We are trying to deploy 2 versions of the same application on Tomcat 7 to test its parallel deployment features for our application.

Not meeting with success, I was looking for  a definitive guide for parallel deployment on Tomcat 7.

Our application is a JSP based application but we can have changes often.

asked by csaoin

The definitive reference for parallel deployment comes directly from the Apache Software Foundation: http://tomcat.apache.org/tomcat-7.0-doc/config/context.html#Parallel_deployment.

Additionally, Mark Thomas wrote a summary article explaining how this feature works on the Context Container and across clusters: http://www.tomcatexpert.com/blog/2011/05/31/parallel-deployment-tomcat-7.

answered by SpringSource on January 6, 2012 07:13 AM

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Need to configure a linux (RedHat AS4) Tomcat 6.0.32 server's memory settings. After reviewing numerous guides about confiugring tomcat's memory, I realized I am seriously confused.  I attempted to configure the heap memory by adding setenv.sh file to the /opt/apache-tomcat-6.0.32/bin folder.  Here is the content of setenv.sh file.
      export CATALINA_OPTS="-Xms768m -Xmx768m"

asked by chill

You are on the right track.

You have...

 - created "bin/setenv.sh"
 - exported the CATALINA_OPTS environment variable
 - added the settings to configure the initial and max heap values to 768m

You just need to...

  - add -XX:PermSize and -XX:MaxPermSize to CATALINA_OPTS to configure PermGen to be 512M.
  - add -XX:NewSize and -XX:MaxNewSize to CATALINA_OPTS to configure YoungGen to be 200M.
  - restart your Tomcat instance

One note, unless you really, really know what you are doing I wouldn't recommend explicitly configuring the size of the YoungGen space.  The JVM does a great job of sizing this automatically.  Unless you have done some serious load testing on your application or you have been given exact instructions by a 3td party vendor, I would suggest just using the defaults.

Lastly, there are a couple ways that you can confirm that your settings are working.

1.) Run "ps aux | grep catalina" (or some other version of the "ps" command).  Look at your Tomcat process.  You should see all of the options that you've put into CATALINA_OPTS (and many more) included on the command line for your process.  If you see them listed here then they are active.

2.) Connect to Tomcat with "jconsole", click the "VM Summary" tab and look at the "VM arguments" section.  Again, you should see the options that you added to CATALINA_OPTS listed here.

3.) Run "jinfo <tomcat-pid>".  The last thing it prints will be the VM Flags.  These should include the options that you've specified in CATALINA_OPTS.


Lastly, I would suggest that you read these two articles.  This is more than just a shameless plug for my posts .  They were written to gently introduce people to the concepts of JVM tuning (for Tomcat).  Furthermore, when you feel that you understand the topics presented in the article, you can progress along to the more advanced articles in the links.  This gentle progression should help take some of the confusion out of JVM tuning.

  http://www.tomcatexpert.com/blog/2011/11/16/setting-measurement-garbage-collection-apache-tomcat
  http://www.tomcatexpert.com/blog/2011/11/22/performance-tuning-jvm-running-tomcat

Hope that helps!

answered by dmikusa on January 10, 2012 07:32 AM

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Is it possible to create and modify global connection pool on the fly?

I want do be able to deploy new applications using new global connection pool without restart tomcat. I don't want to use context.xml file in my applications.

The article http://www.tomcatexpert.com/blog/2010/04/01/configuring-jdbc-pool-high-concurrency shows how to create global connection pool configuring conf/server.xml file, but I don't know how to reflect change without restarting tomcat.

asked by persapiens

Is it possible to create new resources (as in <GlobalNamingResources><Resource .../></GlobalNamingResources>) at runtime?  No.  To create new global resources you need to modify "conf/server.xml" and restart Tomcat.

Is it possible to modify existing global resources?  It depends.  Some resources expose properties via JMX and those properties can be modified through jconsole.  If your resource exposes the properties that you need to modify then you should be able to update them at runtime.

Typically, when you need to be able to modify a resource without restarting Tomcat you would define that in your Context.  That way you can make changes to the Context, redeploy your application and see the changes all without restarting Tomcat.

answered by dmikusa on January 20, 2012 05:05 AM

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Our configuration consists of the following components (all of them are running on a single Windows Server 2003 machine):

• Apache Web Server - version 2.2.16 (with mod_jk version 1.2.31)
• Tomcat Server - version 5.5.30

We are load testing the server with relatively simple requests.
It seems that under load (~8000 requests we are sending per minute from our load simulator) - we have a delay between apache web server and the mod_jk component.

asked by nir.zilberman

Make sure you configure both Apache httpd and mod_jk to handle the traffic.

This means, the number of threads(workers) that httpd has will impact your system.

Also, in high concurrency, how you configure KeepAlive is important. There is a chance that Apache is using its threads waiting for the next request on idle connections, while active connections are not being handled. 

Posting your configuration files may be a good idea.

best

Filip

answered by fhanik on June 15, 2011 07:09 PM

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