Almost all threads are in "P" status

[止观梅 <ne...@gmail.com>]

Hi,

I'm encountering a problem:
1. almost all threads are in "P" status, and occasionally there is 1 or 2
in "S" or "R" status,
2. and there is no slow query on MySQL side, because I can't catch any
process with command "show full processlist",
3. while tomcat connection rate is merely less than 30req/s,
4. and tomcat CAN response correct result page in acceptable time(1 second)
System architecture: Tomcat*3 + Memcached*2 + MySQL-Proxy*2 + MySQL*2,
Linux-Redhat
Software information: apache-tomcat-7.0.6, MySQL--5.5.11-1.rhel5.x86_64,
jdk-6u23-linux-x64-rpm
Configuration:
tomcat server.xml:

   1. <Connector port="8080" protocol="HTTP/1.1"
   2.            connectionTimeout="20000"
   3.            redirectPort="8443" />


which provides default maximum number of threads is 200

Screenshot: please refer to attachment.

Question:
1. is this situation(full of "P" status) problematic?
2. how to explain the situation?(waiting for Http request body? sounds
unreasonable!)

Re: Almost all threads are in "P" status

[Christopher Schultz <ch...@christopherschultz.net>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

止观梅,

On 2/14/12 3:12 AM, 止观梅 wrote:
> I'm encountering a problem: 1. almost all threads are in "P"
> status, and occasionally there is 1 or 2 in "S" or "R" status,

Are you talking about looking at the threads in 'top' or somewhere
else? Java thread dumps usually say something like "RUNNING" as their
status, and 'top' (on Linux) doesn't have a 'P' state. So, what are
you talking about?

> 2. and there is no slow query on MySQL side, because I can't catch
> any process with command "show full processlist",

Oh, so you're running MySQL? Are you talking about OS threads or Java
threads?

> 3. while tomcat connection rate is merely less than 30req/s,

Oh, good. Tomcat is somewhere in this mix.

> 4. and tomcat CAN response correct result page in acceptable time(1
> second)

Great.

> Software information: apache-tomcat-7.0.6

You seriously need to upgrade: 7.0.6 was the first non-beta version of
Tomcat 7.0.x and many many things have been fixed since then. Current
version is 7.0.25.

> Screenshot: please refer to attachment.

Images are stripped from posts. Please either ZIP the screenshot
(sometimes works), post the screnshot somewhere like dropbox and give
us a link, or try to describe what the screenshot shows.

> Question: 1. is this situation(full of "P" status) problematic?

That depends on what 'P' means. If it means "*P*erfectly Fine" then I
suspect things are okay.

> 2. how to explain the situation?(waiting for Http request body?
> sounds unreasonable!)

If you want to know what Tomcat is doing, take a thread dump.
http://wiki.apache.org/tomcat/HowTo#How_do_I_obtain_a_thread_dump_of_my_running_webapp_.3F

- -chris
-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2.0.17 (Darwin)
Comment: GPGTools - http://gpgtools.org
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAk86l7MACgkQ9CaO5/Lv0PDrkQCfQB3eZC0lhG692mIcDHVcgru3
5coAmgJC+QzsmTKi9c4qiqrBvHt+t5c0
=02Bm
-----END PGP SIGNATURE-----

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
For additional commands, e-mail: users-help@tomcat.apache.org