Re: tomcat6 -minheap,maxheap size
On 3/23/2016 9:19 AM, Christopher Schultz wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 David, On 3/23/16 8:02 AM, David kerber wrote: On 3/23/2016 3:36 AM, Mahudeswaran A wrote: Hello All, Is there any recommended maximum setting for tomcat-6 32bit version running on windows 64bit OS No, there is not. It all depends on your app's requirements. I have applications for which 64MB is plenty, and others which need 1024MB. I think the max on 32-bit is 2048MB (2GB), but I'm not sure of that. Something like that, depending upon a few things. I think I wasn't able to get above 1520MiB on 32-bit Windows, but that's because of some weirdness the OS does with kernel-versus-process address space. Evidently, the process can have 32-bit pointers, but reserves *half* of that for kernel space. You used to be able to use some kind of boot parameter to set that kernel/process split to 3GiB/1GiB... not sure if that works anymore. It doesn't matter, though... everyone should be on 64-bit, now. If you are running on a 64-bit OS, it *generally* makes sense to use a 64-bit JVM, but I can see lots of reasons to use a 32-bit JVM - if you can get away with it - mostly memory-related. We run 32-bit to simplify installations. We have several non-java applications that are still 32-bit, and running 32-bit java lets us get away with installing only one set of db drivers and ODBC DSNs, which all applications (both java and non-java) can use. None of them need 64-bit java just for memory requirements. 64-bit JVMs can use compressed object pointers (and they do by default) to take up less memory than if they used native pointers, but the reality is that a 64-bit JVM simply requires more memory than the same exact application running under a 32-bit JVM. If you can get away with less than ~2GiB of heap, then I would say stick with the 32-bit JVM. You can always move to 64-bit. Note that Tomcat itself is 100% Java and so there isn't really a "32-bit Tomcat" though it is packaged that way: the 32-bit package just has a 32-bit installer and is bundled with the 32-bit Windows service, a 32-bit tcnative, etc. We would like to change the default setting and looking for max size/count for 32bit tomcat-6 running on 64bit windows OS. Min heap size=? Max heap size=? Max Thread count=? IMO, you should only use as much memory as you actually need. Some people like allocating enormous heaps because "more is better", but I tend to think that if you have a huge heap, it will take you forever to notice any kinds of memory problems that you have. - -chris (Still very happily running in production with 512MiB heaps for our "biggest" web applications.) -BEGIN PGP SIGNATURE- Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlbyl8QACgkQ9CaO5/Lv0PA6cQCeKkbE2m3MCRfKQyMs3oBRJnYY misAn0h4wlUWCNx3byztozAZJGmStaZV =1VG8 -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: tomcat6 -minheap,maxheap size
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 David, On 3/23/16 8:02 AM, David kerber wrote: > On 3/23/2016 3:36 AM, Mahudeswaran A wrote: >> Hello All, Is there any recommended maximum setting for tomcat-6 >> 32bit version running on windows 64bit OS > > No, there is not. It all depends on your app's requirements. I > have applications for which 64MB is plenty, and others which need > 1024MB. I think the max on 32-bit is 2048MB (2GB), but I'm not > sure of that. Something like that, depending upon a few things. I think I wasn't able to get above 1520MiB on 32-bit Windows, but that's because of some weirdness the OS does with kernel-versus-process address space. Evidently, the process can have 32-bit pointers, but reserves *half* of that for kernel space. You used to be able to use some kind of boot parameter to set that kernel/process split to 3GiB/1GiB... not sure if that works anymore. It doesn't matter, though... everyone should be on 64-bit, now. If you are running on a 64-bit OS, it *generally* makes sense to use a 64-bit JVM, but I can see lots of reasons to use a 32-bit JVM - if you can get away with it - mostly memory-related. 64-bit JVMs can use compressed object pointers (and they do by default) to take up less memory than if they used native pointers, but the reality is that a 64-bit JVM simply requires more memory than the same exact application running under a 32-bit JVM. If you can get away with less than ~2GiB of heap, then I would say stick with the 32-bit JVM. You can always move to 64-bit. Note that Tomcat itself is 100% Java and so there isn't really a "32-bit Tomcat" though it is packaged that way: the 32-bit package just has a 32-bit installer and is bundled with the 32-bit Windows service, a 32-bit tcnative, etc. >> We would like to change the default setting and looking for max >> size/count for 32bit tomcat-6 running on 64bit windows OS. Min >> heap size=? Max heap size=? Max Thread count=? IMO, you should only use as much memory as you actually need. Some people like allocating enormous heaps because "more is better", but I tend to think that if you have a huge heap, it will take you forever to notice any kinds of memory problems that you have. - -chris (Still very happily running in production with 512MiB heaps for our "biggest" web applications.) -BEGIN PGP SIGNATURE- Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlbyl8QACgkQ9CaO5/Lv0PA6cQCeKkbE2m3MCRfKQyMs3oBRJnYY misAn0h4wlUWCNx3byztozAZJGmStaZV =1VG8 -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: tomcat6 -minheap,maxheap size
On 3/23/2016 3:36 AM, Mahudeswaran A wrote: Hello All, Is there any recommended maximum setting for tomcat-6 32bit version running on windows 64bit OS No, there is not. It all depends on your app's requirements. I have applications for which 64MB is plenty, and others which need 1024MB. I think the max on 32-bit is 2048MB (2GB), but I'm not sure of that. We would like to change the default setting and looking for max size/count for 32bit tomcat-6 running on 64bit windows OS. Min heap size=? Max heap size=? Max Thread count=? Thanks and regards - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
tomcat6 -minheap,maxheap size
Hello All, Is there any recommended maximum setting for tomcat-6 32bit version running on windows 64bit OS We would like to change the default setting and looking for max size/count for 32bit tomcat-6 running on 64bit windows OS. Min heap size=? Max heap size=? Max Thread count=? Thanks and regards
