threads. We are working on ways to automatically restart Tomcat once a certain # of threads is reached, but this is not an acceptable solution, only a temporary workaround of course. Many thanks in advance __ Do you Yahoo!? Take Yahoo! Mail with you! Get it on your mobile phone. http://mobile.yahoo.com/maildemo - 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] 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: Threads issues in Tomcat 5.0.28
Hi Yoav, Thanks for the response I will be sure to include my Thread dump. Meanwhile it sames that AJP13 in Tomcat5 has no parameters such as maxSpareThreads, maxThreads, etc. We are using AJP13 to handle all requests... The documentation (and all searches I have done) do not mention the ability to use these parameters with AJP13, but they can be used with the HTTP protocol. Anybody have any idea whether AJP13 supports these attributes in Tomcat 5.0? Thanks again, Matt --- Shapira, Yoav [EMAIL PROTECTED] wrote: Hi, Once you get the thread dump, post it, and we can try to help you figure out what's wrong. The Tomcat thread pools should automatically recover unused threads, subject to your configuration (see the maxSpareThreads and releated Connector configuration attributes). Yoav Shapira http://www.yoavshapira.com -Original Message- From: Arnab Chakravarty [mailto:[EMAIL PROTECTED] Sent: Tuesday, December 07, 2004 10:50 PM To: Tomcat Users List Subject: RE: Threads issues in Tomcat 5.0.28 Hey, I see your problem similar to mine some time in the past. What you need to is the following: - Lower the number of threads and keep it close to 120-150 threads. - Are you using a database, if yes, check if the DB connection pool is the bottleneck - Yes, you can find what the 200 threads are doing by taking a threaddump. The way to do this is to use the command - kill -QUIT tomcat pid. Hope this helps. Arnab -Original Message- From: Matt Robinson [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 08, 2004 8:02 AM To: [EMAIL PROTECTED] Subject: Threads issues in Tomcat 5.0.28 Hi, We have 5 instances of Tomcat 5.0.28 running on their own high performance servers (dual XEON / 2GB RAM, etc) receiving AJP13 connector requests via our main web server which has IIS 5, IIS redirector, and Tomcat4. This works great even under high loads except for one thing: after several hours of usage (could be 3 hours or up 24 hours), the number of Tomcat threads on the 5.0.28 systems will suddenly increase at a rapid rate until Tomcat no longer responds to requests. It will hit the max # threads (which defaults to 200) and essentially freeze until it is restarted. This is strange because this behavior does not seem to correspond to increased usage of the particular server it occurs on. We are not sure what is triggering this and what those Tomcat threads are waiting on [they remain busy, waiting and unable to be reused by Tomcat]. My questions are: 1. Has anyone else experienced this kind of Thread explosion problem? 2. Is there a way to find out exactly what each Tomcat Thread is doing/waiting for? 3. Is there a way to periodically clear Tomcat's threadpool -- i.e. get rid of waiting/busy/unusued threads. We are working on ways to automatically restart Tomcat once a certain # of threads is reached, but this is not an acceptable solution, only a temporary workaround of course. Many thanks in advance __ Do you Yahoo!? Take Yahoo! Mail with you! Get it on your mobile phone. http://mobile.yahoo.com/maildemo - 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] 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] __ Do you Yahoo!? All your favorites on one personal page Try My Yahoo! http://my.yahoo.com - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Threads issues in Tomcat 5.0.28
Hey, The connector tag in the server.xml where you mention the port for ajp13 is the place where you should specify the thread configuration. You can find more information here: http://jakarta.apache.org/tomcat/tomcat-5.0-doc/config/ajp.html Hope it helps. Arnab -Original Message- From: Matt Robinson [mailto:[EMAIL PROTECTED] Sent: Thursday, December 09, 2004 2:29 AM To: Tomcat Users List Subject: RE: Threads issues in Tomcat 5.0.28 Hi Yoav, Thanks for the response I will be sure to include my Thread dump. Meanwhile it sames that AJP13 in Tomcat5 has no parameters such as maxSpareThreads, maxThreads, etc. We are using AJP13 to handle all requests... The documentation (and all searches I have done) do not mention the ability to use these parameters with AJP13, but they can be