FWIW, this has been fixed for Tomcat 3.2.2 higher. You'll now get the 404
error instead of the tight loop.
-----Original Message-----
From: Kelly Kleinfelder [mailto:[EMAIL PROTECTED]]
Sent: Friday, February 16, 2001 11:33 AM
To: [EMAIL PROTECTED]
Subject: SOLVED: runaway threads eating cpu cycles on Solaris 7
found this snippet as a comment in the tomcat cvs repository.....
+6.11 Misconfiguration Can Cause CPU-Bound Loop
+
+If you misconfigure Tomcat 3.2 in a way that there is no valid context to
+handle a request (such as removing the root context and then attempting a
+request that should be handled by that context), Tomcat will enter a
CPU-bound
+loop instead of responding with a 404 error.
I had removed the default contexts since all of our applications are stored
in a different directory structure and aliased in our configuration files.
Kelly
----- Original Message -----
From: Kelly Kleinfelder
To: [EMAIL PROTECTED]
Sent: Thursday, February 15, 2001 3:43 PM
Subject: runaway threads eating cpu cycles on Solaris 7
We are running Tomcat 3.2.1 and Solaris 7 on a Sun e250 with 4 400Mhz
processors. The problem we're having is that one thread is chewing up the
majority of the cpu cycles and sometimes causes tomcat to hang.
I have included sample mpstat data and the output from ps -L -p PID:
ps -L -p 26361
PID LWP TTY LTIME CMD
26361 1 ? 0:03 java
26361 22 ? 1:02 java
26361 23 ? 40:57 java
26361 24 ? 1:43 java
26361 26 ? 0:09 java
26361 67 ? 0:03 java
(24 entries deleted for brevity. All were at 0:00 LTIME)
mpstat 30
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 12 0 12 6 4 17 0 1 0 0 75 0 3 1 96
1 6 0 6 4 1 14 3 0 0 0 52 59 1 1 39
2 0 0 0 64 62 12 2 0 0 0 20 41 1 1 57
3 4 0 14 203 3 27 0 1 0 0 26 0 0 0 100
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 0 0 1 3 2 16 0 1 1 0 51 1 3 1 95
1 0 0 0 5 1 6 4 0 0 0 3 81 0 0 19
2 0 0 2 19 19 17 0 1 0 0 16 0 0 0 100
3 4 0 13 202 2 15 1 1 0 0 41 19 2 0 78
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 4 0 5 5 5 17 0 1 1 0 70 1 2 1 96
1 4 0 0 5 1 11 4 0 0 0 36 84 0 0 15
2 2 0 4 26 26 28 0 1 0 0 81 2 0 0 98
3 0 0 20 204 4 19 1 0 0 0 24 14 0 0 86
Before today, this was happening about every 3 days. Today it happened 5
hours apart. By going through our logs, we have determined that this is not
caused by any specific user action. It is also not caused by server load, as
it mostly happens with less than 5 users accessing the application. It is
also not a gradual thing. Our sar statistics show that our processor idle
time is 98% and then 5 minutes later it's down to 83% and in another 5
minutes, it's at 49%.
Is there any way that I can tell exactly what is happening in the offending
thread?
Any other ideas on what's causing this problem?
Thanks,
Kelly
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