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All Things WebSphere

Concerns and issues relating to all versions of WebSphere Application Server

Wednesday, September 19, 2012

 

It's official now - WAS 6.1 extended to 2013

Hot off the press:  IBM extends the end-of-service date for IBM® WebSphere® Application Server V6.1 from September 30, 2012, to September 30, 2013. This includes the following programs below. IBM will be supporting WAS v6.1 for 7 years since GA date, which is beyond our standard 5 year policy.  So, no need to sign the extended support contract!

5724-J08 6.1.0 IBM WebSphere Application Server
5724-I63 6.1.0 IBM WebSphere Application Server - Express
5724-H88 6.1.0 IBM WebSphere Application Server Network Deployment
5724-H89 6.1.0 IBM WebSphere Application Server for Developers
5724-X89 6.1.0 IBM WebSphere Application Server Hypervisor Edition V6.1 for Novell SLES
5725-A25 6.1.0 IBM WebSphere Application Server Hypervisor Edition V6.1 for AIX
5725-C00 6.1.0 IBM HTTP Server for WebSphere Application Server Hypervisor Edition V6.1 on Novell SLES
5725-C01 6.1.0 IBM HTTP Server for WebSphere Application Server Hypervisor Edition V6.1 on AIX
5655-N01 6.1.0 IBM WebSphere Application Server for z/OS

posted by Rohit Kelapure  # 8:58 AM 0 Comments

Thursday, September 6, 2012

 

Serviceability gem: WebSphere Application Server hung thread detection and recovery

Customers often ask me a question that goes like this 

Is there a way that hung threads could be manually or automatically killed to prevent the maxed out condition? For instance, once an alarm state is reached, could a script or a person look at the threads, identify "hung" threads, and kill them thus breaking the logjam? As I understand it, if a thread is hung then no data is being sent until the thread process completes. And if the thread dies then the request is simply re-sent by the originating application. So killing a thread will not actually hurt anything. Is this correct? And if so, how would we go about doing that? Trying think outside the box here. If we can't fix this, can we figure out a creative way to prevent it?

My response is as follows :  Yes there is a way out of the logjam. Prior to WebSphere Application Server 8.5 there are two ways to achieve what you are asking for ... 

1.  http://wasdynacache.blogspot.com/2012/03/websphere-application-server-jvm.html

Please read and comment.  Disadvantages of this approach are that tit aborts i.e. kills the JVM on the first hung thread which is abrasive since in-flight requests are killed.  Please note when you abort a JVM you may leave your system in an inconsistent state since in flight transactions and requests are terminated. 

2. Use a java client Thread_Hung event notification program that automatically monitor possibly hung threads and restarts the server via the nodeagent mbean http://www.ibm.com/developerworks/websphere/library/techarticles/0412_kochuba/0412_kochuba.html 

By default the hung thread detection threshold is 10 minutes (600 seconds). You may want to change that to 5 minutes . if you want a super responsive early warning system. Please note that you will need to set com.ibm.websphere.threadmonitor.false.alarm.threshold to 300. 

In WebSphere Application Server 8.5 and after you can use the Intelligent Management health monitoring and management subsystem  to monitor the application server environment and take action when certain criteria are discovered. see Configuring Health Management and Custom health condition subexpression builder

posted by Rohit Kelapure  # 8:53 AM 0 Comments

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