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From Christopher Schultz <>
Subject Re: Need help in understanding tomcat thread dump
Date Tue, 11 Jan 2011 16:57:13 GMT
Hash: SHA1


On 1/11/2011 7:11 AM, Amol Puglia wrote:
> The major issue is [Apache httpd] process is going very high and not
> coming down.

If you mean that the CPU is experiencing high load, then the thread
below is unlikely to be the cause:

> "TP-Processor50" daemon prio=5 tid=0x00449ea8 nid=0x56 waiting on condition [9427e000..9427fc30]
>     at java.lang.Thread.sleep(Native Method)
>     at
>     at javax.servlet.http.HttpServlet.service(
>     at javax.servlet.http.HttpServlet.service(

Why? Because Thread.sleep doesn't use CPU time: it blocks waiting for a
signal from the CPU saying that it's time to wake up. It's still
possible this is the problem, if the Thread.sleep() call is in a loop
without much of a sleep, like this:

while(true) {

That would peg your CPU.

Why not look at the code in at line
506 and see what's going on?

> Is it porblem in a backend tomcat server or it has to do something
> with apache itself.?

That depends on what the problem is :)

> tomcat version :- 5.5.9

You need to upgrade, but that's not causing your CPU load.

You need to use a tool such as top to find out which process is using
all your CPU: once you determine if it's Tomcat (process will be "java")
or Apache httpd (process will be "apache2" or "httpd" depending on your

- -chris
Version: GnuPG v1.4.10 (MingW32)
Comment: Using GnuPG with Mozilla -


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