RE: Tomcat hangs up from time to time
I just finished dealing with the same problem. In the end I ended up having to install a new version of linux (rh 9 - rh enterprise) to resolve it. I'm not sure about the exact cause, but given that the problem acts like a socket problem (Hard to tell without errors) I'm guessing that that would be a good place to start looking. Please let me know if you find anything. Larry -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Sunday, March 20, 2005 11:55 PM To: Tomcat Users List Subject: Re: Tomcat hangs up from time to time Well, I have tried to kill tomcat process with SIGQUIT in order to take thread dump. No any reaction. Only SIGKILL works. On Thu, 17 Mar 2005 11:28:58 - Peter Crowther [EMAIL PROTECTED] wrote: From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] But about two-five times per day, Tomcat hangs up, java (version is 1.5.0_01-b08) eats much cpu (up to 90%), and no any response from Tomcat, no warnings/errors in logs. I even can't stop it with shutdown.sh! Have anyone the same problem? Any solutions, advices, thoughts? Check your JVM documentation, and then kill the main Tomcat process with the signal that causes a thread dump. Read/grep through the thread dump - who's doing what? - Peter - 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] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Tomcat hangs up from time to time
Well, I have tried to kill tomcat process with SIGQUIT in order to take thread dump. No any reaction. Only SIGKILL works. On Thu, 17 Mar 2005 11:28:58 - Peter Crowther [EMAIL PROTECTED] wrote: From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] But about two-five times per day, Tomcat hangs up, java (version is 1.5.0_01-b08) eats much cpu (up to 90%), and no any response from Tomcat, no warnings/errors in logs. I even can't stop it with shutdown.sh! Have anyone the same problem? Any solutions, advices, thoughts? Check your JVM documentation, and then kill the main Tomcat process with the signal that causes a thread dump. Read/grep through the thread dump - who's doing what? - Peter - 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]
Tomcat hangs up from time to time
Hi all, Lately, I have set up Tomcat 5.5.7 on Slackware Linux 9.1. I have configured four virtual hosts for me and my workmates. We develop a few web apps with Struts, Torque, Velocity, etc. Application base directories, scratch directories and tomcat logs are located on NFS share. Common approach is edit source, compile, reload web app with org.apache.catalina.ant.ReloadTask, look at browser time and again. But about two-five times per day, Tomcat hangs up, java (version is 1.5.0_01-b08) eats much cpu (up to 90%), and no any response from Tomcat, no warnings/errors in logs. I even can't stop it with shutdown.sh! Have anyone the same problem? Any solutions, advices, thoughts? Thanks. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat hangs up from time to time
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] But about two-five times per day, Tomcat hangs up, java (version is 1.5.0_01-b08) eats much cpu (up to 90%), and no any response from Tomcat, no warnings/errors in logs. I even can't stop it with shutdown.sh! Have anyone the same problem? Any solutions, advices, thoughts? Check your JVM documentation, and then kill the main Tomcat process with the signal that causes a thread dump. Read/grep through the thread dump - who's doing what? - Peter - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Tomcat hangs up ... Huge count of webapps
Hi everybody and java experts, i have a huge count of webapps (approximately 25) in my Tomcat here, running on Suse Linux 9.1. After a few connection requests, Tomcat just hangs up and doesn't accept anymore connections. I can't kill the process anyway, only killall -9 java helps. Well, beneath the fact that my server has 2 gigabytes of ram, only 40MB are available after starting tomcat. So, tomcat allocates 1.96 gigabytes of ram. Question is: what is the maximum count of webapps, Tomcat is able to handle? Or are there any other configuration hints? System is - Suse Linux 9.1 - 2GB of RAM - 3.0 Ghz Machine - JDK1.4.2_06 and JRE1.4.2_05 (same effect on every Java version) - Tomcat 4.1.31 or Tomcat bundle with TDK-2.2 (TurbineDevelopmentKit) .. This is an absolut urgent issue! Please reply asap .. Thx a lot Regard, Martin Eberle
RE: Tomcat hangs up ... Huge count of webapps
Hi, i have a huge count of webapps (approximately 25) in my Tomcat here, I wouldn't classify 25 as huge, but I suppose that's subjective. We have servers running that many webapps, but they're small webapps. Well, beneath the fact that my server has 2 gigabytes of ram, only 40MB are available after starting tomcat. So, tomcat allocates 1.96 gigabytes of ram. You control the JVM; if it allocates 1.96GB it means you gave it -Xmx2G *at least*. Even if that's the case on purpose, you need to redesign your deployment practice because leaving 40MB free on a 2GB server will only lead to bad things. Question is: what is the maximum count of webapps, Tomcat is able to handle? It's limited by your environment and requirements. Tomcat imposes no limit of its own. I ran a load test a year or so ago with 100 webapps deployed, and it worked (with good response times and CPU usage), but the apps were small and the machine was massive. Or are there any other configuration hints? Only the usual: think and apply performance testing principles. There's no magic switch or configuration. In your case, you probably want to split the apps into multiple Tomcat servers, and profile each app (or small set of apps) separately to determine its hardware and memory requirements. Then figured out how you want to use your hardware and configure as many instances of Tomcat as you need. - JDK1.4.2_06 and JRE1.4.2_05 (same effect on every Java version) Those two versions are not that different ;) It might be worth your time to try J2SE 5.0, JRockit, or other JVMs. This is an absolut urgent issue! Please reply asap .. Thx a lot Then you're SOL for now ;) It's no fun doing capacity planning after deployment, and there are no easy shortcuts ;( Yoav Shapira http://www.yoavshapira.com 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]
