[Fwd: Re: java crashing when load average is high]

[Jon Kuster]

Forwarding this to -amd64 for a slightly wider audience since I'm not
sure if it's a java issue, or an amd64 issue.  We've since upgraded to
-stable.

Thanks,
Jon

-------- Forwarded Message --------
From: Jon Kuster <kwsn at earthlink.net>
Reply-To: kwsn at earthlink.net
To: Toby Murray <toby.murray at gmail.com>
Cc: freebsd-java at freebsd.org
Subject: Re: java crashing when load average is high
Date: Sun, 17 Apr 2005 17:36:30 -0700

On Sun, 2005-04-17 at 14:06 -0500, Toby Murray wrote:
> Hi,
> 
> I am working on getting a new server online.  It is a Dell Poweredge
> with dual HT Xeons and 1GB of RAM.  We are running FreeBSD 5.4-RC1 and
> java 1.4.2_08.

Since I'm also helping Toby get this server online, I should note that
we're running the amd64 version of RC1 and the linux-sun-jdk14.

FreeBSD ni 5.4-RC1 FreeBSD 5.4-RC1 #0: Thu Apr 14 11:34:58 EDT 2005
ruessda at ni:/usr/obj/usr/src/sys/NISMP  amd64

> java version "1.4.2_08"
> Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_08-b03)
> Java HotSpot(TM) Client VM (build 1.4.2_08-b03, mixed mode)
> 
> I have a java program that reads XML files over an HTTP stream and
> inserts data from them into a mysql database.  After getting java up
> and running everything appeared to be working normally at first and
> the program ran fine.  But then I tried running it while something
> else was compiling and the load average was up around 5 or 6. 
> Suddenly the behavior of the JVM became extremely erratic.
> 
> Sometimes the whole JVM dumps with a signal 11 and leaves the following in dmsg:
> kernel trap 12 with interrupts disabled
> Other times the program throws random exceptions.  I have seen 5 or 6
> different exceptions being thrown at seemingly random places in the
> code while parsing the same data.
> 
> A third behavior is for java to go into what appears to be an infinite
> loop somewhere.  Usually when my program runs, there is one java
> thread and one mysql process that each take up ~70% of one CPU.  When
> things start looping, 2 java processes start sucking up as much CPU as
> they can and mysql drops to nothing.  This continues until I pull out
> the kill -9.
> 
> So to summarize it all:
> java works fine if it is the only thing running
> If the box is already  under load, java malfunctions in one of 3 ways:
>  Signal 11, random Exception thrown or it starts looping without
> getting anything done.
> 
> Any clues?  I see several other threads on the list about signal 11
> problems but I didn't see anything about the problems being related to
> load.  Let me know if you need more info on something.
> 
> Thanks,
> Toby