Hi,
http://java.sun.com/performance/jvmstat/
jvmstat 3.0 can monitor J2SE 5.0, J2SE 1.4.2 and J2SE 1.4.1
The jvmstat technology adds light weight performance and configuration
instrumentation to the HotSpot JVM and provides a set of monitoring APIs
and tools for monitoring the performance of the HotSpot JVM in production
environments. The instrumentation is designed such that it is 'always on',
yet has negligible performance impact. The monitoring interfaces added to
the HotSpot JVM are proprietary and may or may not be supported in future
versions of the HotSpot JVM.
Util for JAMES-592 and/or memory use measurement?
bye,
Guillermo
----- Original Message -----
From: "Serge Knystautas" <[EMAIL PROTECTED]>
To: "James Developers List" <server-dev@james.apache.org>
Sent: Sunday, October 08, 2006 5:03 AM
Subject: James stack size
On a recent project, we were trying to justify tuning the stack size
down on the app tier. Here's what I found:
Default in Sun JDK 1.2 was 128kb
Default in Sun JDK 1.3 was 256kb
Default in Sun JDK 1.4 on windows is 512kb
Default in IBM JDK 1.5 is 256kb on all platforms
(http://tinyurl.com/gbfd4)
Default in JRockit JDK 1.5 is 64k (win) or 128kb (linux)
(http://tinyurl.com/kapbp)
The old volano chat scalability reports used 32kb
The kicker is that Sun JDK 1.5 on unix uses the ulimit stack size
setting. So my James instance with its ulimit stack size of 8192kb
and 131 threads.... that's roughly 1 GB of memory used by James just
for its silly threads. No wonder this box is churning the swap space!
Anyway, I've restarted my James instance stack size down to 256k
(-Xss256k) and isn't failing so far. Hopefully could be a nice
recommendation to put somewhere. In fact with James architecture that
is thread heavy but very stack shallow (assuming you're not running
JNI stuff in some mailet), we could probably make the stack size even
smaller.
Just 2 cents for the night.
--
Serge Knystautas
Lokitech >> software . strategy . design >> http://www.lokitech.com
p. 301.656.5501
e. [EMAIL PROTECTED]
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