AW: Tomcat hangs up ... Huge count of webapps
i have a huge count of webapps (approximately 25) in my Tomcat here, I wouldn't classify 25 as huge, but I suppose that's subjective. We have servers running that many webapps, but they're small webapps. ### Ok. It's not THAT huge .. but we have ~45 users per webapp which are going to connect on nearly the same time .. Well, beneath the fact that my server has 2 gigabytes of ram, only 40MB are available after starting tomcat. So, tomcat allocates 1.96 gigabytes of ram. You control the JVM; if it allocates 1.96GB it means you gave it -Xmx2G *at least*. Even if that's the case on purpose, you need to redesign your deployment practice because leaving 40MB free on a 2GB server will only lead to bad things. I'm bringing up the JVM with /usr/j2re142_05/bin/java -server -Xmx1024m -Xms256m -D ... Question is: what is the maximum count of webapps, Tomcat is able to handle? It's limited by your environment and requirements. Tomcat imposes no limit of its own. I ran a load test a year or so ago with 100 webapps deployed, and it worked (with good response times and CPU usage), but the apps were small and the machine was massive. Then you're SOL for now ;) It's no fun doing capacity planning after deployment, and there are no easy shortcuts ;( What's SOL? We didn't expect to get THAT massive problems with tomcat as i know that tomcat run even better some time ago :( - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat hangs up ... Huge count of webapps
Hi, ### Ok. It's not THAT huge .. but we have ~45 users per webapp which are going to connect on nearly the same time .. 25 apps * 45 users = virtually 1125 concurrent users, that's significant. I'm bringing up the JVM with /usr/j2re142_05/bin/java -server -Xmx1024m -Xms256m -D ... Then it's not allocating 1.96GB: how did you get that number for your original post? What's SOL? We didn't expect to get THAT massive problems with tomcat as i know that tomcat run even better some time ago :( SOL: www.acronymfinder.com/default.asp?p=dictString=exactAcronym=SOL. Tomcat has only improved in terms of memory usage, stability, and performance over time. It's more likely that your apps, your load, your hardware, or a combination of the above have changed. Regardless, this is why you should also stress-test your applications as they would be deployed in production against the expected user load. For now, you should probably split the apps into multiple Tomcat instances running on separate servers. That way would reduce the load, reduce the JVM size, and increase the performance seen by your users. Yoav Shapira http://www.yoavshapira.com 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: Tomcat Hangs-UP...
Okay, a simple answer from a simple mind: Check that you are closing resources in your java code appropriately. Don't rely on garbage collection! Are you closing any files opened by your Java code? Are you always closing your jdbc SQL statements/result sets, etc...? Are you closing your Oracle connections? Are there too many open connections? Are there any blocking db locks? I have had this problem before where my db connected application had not committed it's transaction and ended up hanging tomcat. Always check to see that your resources are being released and not halting other requests. Since you're using Oracle, check the V$SESSION view to make sure you don't have more active connections than you believe you should have. Check the v$session_wait to make sure nothing is blocked. I'll bet a t-shirt that it's a db problem. If you can't get to those views, ask your friendly dba to help. [EMAIL PROTECTED] 05/28/02 07:24PM Here, we have the same problem!!! What can it be? Our configuration: - SunOS 5.8; - Solaris 8; - Dual UltraSparc 400Mhz; - J2SE SUN 1.4; - Tomcat 4.0.3; - We are using -Xmx1024 -Xms512; - MaxProcessors=250, MinProcessors=10, acceptCount=250; - Oracle Thin JDBC; PS 1: we are not having the classic OutOfMemory error. Tomcat just hangs-up with no reason. PS 2: We already used OptimizeIt to tune the application. PS 3: Tomcat stops even with a low rate of usage. Wagner Danda -- Mensagem original --- De : Rui Oliveira [EMAIL PROTECTED] Para: [EMAIL PROTECTED] Cc : Data: Tue, 28 May 2002 18:54:36 +0100 Assunto : Tomcat Hangs-UP... Hello, I have a Tomcat Server running on Solaris as JSP and WEB server. Aft er executing for a while, the Tomcat just Hangs-UP and the only way of restarting it is to kill the Tomcat process. My configuration is the following: - SunOS 5.8 - Solaris 8 - JRE 1.3.1_03 - Tomcat 4.0.3 Does anyone have a clue on what is the problem? Regards Rui Oliveira -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: Tomcat Hangs-UP...
