Kris is right. These parameters ought to be tweaked for servers with decent amounts of memory installed. On another project our company is working on, we had a machine with 8G (a Sun 4-way server). We were able to set up to 3G on JDK1.3.1. To documentation I found indicated using ISM, about 3.8 was achievable We did have problems and switching to 2G max heap worked. So, I'd caution those trying to use anything higher than 2G on 1.3.1. Perhaps 1.4 has fixed this. I know the documentation says the special memory settings (NewRatio, etc...) are used a little differently. Follow this link for more details; http://java.sun.com/docs/hotspot/index.html
David Kris Schneider wrote: >Sun's 1.4 server (not client) JVM can use a 4GB heap on a 64-bit SPARC >box. Otherwise, I think you're pretty much stuck at 2GB. How much >physical memory and swap space is installed? How much is actually >available for allocation to the JVM when Tomcat gets kicked off? I also >tend to adjust some of the other options. Something typical (for 1.3, >some things have changed for 1.4) might be: > >-Xms512m -Xmx512m -XX:MaxPermSize=96m -XX:NewSize=128m >-XX:MaxNewSize=128m -XX:SurvivorRatio=8 > >I certainly don't claim that those numbers are generally optimal, but >changing them from their defaults can provide dramatic results. A >certain commercial app server I've used would just up die until things >were tweaked out a bit - YMMV. This might also be of interest (for Sun >JVMs anyway): > >http://java.sun.com/docs/hotspot/index.html > >"Sexton, George" wrote: > >>I really doubt it. I seem to recall that for Windows 32 bit applications the >>maximum address space of an application is 2GB. I would try reducing the >>second parameter to below 2GB and see what happens. >> >>I'm sure Sun has some boxes that could do this... >> >>-----Original Message----- >>From: Marinko, Jeff [mailto:[EMAIL PROTECTED]] >>Sent: 15 August, 2002 3:28 PM >>To: 'Tomcat Users List' >>Subject: RE: Checking Tomcat's Memory >> >>Ah, there it is! >> >>So I would add additional "JVM Option Number X" with the -server, -Xms, -Xmx >>parameters and change "JVM Option Count" to account for this. >> >>I've managed to change the VM heap size through editing the catalina.bat >>script, however I get the following: >> >>Error occurred during initialization of VM >>Could not reserve enough space for object heap >> >>when I try to set my parameters at -Xms1024m -Xmx3072m (currently running at >>128m and 1024m). Are there any VMs out there that can handle this kind of >>memory (1+ gigs to start)? >> >>Thanks! >> >>-----Original Message----- >>From: Sexton, George [mailto:[EMAIL PROTECTED]] >>Sent: Thursday, August 15, 2002 1:20 PM >>To: Tomcat Users List >>Subject: RE: Checking Tomcat's Memory >> >>HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<ServiceName>\Parameter >>s >> >
