RE: MaxPermSize, Tomcat startup trouble
Caldarale, Charles R wrote: It's also irrelevant. The heap size (-Xmx + -XX:MaxPermSize) must fit in a contiguous area of virtual memory within the process. On a 32-bit Windows system, the process space is 2 GB, unfortunately very fragmented by DLLs that Windows insists on scattering throughout the area. You will never be able to get a total heap larger than 1.2 - 1.5 GB. (There is a boot-time switch in Windows Server to allow 3 GB user process space, but that can cause other problems for the OS.) The above is not possible to achieve on a 32-bit system - ever. Shrink the MaxPermSize down to something reasonable (e.g., 128m), then experiment with -Xmx until the JVM loads. Normally best to set -Xms and -Xmx to the same value. - Chuck Thank you both for replying. The architecture is indeed x86 (Windows 2003 server) and changing OS is not an option right now (going live soon). The strange thing is that if we place all 20 contexts in the Tomcat 6.0\webapps then we get this exception/error: ..backtrace.. Cause by java.lang.OutOfMemoryError: PermGen space. If we place the contexts outside of the Tomcat 6.0\webapps (updated server.xml ofc), then we DON'T get the OutOfMemoryError. Because we'd like to use the WAR update mechanism, keeping all webapps in Tomcat 6.0\webapps is preferred. -- View this message in context: http://www.nabble.com/MaxPermSize%2C-Tomcat-startup-trouble-tp23744089p23756562.html Sent from the Tomcat - User mailing list archive at Nabble.com. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: MaxPermSize, Tomcat startup trouble
From: Henjo [mailto:henj...@gmail.com] Thank you both for replying. The architecture is indeed x86 (Windows 2003 server) and changing OS is not an option right now (going live soon). The alternative view: You can go live with a known-unreliable system, or you can change OS and go live with a maybe-unreliable system :-). The strange thing is that if we place all 20 contexts in the Tomcat 6.0\webapps then we get this exception/error: ..backtrace.. Cause by java.lang.OutOfMemoryError: PermGen space. If we place the contexts outside of the Tomcat 6.0\webapps (updated server.xml ofc), then we DON'T get the OutOfMemoryError. Because we'd like to use the WAR update mechanism, keeping all webapps in Tomcat 6.0\webapps is preferred. I'm somewhat surprised. Do all 20 contexts get started when they're elsewhere? By the way, there's one other thing you *could* try if you had to reduce memory usage. I don't like it, because it makes versioning the webapps a nightmare; but it might save you quite a lot of RAM and allow you to go live on the current hardware. The choice is yours! If many of your webapps use the same versions of the same jars, you *could* share them between webapps. The classes will then be loaded once, rather than once per webapp, reducing the amount of PermGen required. The problem, of course, is that your webapps are then locked to the same library versions - updating one webapp with a new library is a problem. If you want to look at this approach, check the Tomcat 6 classloader how-to on the web site. But if you do this, I would suggest you regard it as an emergency hack and look urgently at ways to remove it. - Peter - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: MaxPermSize, Tomcat startup trouble
Peter's option is a valid one. I use this approach myself to limit the size of PermGen. Of course, I may have more control over the apps than you do. If you do need to load different version, you should be able to put the alternate version in the apps WEB-INF/lib directory and the app's loader will prefer it. (at least at 5.5). One thing to watch out for. Some libraries do not play nice. For instance, log4j gets instantiated once for the jvm. If you share the lg4j library but each app has its own log file definition, they will end up meshing into one log (I think the last one instantiated). Jeff -Original Message- From: Peter Crowther [mailto:peter.crowt...@melandra.com] Sent: Thursday, May 28, 2009 4:03 AM To: 'Tomcat Users List' Subject: RE: MaxPermSize, Tomcat startup trouble By the way, there's one other thing you *could* try if you had to reduce memory usage. I don't like it, because it makes versioning the webapps a nightmare; but it might save you quite a lot of RAM and allow you to go live on the current hardware. The choice is yours! If many of your webapps use the same versions of the same jars, you *could* share them between webapps. The classes will then be loaded once, rather than once per webapp, reducing the amount of PermGen required. The problem, of course, is that your webapps are then locked to the same library versions - updating one webapp with a new library is a problem. If you want to look at this approach, check the Tomcat 6 classloader how-to on the web site. But if you do this, I would suggest you regard it as an emergency hack and look urgently at ways to remove it. - Peter *** NOTICE * This message is intended for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by reply or by telephone (call us collect at 512-343-9100) and immediately delete this message and all its attachments. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: MaxPermSize, Tomcat startup trouble
Any ideas how we can get a much larger PermSpace going? I believe there are some java options that control how the memory is divided between the different generations. I seem to remember a ratio option that you could look into. I had to do this for one implementation. Check the java documentation for your JVM. Also, the maximum memory size you can supply to -Xmx is 1536M, and that is only if you use the /3G boot option for Windows. Otherwise, it is about 1200M. Not much can be done about this. It's an MS thing. *** NOTICE * This message is intended for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by reply or by telephone (call us collect at 512-343-9100) and immediately delete this message and all its attachments. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: MaxPermSize, Tomcat startup trouble
