Thanks.
I got the dump of the running JVM (only the benchmark is running at dump
time).
I tried to take a look at it, but as am not familiar with java, I prefer
talk about it here.
-first I noticed the number of TP-Processor is twice the number of
concurrent resquests send by ab (why twice? i don't know).
About half of them are in Object.wait state
"TP-Processor40" daemon prio=1 tid=0xdef53168 nid=0x646f in
Object.wait() [0xda729000..0xda7291b8]
at java.lang.Object.wait(Native Method)
- waiting on <0xe17bc808> (a
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable)
at java.lang.Object.wait(Object.java:429)
at org.apache.tomcat.util.threads.ThreadPool
$ControlRunnable.run(ThreadPool.java:661)
- locked <0xe17bc808> (a
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable)
at java.lang.Thread.run(Thread.java:534)
and the other half is waiting for a monitor entry.
"TP-Processor34" daemon prio=1 tid=0xdef3edc0 nid=0x6469 waiting for
monitor entry [0xdaa28000..0xdaa291b8]
at java.sql.DriverManager.getConnection(DriverManager.java:158)
- waiting to lock <0xeff0b350> (a java.lang.Class)
at
com.mana.oc.DBConnection.getConnectionCRM(DBConnection.java:155)
at org.apache.jsp.Login_jsp._jspService(Login_jsp.java:192)
......
And only 5 runnable processors.
To me this sounds like a pool of database connection that is full but
I'm not sure of it and I don't really know how/where to deal with it.
If someone has the kind willing to take a look at the full dump here it
is: http://pastebin.com/2v3PVTDm
Regards
Le jeudi 26 août 2010 à 21:36 +0200, Rainer Jung a écrit :
> On 26.08.2010 21:00, Alexandre Chapellon wrote:
> > Le jeudi 26 août 2010 à 09:25 +0200, Rainer Jung a écrit :
> >
> >> On 26.08.2010 03:28, Alexandre Chapellon wrote:
> >>> Hello,
> >>>
> >>> I'm quite new to tomcat and have an old webapps running on tomcat 4.1
> >>> and jvm 1.4.2 with apach2.2 in front ofthem (using modjk).
> >>> I'm trying to get ready for a comming pick load I will have to face.
> >>> I Try to do some benchmark using ab and the jkstatus worker.
> >>> Whatever the configuration of my connecter (both on the apache or tomcat
> >>> side) I never go upper than 20 requests / second.
> >>> Here are few parameters I changed in order to get better performances:
> >>>
> >>> -Apache2 (worker):
> >>> increased ServerLimit (64), ThreadLimit (256), MaxClients (2048),
> >>> ThreadsPerChild (128)
> >>> set to a non zero value MaxRequestsPerChild (500)
> >>>
> >>> - modjk (1.2.30):
> >>> set to non-zero value worker.selfcare.connection_pool_timeout=60
> >>>
> >>> -Tomcat AJP13 Connector:
> >>> acceptCount="50" enableLookups="false" maxProcessors="500"
> >>> bufferSize="4096" socketBuffer="20000"
> >>>
> >>> Unfortunately this doesn't help and am still stuck with 20req/s when the
> >>> machines' load is not that high and 60% of CPU at most is used during
> >>> stress test.
> >>> I've googled around but can't find anything else about increasing
> >>> performances of apache/tomcat... Help much appreciated
> >>>
> >>> Regards
> >>>
> >>> P.S: right now am using ab to send 2000 request with 50 concurrents.
> >>
> >> Take thread dumps of the Tomcat JVM and check what your applicaion is
> >> actually doing (like waiting for locks or externals components).
> >>
> >
> >
> > This sounds an excellent idea indeed, and it's surely what I would have
> > done if I new it was possible and how I could do it :)
> > What's the way to do it?
>
> http://wiki.apache.org/tomcat/HowTo#How_do_I_obtain_a_thread_dump_of_my_running_webapp_.3F
>
> Regards,
>
> Rainer
>
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