tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From karthikn <karthik.nanjang...@xius-bcgi.com>
Subject Re: JMX Perform GC TOMCAT 5.5.23
Date Thu, 05 Jun 2008 06:08:37 GMT
Hi

Pardon me for Re Posting the content ,  had posted the same  some day's ago
 

The Web application is simple and uses JNI to connect to UNIX LOCAL
Application

O/s = UNIX 11 PA Risc   2 CPU
SDK : J2SDK16
TOMCAT 5.5.23
RAM = 8 GB

JAVA_OPTS="-server -Xms200m -Xmx2548m -XX:+UseParallelGC -verbose:gc"

SERVER.xml

<!-- Define a non-SSL HTTP/1.1 Connector on port 8080 -->
    <Connector port="8080" maxHttpHeaderSize="8192"
               maxThreads="400" minSpareThreads="25" maxSpareThreads="75"
               enableLookups="false" redirectPort="8443" acceptCount="100"
               connectionTimeout="10000" disableUploadTimeout="true" />




Am i doing wrong anything in here.....

with regards
Karthik



Michael Simmons wrote:
> I havent used JMX so this might not be relevant
> But I'd suggest the following.
>
> 1) Install jvmstat it works with java 1.6 and use Visualgc to visual
> monitor the garbage collection.
>    Note: you need to run tomcat as the same user as the account running
> visualgc
>    use "jps" to find out the java vm ID
>
> 2) Use the server jvm (ie one in JAVA_HOME/jre/bin/server
>
> 3) Tweak your GC settings (try seeting your initial memory pool and Max
> mem pool to he same value (say 128MB) and your Thread stack size to say
> 32KB then add the a java options -XX:+UseConcMarkSweepGC -XX:NewSize=32M
> -XX:MaxNewSize=32M).
> Note on windows the Java options need to be on separate lines.
>
> Allocating more memory to the JVM isn't always best.
> Although it means the GC runs less often it causes it to take longer to
> run. Ie large pauses.
> Large pauses can cause timeouts resulting in retries causing more work
> resulting in more pauses and things go down hill from there.
>
> Ensure that your app is closing database connections as soon as it is
> finished with them and that error conditions are correctly handled such
> that database connections are aways closed.
> See "Random Connection Closed Exceptions" in
> (http://tomcat.apache.org/tomcat-6.0-doc/jndi-datasource-examples-howto.
> html)
> For template code.
>
> Michael Simmons
> Technical Advisor/Programmer
> Information Technology Services (ITS) (Office of Finance and Resources)
> Telephone: 6488 4792
> Fax: 6488 3861
> MBDP: M463
> Email: michael.simmons@uwa.edu.au
>
> -----Original Message-----
> From: karthikn [mailto:karthik.nanjangude@xius-bcgi.com]
> Sent: Wednesday, 4 June 2008 10:16 PM
> To: Tomcat Users List
> Subject: Re: JMX Perform GC TOMCAT 5.5.23
>
> Hi
>
> On a simulator System (same as Production ) with JMeter  Load test
>
> performance was good and CPU utilization  was not beyond 40%   for 900+
> users
>
> But for the same application in Production,
>
> We notice Constantly JAVA is  100% CPU utilization.
>
>
> Any Ideas ?
>
>
> with regards
> Karthik
>
>  we were able to
>
> Caldarale, Charles R wrote:
>   
>>> From: karthikn [mailto:karthik.nanjangude@xius-bcgi.com]
>>> Subject: Re: JMX Perform GC TOMCAT 5.5.23
>>>
>>> Reason : We have a Production TOMCAT 5.5.23 where in CPU
>>> Utilization for JAVA is going   100%  ,
>>>
>>>       
>> And for some reason you think a GC will fix that?
>>
>>
>>     
>>> This Tomcat needs to be restarted started every 12+ hrs We suspect HP
>>>       
>
>   
>>> supported JDK1.6 bing the culprit for the same
>>>
>>>       
>> A slight possibility, but in nearly all such cases, it's the
>>     
> application, not the JVM or Tomcat.
>   
>>  - Chuck
>>
>>
>> THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE
>>     
> PROPRIETARY MATERIAL and is thus for use only by the intended recipient.
> If you received this in error, please contact the sender and delete the
> e-mail and its attachments from all computers.
>   
>> ---------------------------------------------------------------------
>> To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe,
>> e-mail: users-unsubscribe@tomcat.apache.org
>> For additional commands, e-mail: users-help@tomcat.apache.org
>>
>>
>>
>>     
>
>
> ---------------------------------------------------------------------
> To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe,
> e-mail: users-unsubscribe@tomcat.apache.org
> For additional commands, e-mail: users-help@tomcat.apache.org
>
>
>
>
>   


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


Mime
View raw message