From: Jeffrey Janner [mailto:jeffrey.jan...@polydyne.com] Subject: RE: MaxPermSize, Tomcat startup trouble I believe there are some java options that control how the memory is divided between the different generations. Not for PermGen - its size is controlled explicitly. It's not really a generation in proper GC terminology - nothing ever migrates into it. I seem to remember a ratio option that you could look into. That's only for young vs old generations. Also, the maximum memory size you can supply to -Xmx is 1536M That's platform and architecture dependant; there's no single value that will work everywhere. The next service pack will change it. - 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: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: MaxPermSize, Tomcat startup trouble
I know I increased the PermGen size. I'll see if I can find it -- later. The max -Xmx was specifically meant for Windows 32-bit. Sorry that I wasn't clear. -Original Message- From: Caldarale, Charles R [mailto:chuck.caldar...@unisys.com] Sent: Thursday, May 28, 2009 9:09 AM To: Tomcat Users List Subject: RE: MaxPermSize, Tomcat startup trouble From: Jeffrey Janner [mailto:jeffrey.jan...@polydyne.com] Subject: RE: MaxPermSize, Tomcat startup trouble I believe there are some java options that control how the memory is divided between the different generations. Not for PermGen - its size is controlled explicitly. It's not really a generation in proper GC terminology - nothing ever migrates into it. I seem to remember a ratio option that you could look into. That's only for young vs old generations. Also, the maximum memory size you can supply to -Xmx is 1536M That's platform and architecture dependant; there's no single value that will work everywhere. The next service pack will change it. - 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: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org *** NOTICE * This message is intended for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by reply or by telephone (call us collect at 512-343-9100) and immediately delete this message and all its attachments. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: MaxPermSize, Tomcat startup trouble
-XX:MaxPermSize=128m Since it's an XX option, you need to verify that it is available with your version of Java. Jeff -Original Message- From: Jeffrey Janner [mailto:jeffrey.jan...@polydyne.com] Sent: Thursday, May 28, 2009 10:58 AM To: Tomcat Users List Subject: RE: MaxPermSize, Tomcat startup trouble I know I increased the PermGen size. I'll see if I can find it -- later. The max -Xmx was specifically meant for Windows 32-bit. Sorry that I wasn't clear. -Original Message- From: Caldarale, Charles R [mailto:chuck.caldar...@unisys.com] Sent: Thursday, May 28, 2009 9:09 AM To: Tomcat Users List Subject: RE: MaxPermSize, Tomcat startup trouble From: Jeffrey Janner [mailto:jeffrey.jan...@polydyne.com] Subject: RE: MaxPermSize, Tomcat startup trouble I believe there are some java options that control how the memory is divided between the different generations. Not for PermGen - its size is controlled explicitly. It's not really a generation in proper GC terminology - nothing ever migrates into it. I seem to remember a ratio option that you could look into. That's only for young vs old generations. Also, the maximum memory size you can supply to -Xmx is 1536M That's platform and architecture dependant; there's no single value that will work everywhere. The next service pack will change it. - 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: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org *** NOTICE * This message is intended for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by reply or by telephone (call us collect at 512-343-9100) and immediately delete this message and all its attachments. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org *** NOTICE * This message is intended for the use of the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by reply or by telephone (call us collect at 512-343-9100) and immediately delete this message and all its attachments. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: MaxPermSize, Tomcat startup trouble
From: Henjo [mailto:henj...@gmail.com] Subject: MaxPermSize, Tomcat startup trouble AFAIK the PermSpace holds all compiled java classes (and jsps) in RAM. No; it holds the java.lang.Class instances that represent the loaded classes (including JSPs). Size of a class file on disk has *nothing* to do with the size of a java.lang.Class object. The number of webapps and JSPs you have is not particularly large. Available RAM is 3.5Gb on the machine, so that's not a problem. It's also irrelevant. The heap size (-Xmx + -XX:MaxPermSize) must fit in a contiguous area of virtual memory within the process. On a 32-bit Windows system, the process space is 2 GB, unfortunately very fragmented by DLLs that Windows insists on scattering throughout the area. You will never be able to get a total heap larger than 1.2 - 1.5 GB. (There is a boot-time switch in Windows Server to allow 3 GB user process space, but that can cause other problems for the OS.) -Xmx1536m -XX:MaxPermSize=1024m The above is not possible to achieve on a 32-bit system - ever. Shrink the MaxPermSize down to something reasonable (e.g., 128m), then experiment with -Xmx until the JVM loads. Normally best to set -Xms and -Xmx to the same value. -XX:+CMSPermGenSweepingEnabled Irrelevant unless you have enabled the concurrent mark-sweep GC mechanism. - 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: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: MaxPermSize, Tomcat startup trouble
From: Henjo [henj...@gmail.com] OS is Windows 2003. x86 or x64? Available RAM is 3.5Gb on the machine, so that's not a problem. I assume x86 from that sizing. As Chuck points out, you won't get the space you want given Windows' appalling memory use. Any ideas how we can get a much larger PermSpace going? Change to an x64 Windows architecture, or change to a non-Windows OS (may not be large enough, even so), or run two (or more) Tomcat instances on the machine and split the contexts between them so that you don't need 1G of Permspace. - Peter - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