Hello, Hi, my comments are below. - Okay, a simple answer from a simple mind: Check that you are closing resources in your java code appropriately. Don't rely on garbage collection! Are you closing any files opened by your Java code? Yes, I am. Are you always closing your jdbc SQL statements/result sets, etc...? Yes, I am. If I don´t close-it, I will get TooMayOpenCursors errors. I´ve already fixed this problem. Are you closing your Oracle connections? Are there too many open connections? I am using an Oracle implementation of connection pool. Every user that log on system get an connection from that pool. The connection will not br released until this user close the browser window, or the tomcat session gets timeout (30 minutes). Tomcat is hanging with 130 (more or less) connections out of the pool (about 110 users). Are there any blocking db locks? No, there are not. I have had this problem before where my db connected application had not committed it's transaction and ended up hanging tomcat. Always check to see that your resources are being released and not halting other requests. Our methods that use/need transaction (doing updates or deletes) always do commit or rollback, BUT, for connections that only do select querys, commit or rollback are never called. MAY THIS BE A PROBLEM Remember that an connection is associated with the user (browser) session... Since you're using Oracle, check the V$SESSION view to make sure you don't have more active connections than you believe you should have. Check the v$session_wait to make sure nothing is blocked. I'll bet a t-shirt that it's a db problem. If you can't get to those views, ask your friendly dba to help. I am already doing this for a long time, and we are not having this problem. Well, just to inform about our situation: our application is already in production, and there is about 300 users TRYING to use-it... Another thing, our company depends 100% of this software. More about our structure: we are using an arrowpoint cluster with 2 Sun UltraSparc (see descriptions below). And fortunetly, wen tomcat hangs in one machine, the users can go the another tomcat. BUT, at every tomcat stop, all users of that machine have to re-login into the another tomcat (because the user loose his session). Any other help? Any idea?? Please, we are almost givin up of tomcat and changing to another payed solution (like Websphere, JRun, ...) PS: we are trying to solve this problem since 4 months ago!!! We arealdy tried A LOT of alternatives solutions... We neen and serius help. thank you all in advance, Wagner Danda [EMAIL PROTECTED] Sun Java Certified Programmer for the Java 2 [tm] [EMAIL PROTECTED] 05/28/02 07:24PM Here, we have the same problem!!! What can it be? Our configuration: - SunOS 5.8; - Solaris 8; - Dual UltraSparc 400Mhz; - J2SE SUN 1.4; - Tomcat 4.0.3; - We are using -Xmx1024 -Xms512; - MaxProcessors=250, MinProcessors=10, acceptCount=250; - Oracle Thin JDBC; PS 1: we are not having the classic OutOfMemory error. Tomcat just hangs-up with no reason. PS 2: We already used OptimizeIt to tune the application. PS 3: Tomcat stops even with a low rate of usage. Wagner Danda -- Mensagem original --- De : Rui Oliveira [EMAIL PROTECTED] Para: [EMAIL PROTECTED] Cc : Data: Tue, 28 May 2002 18:54:36 +0100 Assunto : Tomcat Hangs-UP... Hello, I have a Tomcat Server running on Solaris as JSP and WEB server. Aft er executing for a while, the Tomcat just Hangs-UP and the only way of restarting it is to kill the Tomcat process. My configuration is the following: - SunOS 5.8 - Solaris 8 - JRE 1.3.1_03 - Tomcat 4.0.3 Does anyone have a clue on what is the problem? Regards Rui Oliveira -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Re: Tomcat Hangs-UP...