used with the HTTP protocol. Anybody have any idea whether AJP13 supports these attributes in Tomcat 5.0? Thanks again, Matt --- Shapira, Yoav [EMAIL PROTECTED] wrote: Hi, Once you get the thread dump, post it, and we can try to help you figure out what's wrong. The Tomcat thread pools should automatically recover unused threads, subject to your configuration (see the maxSpareThreads and releated Connector configuration attributes). Yoav Shapira http://www.yoavshapira.com -Original Message- From: Arnab Chakravarty [mailto:[EMAIL PROTECTED] Sent: Tuesday, December 07, 2004 10:50 PM To: Tomcat Users List Subject: RE: Threads issues in Tomcat 5.0.28 Hey, I see your problem similar to mine some time in the past. What you need to is the following: - Lower the number of threads and keep it close to 120-150 threads. - Are you using a database, if yes, check if the DB connection pool is the bottleneck - Yes, you can find what the 200 threads are doing by taking a threaddump. The way to do this is to use the command - kill -QUIT tomcat pid. Hope this helps. Arnab -Original Message- From: Matt Robinson [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 08, 2004 8:02 AM To: [EMAIL PROTECTED] Subject: Threads issues in Tomcat 5.0.28 Hi, We have 5 instances of Tomcat 5.0.28 running on their own high performance servers (dual XEON / 2GB RAM, etc) receiving AJP13 connector requests via our main web server which has IIS 5, IIS redirector, and Tomcat4. This works great even under high loads except for one thing: after several hours of usage (could be 3 hours or up 24 hours), the number of Tomcat threads on the 5.0.28 systems will suddenly increase at a rapid rate until Tomcat no longer responds to requests. It will hit the max # threads (which defaults to 200) and essentially freeze until it is restarted. This is strange because this behavior does not seem to correspond to increased usage of the particular server it occurs on. We are not sure what is triggering this and what those Tomcat threads are waiting on [they remain busy, waiting and unable to be reused by Tomcat]. My questions are: 1. Has anyone else experienced this kind of Thread explosion problem? 2. Is there a way to find out exactly what each Tomcat Thread is doing/waiting for? 3. Is there a way to periodically clear Tomcat's threadpool -- i.e. get rid of waiting/busy/unusued threads. We are working on ways to automatically restart Tomcat once a certain # of threads is reached, but this is not an acceptable solution, only a temporary workaround of course. Many thanks in advance __ Do you Yahoo!? Take Yahoo! Mail with you! Get it on your mobile phone. http://mobile.yahoo.com/maildemo - 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] 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] __ Do you Yahoo!? All your favorites on one personal page - Try My Yahoo! http://my.yahoo.com - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED
RE: Threads issues in Tomcat 5.0.28
Hi, Here is an example you can follow: Connector className=org.apache.coyote.tomcat5.CoyoteConnector port=9000 protocol=AJP/1.3 address=111.222.333.444 numThreads=20 maxThreads=100 minSpareThreads=25 maxSpareThreads=50 debug=0 connectionTimeout=12 / Hope this helps. Arnab -Original Message- From: Arnab Chakravarty [mailto:[EMAIL PROTECTED] Sent: Thursday, December 09, 2004 9:44 AM To: Tomcat Users List Subject: RE: Threads issues in Tomcat 5.0.28 Hey, The connector tag in the server.xml where you mention the port for ajp13 is the place where you should specify the thread configuration. You can find more information here: http://jakarta.apache.org/tomcat/tomcat-5.0-doc/config/ajp.html Hope it helps. Arnab -Original Message- From: Matt Robinson [mailto:[EMAIL PROTECTED] Sent: Thursday, December 09, 2004 2:29 AM To: Tomcat Users List Subject: RE: Threads issues in Tomcat 5.0.28 Hi Yoav, Thanks for the response I will be sure to include my Thread dump. Meanwhile it sames that AJP13 in Tomcat5 has no parameters such as maxSpareThreads, maxThreads, etc. We are using AJP13 to handle all requests... The documentation (and all searches I have done) do not mention the ability to use these parameters with AJP13, but they can be used with the HTTP protocol. Anybody have any idea whether AJP13 supports these attributes in Tomcat 5.0? Thanks again, Matt --- Shapira, Yoav [EMAIL PROTECTED] wrote: Hi, Once you get the thread dump, post it, and we can try to help you figure out what's wrong. The Tomcat thread pools should automatically recover unused threads, subject to your