This is asked on the mailing list a bunch but in short, the theoretical max you could use running windows 32 bit is 1800MB, but depending on other programs loaded at startup (virus checkers, firewall software etc.) I have see ranges from 1024MB-1500MB (MAX!). We typically used 1024MB Initial/1024MB max because our app never used above 950ish MB but depending on your application's memory needs you may need to go higher/lower.
There is also a little known performance boost you can set on your server if you are only using a single JVM on a particular machine. If you are using JDK 1.4.2 and above, use the -XX:+AggressiveHeap directive under the "Java Options" section of your Tomcat Manager app instead of sepecifying Initial/Maximum memory pool values. *NOTE* if you are running anything else on this box like a DB server or something else other than tomcat, this option is NOT recommended!!! This option dynamically manages the heap/garbage collection and made a HUGE difference on our production servers. You will notice that it grabs about 900-950MB ram initially according to manager application and this value will fluctuate as your app needs more/less memory. If people are interested in checking out what happens inside their JVM's memory space, you can use a tool called visualgc from sun's site http://java.sun.com/performance/jvmstat/visualgc.html The latest version is for use with JDK 1.5.x, but If you run tomcat on JDK 1.4.x you can still use it! Just install the JDK 1.5.x ONLY and have the visualgc startup script point the java.exe located in the JDK 1.5.x/bin directory. In order to expose the JVM you might need to start Tomcat using the catalina.bat file instead of relying on the service. -rOcK -----Original Message----- From: joon yoo [mailto:[EMAIL PROTECTED] Sent: Friday, December 02, 2005 2:08 PM To: tomcat-user@jakarta.apache.org Subject: memory limit for tomcat? Hi, Currently on our tomcat 5 server (1GB RAM, Win 2000 server SP4), we have the "initial memory pool" and "max memory pool" values set to 768MB in the apache tomcat properties app. The server is going to be upgraded to 2GB's of RAM, exactly what is the limit of the amount of memory that can be allocated to tomcat and still run stably? Thanks for any help, John --------------------------------------------------------------------- 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]
