WebSphere Application Server v8.5 primer, part-5: Dynamic Cluster

A dynamic cluster is same like a static cluster except that WebSphere will control the no of active instances for an application, their placement by using service policies and work load demand.

WebSphere Application Server v8.5 primer, part-4: New Features (diagrams)

below diagrams are for your understanding of the new features of the WAS v8.5. I tried to simplify them and in that process some details are lost. However i’ll write a separate posts on each of the new features.

How WAS v8.5 is made ?


Application Edition Management


Health Management


On-Demand Router (ODR)

Dynamic Clusters

WebSphere Application Server v8.5 primer, part-2: Installation

WebSphere Application Server v8.5 uses IBM installation manager (IIM) for installation.  If you are new to Installation Manager, please go trough my old post on IIM

The installation process is not changed from the previous version (WAS v8.0), so please check the previous post of WASv8 installation,


WAS v8.5 ND trail Download

This trial has all features enabled. Download the trial for an evaluation period of 60 days.

WebSphere Application Server v8.5 primer, part-1: What’s New

Alright .. we are starting this new series on WebSphere Application Server v8.5, which has some new and very good features.

There are quiet a good amount articles available on internet about what’s new in WAS v8.5, so iam not going to write them again. So below are some of the references/links that i think will be helpful for you on this topic.

Websphere application server (WAS) – Thread dump and Heap Dump

When to generate ? How to generate ? how to debug ?

Thread Dumps
If you get unexplained server hangs under WebSphere, you can obtain, from the WebSphere server, a thread dump to help diagnose the problem.

In the case of a server hang, you can force an application to create a thread dump.

On unix/Linux machines find the process id (PID) of the hung JVM and issue kill -3 PID.  Look for an output file in the installation root directory with a name like javacore.date.time.id.txt.
Using wasadmin prompt,
get the handle of the server
wsadmin>set jvm [$AdminControl completeObjectName type=JVM,process=server1,*]
wsadmin>$AdminControl invoke $jvm dumpThreadsRead More »

dynamic cache in WebSphere

Dynamic Cache supports caching of Java servlets, JavaServer Pages (JSP), WebSphere command objects, Web services objects, and Java objects.

*  The concept of caching static information in a browser, proxy or a webserver provides an effective way to reduce network and processing requirements. A larger overhead of many web applications is related to the serving, not of static content, but of dynamic content based on user input and retrieval of data from backend resources such as databases.

How to enable Dynamic Cache
*  Dynamic cache is enabled by default on V6.1 WebSphere AppServers.
*  To enable Servlet and JSP caching from the admin console, navigate to the web container
Servers –> Application Servers -> <select server> -> webcontainer settings –> webcontainer
*  Check ‘Enable servlet caching’
*  Save and restart the Application Server to put the changes into effect.

Specify what to be catched
– Now servlet caching is enabled, if is necessary to define which dynamic content will be cached and the rules by which it will be cached or invalidated. servlet and JSP caching will be policy based using the cachespec.xml file. The preferred location for the cachespec.xml file is within the web applications WEB-INF folder.Read More »