tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Marinko, Jeff" <>
Subject RE: Checking Tomcat's Memory
Date Fri, 16 Aug 2002 16:21:20 GMT
The box has 4GB of memory, and we can vary the swap space.  Tomcat
essentially can get as much memory as it wants, but the highest I've been
able to set the JVM is -Xmx1600m, anything higher and it complains (error
message was in a previous e-mail).  Although I think you are correct, on
Win32, 2GB is as high as we can go (unless someone can inform me otherwise).

-----Original Message-----
From: Kris Schneider []
Sent: Thursday, August 15, 2002 6:13 PM
To: Tomcat Users List
Subject: Re: Checking Tomcat's Memory

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):

"Sexton, George" wrote:
> I really doubt it. I seem to recall that for Windows 32 bit applications
> 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 []
> 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,
> 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
> 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 []
> Sent: Thursday, August 15, 2002 1:20 PM
> To: Tomcat Users List
> Subject: RE: Checking Tomcat's Memory
> s

Kris Schneider <>
D.O.Tech       <>

To unsubscribe, e-mail:   <>
For additional commands, e-mail: <>

View raw message