If you search for LD_KERNEL and my name on google, you will see that I was part of a discussion a while back that was glad to find that out.
Daniel Gibby
Oscar Carrillo wrote:
Hi,
Saw your message on the boards.
Did you make sure you have this environment variable set?
On systems that I need it, I put it in my tomcat startup file.
LD_KERNEL_ASSUME="2.2.5"
Check out my howto page for my brief notes on threading and it's potential problems with JVMs and threads.
http://www.linuxjava.net/howto/webapp/
Oscar
On Tue, 17 Feb 2004, Daniel Gibby wrote:
My tomcat 4.1.29 instance running J2RE 1.4.1 IBM build cxia321411-20030930 on RedHat 9 kernel 2.4.18-14
keeps gaining processor usage until finally can't answer requests successfully.
The machine has a relatively light load.
I did a kill -3 on the process that showed up on top and got a stack trace... the problem is I have no idea how to analyze the thread dump to see what is consuming CPU.
I'm sure something must be spinning its wheels, but I don't know how to tell... I can just see that when I run top my tomcat process has 99.9 % of the CPU and the load average is 8.00 8.00 8.00
I've fixed problems in the past on a separate java application (not tomcat) where I can tell what the problem is in the thread dump because a thread waiting to be notified is also the one that has a lock on it to notify the thing that is waiting to notify it... (that didn't make sense, I know... but anyway it is basically a circle where it won't ever get woken up.)
However, in this tomcat case, I can't see anything like that where something is waiting in circles... even though I wouldn't rule that out. My experience on reading thread dumps is limited... Anyway, can someone who has better experience tell me what is consuming the CPU? Restarting tomcat brings the load back down, and it slowly goes up again... like over a few days to a weeks time it is back up to 8.00 Load Average.
I won't include the whole file. I trimmed the file down to 1350 lines by getting rid of a lot of 2HPMEMMAPLINE lines and the section titled:
0SECTION CL subcomponent dump routine
but I think that is still too long to post here.
I'm hoping that someone can tell me what to include and what to exclude and I'll reply with the appropriate parts of the dump.
Thanks, Daniel
NULL ------------------------------------------------------------------------
0SECTION TITLE subcomponent dump routine
NULL ===============================
1TISIGINFO signal 3 received
1TIDATETIME Date: 2004/02/17 at 08:53:22
1TIFILENAME Javacore filename: /tmp/javacore.20040217.085322.23429.txt
NULL ------------------------------------------------------------------------
0SECTION XHPI subcomponent dump routine
NULL ==============================
1HPTIME Tue Feb 17 08:53:22 2004
1HPSIGRECV SIGQUIT received in ?? at (nil) in ??.
1HPFULLVERSION J2RE 1.4.1 IBM build cxia321411-20030930
NULL
1HPOPENV Operating Environment
NULL ---------------------
2HPHOSTNAME Host : somehost.com.(none)
2HPOSLEVEL OS Level : 2.4.18-14.#1 Wed Sep 4 13:35:50 EDT 2002
2HPLIBCVER glibc Version : 2.2.93
2HPCPUS Processors -
3HPARCH Architecture : (not implemented)
3HPNUMCPUS How Many : (not implemented)
3HPCPUSENABLED Enabled : 1
NULL
1HPMEMINFO Memory Info
NULL -----------
2HPMEMLINE total: used: free: shared: buffers: cached:
2HPMEMLINE Mem: 1055625216 1015181312 40443904 0 83464192 614227968
2HPMEMLINE Swap: 1052827648 929792 1051897856
2HPMEMLINE MemTotal: 1030884 kB
2HPMEMLINE MemFree: 39496 kB
2HPMEMLINE MemShared: 0 kB
2HPMEMLINE Buffers: 81508 kB
2HPMEMLINE Cached: 599596 kB
2HPMEMLINE SwapCached: 236 kB
2HPMEMLINE Active: 552968 kB
2HPMEMLINE Inact_dirty: 344020 kB
2HPMEMLINE Inact_clean: 50304 kB
2HPMEMLINE Inact_target: 189456 kB
2HPMEMLINE HighTotal: 130880 kB
2HPMEMLINE HighFree: 1024 kB
2HPMEMLINE LowTotal: 900004 kB
2HPMEMLINE LowFree: 38472 kB
2HPMEMLINE SwapTotal: 1028152 kB
2HPMEMLINE SwapFree: 1027244 kB
2HPMEMLINE Committed_AS: 1067972 kB
NULL
1HPUSERLIMITS User Limits (in bytes except for NOFILE and NPROC) -
NULL -----------
2HPUSERLIMIT RLIMIT_FSIZE : infinity
2HPUSERLIMIT RLIMIT_DATA : infinity
2HPUSERLIMIT RLIMIT_STACK : 2093056
2HPUSERLIMIT RLIMIT_CORE : 0
2HPUSERLIMIT RLIMIT_NOFILE : 1024
2HPUSERLIMIT RLIMIT_NPROC : 7168
NULL
1HPSIGHANDLERS JVM Signal Handlers
NULL -------------------
2HPSIGHANDLER HUP : unknown handler
2HPSIGHANDLER INT : unknown handler
2HPSIGHANDLER QUIT : unknown handler
2HPSIGHANDLER ILL : unknown handler
2HPSIGHANDLER TRAP : unknown handler
2HPSIGHANDLER ABRT : unknown handler
2HPSIGHANDLER FPE : unknown handler
2HPSIGHANDLER KILL : default handler
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