configuration (see the maxSpareThreads and releated Connector configuration attributes). Yoav Shapira http://www.yoavshapira.com -Original Message- From: Arnab Chakravarty [mailto:[EMAIL PROTECTED] Sent: Tuesday, December 07, 2004 10:50 PM To: Tomcat Users List Subject: RE: Threads issues in Tomcat 5.0.28 Hey, I see your problem similar to mine some time in the past. What you need to is the following: - Lower the number of threads and keep it close to 120-150 threads. - Are you using a database, if yes, check if the DB connection pool is the bottleneck - Yes, you can find what the 200 threads are doing by taking a threaddump. The way to do this is to use the command - kill -QUIT tomcat pid. Hope this helps. Arnab -Original Message- From: Matt Robinson [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 08, 2004 8:02 AM To: [EMAIL PROTECTED] Subject: Threads issues in Tomcat 5.0.28 Hi, We have 5 instances of Tomcat 5.0.28 running on their own high performance servers (dual XEON / 2GB RAM, etc) receiving AJP13 connector requests via our main web server which has IIS 5, IIS redirector, and Tomcat4. This works great even under high loads except for one thing: after several hours of usage (could be 3 hours or up 24 hours), the number of Tomcat threads on the 5.0.28 systems will suddenly increase at a rapid rate until Tomcat no longer responds to requests. It will hit the max # threads (which defaults to 200) and essentially freeze until it is restarted. This is strange because this behavior does not seem to correspond to increased usage of the particular server it occurs on. We are not sure what is triggering this and what those Tomcat threads are waiting on [they remain busy, waiting and unable to be reused by Tomcat]. My questions are: 1. Has anyone else experienced this kind of Thread explosion problem? 2. Is there a way to find out exactly what each Tomcat Thread is doing/waiting for? 3. Is there a way to periodically clear Tomcat's threadpool -- i.e. get rid of waiting/busy/unusued threads. We are working on ways to automatically restart Tomcat once a certain # of threads is reached, but this is not an acceptable solution, only a temporary workaround of course. Many thanks in advance __ Do you Yahoo!? Take Yahoo! Mail with you! Get it on your mobile phone. http://mobile.yahoo.com/maildemo - 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] 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
RE: Threads issues in Tomcat 5.0.28
Hey, I see your problem similar to mine some time in the past. What you need to is the following: - Lower the number of threads and keep it close to 120-150 threads. - Are you using a database, if yes, check if the DB connection pool is the bottleneck - Yes, you can find what the 200 threads are doing by taking a threaddump. The way to do this is to use the command - kill -QUIT tomcat pid. Hope this helps. Arnab -Original Message- From: Matt Robinson [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 08, 2004 8:02 AM To: [EMAIL PROTECTED] Subject: Threads issues in Tomcat 5.0.28 Hi, We have 5 instances of Tomcat 5.0.28 running on their own high performance servers (dual XEON / 2GB RAM, etc) receiving AJP13 connector requests via our main web server which has IIS 5, IIS redirector, and Tomcat4. This works great even under high loads except for one thing: after several hours of usage (could be 3 hours or up 24 hours), the number of Tomcat threads on the 5.0.28 systems will suddenly increase at a rapid rate until Tomcat no longer responds to requests. It will hit the max # threads (which defaults to 200) and essentially freeze until it is restarted. This is strange because this behavior does not seem to correspond to increased usage of the particular server it occurs on. We are not sure what is triggering this and what those Tomcat threads are waiting on [they remain busy, waiting and unable to be reused by Tomcat]. My questions are: 1. Has anyone else experienced this kind of Thread explosion problem? 2. Is there a way to find out exactly what each Tomcat Thread is doing/waiting for? 3. Is there a way to periodically clear Tomcat's threadpool -- i.e. get rid of waiting/busy/unusued threads. We are working on ways to automatically restart Tomcat once a certain # of threads is reached, but this is not an acceptable solution, only a temporary workaround of course. Many thanks in advance __ Do you Yahoo!? Take Yahoo! Mail with you! Get it on your mobile phone. http://mobile.yahoo.com/maildemo - 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]
