Technical support knowledge for Application Integration Middleware including WebSphere, CICS, BPM, MQ, Broker, IIB, ODM, DataPower, Mobile, Appliances, and more! Following the IBM Social Computing Guidelines - Steve Webb, Joseph Lam
With an increasing amount of stack products being available and used with WebSphere Application Server on z/OS, we're starting to see EC3 timeouts of different varieties that are caused by Mbean long waits or deadlocks. An initial review of the dump and reason code may produce what looks like a common timeout, like HTTP or EJB. But closer inspection of an SVC dump or javacore could reveal that the thread that took the timeout was actually waiting on an internal Mbean request.
In general, Mbean requests flow... [More]
The WebSphere L2 Support team handles its fair share of WebSphere Application Server performance analysis. Often it appears as though the Monitoring Agent (that thing that reports whether the system is behaving - or not) is the problem itself. The truth is, the more problems that the agent has to report, the more noise the agent is going to interject into the diagnostic data. It's a vicious cycle.
One of the common agents that are encountered is Wily. Like any performance monitoring tool, Wily can introduce a... [More]
List of firewall ports that must be open for communication between the deployment manager, nodeagent, and Application Server
It's very important to know the ports that should be opened in the firewall for proper communication between deployment manager, nodeagent, and application servers. Follow the below steps to achieve this task.
Find the port numbers in the serverindex.xml file or from the ISC (Integrated Solution Console)
The serverindex.xml file can be found under the... [More]
Occasionally when reviewing a heapdump that was generated from an out of memory event, the largest consumer of heap memory may consume slightly more memory than the other objects. Because of this, WebSphere users and moderators may incorrectly accuse the largest heap consumer as a memory leak.
If a Java™ heap is sized too small, an out of memory error will occur regardless if a memory leak exists. The leak suspect shown in IBM HeapAnalyzer or Memory Analyzer (MAT) will show a java object... [More]
The transaction timeout value can be set in the application component or in the administrative console for WebSphere Application Server (WAS). If the application component does not specifically set its own transaction timeout, WAS will timeout a transaction according to the 'Total transaction lifetime timeout' property. This property is the default maximum time allotted for a transaction to complete before it is timed out. If completion processing is not started on the transaction before this timeout value is reached, it... [More]
If there is no cell default certificate SSL setting, then JSSE will pick one.
To set a default do the following:
In your Deployment Manager environment, logon to the Admin console.
Go to Security --> SSL certificates and key management --> manage endpoint security configurations.
Under inbound, select the entry that contains your cell name followed by "(CellDefaultSSLSettings,)".
Next click on update certificate alias list under SSL configuration.
The common question
I've been asked multiple times through various means, "How can I tell if my iFix is installable as-is when I upgrade WebSphere Application Server (WAS) to a newer fix pack level?" The answer, as it is to so many things, is "it depends." The manual method is not necessarily difficult, but may be a bit tedious if you have a lot of iFixes to consider. The automatic method is sometimes simpler and can be performed through the Installation Manager (IM) GUI or command line tool, depending... [More]
When WebSphere Application Server is running a transaction, the transaction information is written to the tranlog directory to log1 & log2. The resources required for that transaction (database name, user, password, etc) are recorded in the partnerlog directory to it's log1 & log2. When a transaction completes, the transaction information is garbage collected from the logs. If the application server should abend or be forced off mid-transaction, such that a transaction does not complete, then on subsequent server... [More]
We've probably all see a hung JVM at one time or another and chances are you've figured this out in one of two was if you're dealing with WebSphere Application Server: 1. the users are complaining that the browser just “spins” and never returns a web page, or 2. you've noticed output in the WebSphere logs (SystemOut.log) that indicate potentially hung threads. For the purposes of this discussion, we'll focus on the latter method.
WebSphere Application Server provides a feature that... [More]
Staying abreast of issues deserving heightened awareness in WebSphere Application Server on z/OS
WebSphere Application Server for z/OS (zWAS) has always behaved and been administered a little differently from most other products on z/OS. On top of that, when we released zWAS Version 8 we deviated further with the move from SMP/E to Installation Manager (IM) for installation and maintenance. Along the way we have also had to evolve the manner in which we document some of the issues that deserve heightened awareness (like... [More]
The default behavior for DirectByteBuffer is that 64 MB of memory is reserved at startup for direct byte buffers. The buffers are then allocated out of the reserved space. If a request for a buffer is made, and there is not sufficient space to satisfy the allocation, then a call to system.gc is made in order to free up any buffers that are no longer in use. If, after the system gc, there is still insufficient memory to satisfy the allocation, then the reserved space is expanded by 32Mb.
This behavior can be... [More]
Since WebSphere is such a vast product mix and comes in many versions with varying components and different complexity, it is sometimes difficult to find the exact content you are searching for when browsing the IBM Knowledge Center. A typical search will likely bring back the correct topic but for the wrong version or component.
However, taking what we have learned to narrow down searches in a web browser, we can apply the same parameters in the IBM Knowledge Center search feature.
Google Search Operators - Google... [More]
Perhaps you've run into this scenario: The Windows Service states the JVM process is started but WebSphere Application Server does not start. The SystemOut.log shows no entries in the log, the startServer.log shows that the JVM is waiting on initialization indefinitely. Windows task manager may show that a Java™ process is consuming high CPU but the Process ID (PID) does not match any of the server PIDs.
To check if the Windows Service is the problem:
Make sure that all the java processes are... [More]
Where do I start with sizing the heap for my WebSphere Application Server? This question is very common when trying to determine where to begin sizing your heap for your application when using WebSphere Application Server. The default heap sizes are for use during installation and are often way too small for use in production environments. The first place to begin is to know if the server has 32-bit or 64-bit architecture and whether your installation of WebSphere Application Server is a 32-bit or 64-bit environment. Next determine... [More]
If you run WebSphere Application Server on z/OS you are aware of the many 'timer' settings that can affect the workload that is running in the Server.
This Blog entry will focus on the topic of dispatch timeout handling, and the tradeoffs between settings that control the behavior of the environment when dispatch timeouts occur.
Let's first look at the Dispatch Process Overview in the WebSphere Application Server on z/OS.
1. Request Received... [More]