Two comments below. fillup Are you closing your Oracle connections? Are there too many open connections? I am using an Oracle implementation of connection pool. Every user that log on system get an connection from that pool. The connection will not br released until this user close the browser window, or the tomcat session gets timeout (30 minutes). Tomcat is hanging with 130 (more or less) connections out of the pool (about 110 users). This is the wrong way to use a connection pool, unless you have a very narrow set of specific theoretical requirements, which I still have never seen in practice. Each REQUEST should be grabbing a connection and returning it to the pool, not each SESSION. Using it for sessions in fact makes your pool worse and slower than just opening a new connection for each request with zero pooling. You're using the pool in the wrong way. I have had this problem before where my db connected application had not committed it's transaction and ended up hanging tomcat. Always check to see that your resources are being released and not halting other requests. Our methods that use/need transaction (doing updates or deletes) always do commit or rollback, BUT, for connections that only do select querys, commit or rollback are never called. MAY THIS BE A PROBLEM Remember that an connection is associated with the user (browser) session... see Connection.setAutoCommit( ) Since you're using Oracle, check the V$SESSION view to make sure you don't have more active connections than you believe you should have. Check the v$session_wait to make sure nothing is blocked. I'll bet a t-shirt that it's a db problem. If you can't get to those views, ask your friendly dba to help. I am already doing this for a long time, and we are not having this problem. Well, just to inform about our situation: our application is already in production, and there is about 300 users TRYING to use-it... Another thing, our company depends 100% of this software. More about our structure: we are using an arrowpoint cluster with 2 Sun UltraSparc (see descriptions below). And fortunetly, wen tomcat hangs in one machine, the users can go the another tomcat. BUT, at every tomcat stop, all users of that machine have to re-login into the another tomcat (because the user loose his session). Any other help? Any idea?? Please, we are almost givin up of tomcat and changing to another payed solution (like Websphere, JRun, ...) PS: we are trying to solve this problem since 4 months ago!!! We arealdy tried A LOT of alternatives solutions... We neen and serius help. thank you all in advance, Wagner Danda [EMAIL PROTECTED] Sun Java Certified Programmer for the Java 2 [tm] [EMAIL PROTECTED] 05/28/02 07:24PM Here, we have the same problem!!! What can it be? Our configuration: - SunOS 5.8; - Solaris 8; - Dual UltraSparc 400Mhz; - J2SE SUN 1.4; - Tomcat 4.0.3; - We are using -Xmx1024 -Xms512; - MaxProcessors=250, MinProcessors=10, acceptCount=250; - Oracle Thin JDBC; PS 1: we are not having the classic OutOfMemory error. Tomcat just hangs-up with no reason. PS 2: We already used OptimizeIt to tune the application. PS 3: Tomcat stops even with a low rate of usage. Wagner Danda -- Mensagem original --- De : Rui Oliveira [EMAIL PROTECTED] Para: [EMAIL PROTECTED] Cc : Data: Tue, 28 May 2002 18:54:36 +0100 Assunto : Tomcat Hangs-UP... Hello, I have a Tomcat Server running on Solaris as JSP and WEB server. Aft er executing for a while, the Tomcat just Hangs-UP and the only way of restarting it is to kill the Tomcat process. My configuration is the following: - SunOS 5.8 - Solaris 8 - JRE 1.3.1_03 - Tomcat 4.0.3 Does anyone have a clue on what is the problem? Regards Rui Oliveira -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
Tomcat Hangs-UP...
Hello, I have a Tomcat Server running on Solaris as JSP and WEB server. After executing for a while, the Tomcat just Hangs-UP and the only way of restarting it is to kill the Tomcat process. My configuration is the following: - SunOS 5.8 - Solaris 8 - JRE 1.3.1_03 - Tomcat 4.0.3 Does anyone have a clue on what is the problem? Regards Rui Oliveira
Re: Tomcat Hangs-UP...
Here, we have the same problem!!! What can it be? Our configuration: - SunOS 5.8; - Solaris 8; - Dual UltraSparc 400Mhz; - J2SE SUN 1.4; - Tomcat 4.0.3; - We are using -Xmx1024 -Xms512; - MaxProcessors=250, MinProcessors=10, acceptCount=250; - Oracle Thin JDBC; PS 1: we are not having the classic OutOfMemory error. Tomcat just hangs-up with no reason. PS 2: We already used OptimizeIt to tune the application. PS 3: Tomcat stops even with a low rate of usage. Wagner Danda -- Mensagem original --- De : Rui Oliveira [EMAIL PROTECTED] Para: [EMAIL PROTECTED] Cc : Data: Tue, 28 May 2002 18:54:36 +0100 Assunto : Tomcat Hangs-UP... Hello, I have a Tomcat Server running on Solaris as JSP and WEB server. Aft er executing for a while, the Tomcat just Hangs-UP and the only way of restarting it is to kill the Tomcat process. My configuration is the following: - SunOS 5.8 - Solaris 8 - JRE 1.3.1_03 - Tomcat 4.0.3 Does anyone have a clue on what is the problem? Regards Rui Oliveira -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
