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

[Jon Kuster]

On Mon, 2005-04-18 at 13:03 +0200, Ernst W. Winter wrote:
> On Mon, 18 Apr 2005, Jon Kuster wrote:
> 
> > 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.
> > 
> I will try to give some explanation to the text below, from what I
> have a experience with something similar.
> 
> > Thanks,
> > Jon
> > 
> You're welcome
> 
> Ernst
> 
> > -------- 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.
> > 
> You can also use java 1.5 as it compiles and instlls as well works on
> amd64. I have done a "make isntall clean" on 3 machiens so far, There
> are some small hitches but you can find it in the newsgroup or mail
> me directly.

I thought about that, but I haven't been able to get jdk15 to build yet.
If you could send me the info about the hitches, that would be great.

> > 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.
> > > 
> well we had the same problem with a clients machien here, although it
> was php and mysql, it froze the HD complete and no access possible
> only switching of the machine.

The machine remains responsive, it's just that java acts strangely.

> 
> > > 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.
> > > 
> This is what happen as i explained above.
> 
> > > 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.
> > > 
> well the only thing I could suggest is that you check out if it is a
> "loop" to mysql, which has happen in our clients case that caused
> that behaviour. Otherwise I have no explanation than that. If you eed
> more information, then let me know and I send you the email of the
> person that handled this.
> 
> > > Thanks,
> > > Toby
> 
> Ernst
>