Re: [ajug-members]: Increasing JVM heap beyond 1.3GB in Win2K

["Joe Sam Shirah" <jshirah@attglobal.net>]

    Hi Barry,

    Brian Sumner's reply pretty much sums things up.

    There's a HotSpot FAQ ( that's showing some age ) at

http://java.sun.com/docs/hotspot/PerformanceFAQ.html

and your question specifically is at "With 1.3.1 we got 4GB heaps on
Solaris, why can't I get this to work on Windows?"

http://java.sun.com/docs/hotspot/PerformanceFAQ.html#22

    You may also want to look at the Java Filter Forum question "JVM and
memory" at

<http://www-106.ibm.com/developerworks/forums/dw_expandTree.jsp?thread=30656
&forum=177&cat=10&message=1495457#1495457>

It has links to articles about HotSpot and GC for Sun and IBM VMs that
include tuning parameters and conditions for returning memory to the OS.  I
believe the Sun article updates the J2ME link you mentioned.  It looks like
http://www,java.sun.com is mostly back up so you should be able to hit the
links now.  HTH,


                                                         Joe Sam

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----- Original Message -----
From: "Barry Hawkins" <ly5t5@allthingscomputed.com>
To: "AJUG Members List" <ajug-members@ajug.org>
Sent: Tuesday, March 02, 2004 3:39 PM
Subject: [ajug-members]: Increasing JVM heap beyond 1.3GB in Win2K


> List,
> Has anyone successfully managed to get a JVM heap size on Windows 2000
> using the Sun 1.4.2 JVM?  Our team has a web app in ColdFusion MX
> (CFMX) (long story, stay with me on the JVM thing) which runs on an OEM
> version of Macromedia JRun 4.  JRun uses the 1.4.2 JDK on Windows 2000,
> and Macromedia recommends setting the JVM to have a minimum and maximum
> JVM heap size of 1024MB.  They also recommend tweaking the JVM settings
> if you need to.  However, they offer very little advice on doing that,
> and the advice they do give contains broken links to J2ME resources.
> The JVM heap size for our app is nailed at an average of 1,473,910,395
> bytes or ~1.36GB.  Stuff I have found with Google and on the Apple Java
> mailing list indicate that the Sun JVM on Win2K will only get to about
> 1.3 - 1.6GB.  Has anyone been able to successfully get a heap size
> larger than that on Win2K?
> Along those lines, what JVMs are folks using on their production
> servers in general?  Which JVMs tend to get along with which app
> servers?  I'd love to hear your input.
>
> Thanks,
> --
> Barry C. Hawkins
> All Things Computed
> site: www.allthingscomputed.com
> weblog: www.yepthatsme.com
>