JVM Profilers

[Roman Fail <rf...@posportal.com>]

I am considering purchase of JProfiler, OptimizeIt 5.5, or JProbe.  Does anyone have wisdom to share on the features of each?  Are there other good profilers I should consider?
 
We have been experiencing regular JVM crashes on our production Tomcat 4.1.24 installation.  Originally we were running the Sun HotSpot 1.4.1_02 client, then server (on RH Linux 8.0).  Now we've switched to BEA JRockit 8.1 and are still having crashes, clearly something is bad in our code - or perhaps we need to start load-balancing.  We have tuned obvious kernel parameters like file-max, and have 2GB physical memory (1GB is given to tomcat's heap), dual Intel processors.  Besides a few small Java-based daemons on the server, it is dedicated to tomcat.
 
We recently migrated from a Windows 2000/ServletExec 3.1/Sun HotSpot client 1.3.1 environment which didn't have these problems - I'm not sure what to think at this point.  
 
Please reply directly to me (and cc the list) as I receive only the digest version.
 
Thanks!
 
Roman Fail
POS Portal, Inc.
Sacramento, CA USA

Re: JVM Profilers

["Eric J. Pinnell" <er...@iCky.org>]

Something to think about is whether or not you are trying to debug a
production system or a dev system.  Does it crash in dev or do you only
see if after a few days being up in prod?

If you only see it in prod, you might want to think about something a
little more lightwieght than the profilers you mention.  Those are mainly
for developers.  And as far as the ones you name off it's really personal
preference.

There is a flavor of profilers that are made for more production envs.
An example is RootCause.  But there are several of those types of
profilers out there.

-e

On Wed, 11 Jun 2003, Roman Fail wrote:

> I am considering purchase of JProfiler, OptimizeIt 5.5, or JProbe.  Does anyone have wisdom to share on the features of each?  Are there other good profilers I should consider?
>
> We have been experiencing regular JVM crashes on our production Tomcat 4.1.24 installation.  Originally we were running the Sun HotSpot 1.4.1_02 client, then server (on RH Linux 8.0).  Now we've switched to BEA JRockit 8.1 and are still having crashes, clearly something is bad in our code - or perhaps we need to start load-balancing.  We have tuned obvious kernel parameters like file-max, and have 2GB physical memory (1GB is given to tomcat's heap), dual Intel processors.  Besides a few small Java-based daemons on the server, it is dedicated to tomcat.
>
> We recently migrated from a Windows 2000/ServletExec 3.1/Sun HotSpot client 1.3.1 environment which didn't have these problems - I'm not sure what to think at this point.
>
> Please reply directly to me (and cc the list) as I receive only the digest version.
>
> Thanks!
>
> Roman Fail
> POS Portal, Inc.
> Sacramento, CA USA
>
>

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Re: JVM Profilers

[Yoav Shapira <yo...@yahoo.com>]

Howdy,

> I am considering purchase of JProfiler, OptimizeIt 5.5, or JProbe.  Does
> anyone have wisdom to share on the features of each?  Are there other good
> profilers I should consider?

I like OptimizeIt, having used them all.  But the features are fairly similar. 
A Profiler is a key tool I highly recommend using frequently.

However, profilers are not designed for production use.  They will require much
more memory (often an order of magnitude) and slow down the system (again,
often by an order of magnitude or more) when running.  For production, there's
no substitute for good logging that you can control at runtime, e.g. log4j.

> We have been experiencing regular JVM crashes on our production Tomcat 4.1.24

What does the hs_err file say?

> installation.  Originally we were running the Sun HotSpot 1.4.1_02 client,
> then server (on RH Linux 8.0).  Now we've switched to BEA JRockit 8.1 and are
> still having crashes, clearly something is bad in our code - or perhaps we

Maybe you need to try on a different OS?  A different linux kernel?  On
Solaris, for example, you will get JDK crashes unless you download the Sun OS
patches for the JDK.

> We recently migrated from a Windows 2000/ServletExec 3.1/Sun HotSpot client
> 1.3.1 environment which didn't have these problems - I'm not sure what to
> think at this point.  

And the code didn't change, right?  You only migrated do a different OS and a
different VM?

> Please reply directly to me (and cc the list) as I receive only the digest
> version.

Use the archives ;)  I like the ones at AIMS.

Yoav Shapira


=====
Yoav Shapira
yoavs@computer.org

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