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, William Wentworth, Joseph Lam
Co-authored by: Shawfu Chen and Steve Dittmar
As of IBM WebSphere Application Server V8.5, users on most platforms can choose to run on Java SDK 6.1 or 7.0, with support for 7.1 having been added more recently. Java SDK 6.1 continues to be shipped with, and updated automatically by, the WebSphere Application Server fix packs. However, some users do not realize that Java SDK 7.x fix packs are not included in the WebSphere Application Server fix packs and thus is not automatically installed or kept up-to-date by the... [More]
Sometimes servers do not start. Maybe it is due to a bad build, the configuration has gotten corrupted, or it just stopped working. This blog helps you understand the anatomy of the Application Server start up process. It provides you with troubleshooting and debugging techniques to determine why the server is not starting or why the server is not stopping.
Starting the server
Let's see what happens when a server is started using the startServer.sh /bat server1 command.
Two Java virtual machines... [More]
This 2-part blog is focused on some commonly occurring exceptions for the status cache problem. With this problem, the status display of an application server, node agent, or an application is shown as 'red' or 'unknown' on the WebSphere Administrative Console. However, the actual process is up running.
In part 1, we will look at when this type of issue can occur due to one of the following areas:
Discovery ports with firewall
Operating system level
This blog is part 2 of a 2-part blog that is focused on some commonly occurring exceptions for the status cache problem. To read part 1 first, see Common status cache problems in the WebSphere Administrative Console - Part 1 .
With this problem, the status display of an application server, node agent, or an application is shown as 'red' or 'unknown' on the WebSphere Administrative Console. However, the actual process is up running.
In part 2, we will look at when this type of issue can occur due... [More]
Windows Authentication is not a WebSphere Application Server feature . Instead it is a capability provided by the Windows operating system and the MS JDBC Driver should be supporting it. All that needs to be done in WebSphere Application Server (WAS) is to not define a J2C Authentication alias and configure the data source custom property integratedSecurity=true .
Add the .dll files for the driver to the WebSphere Application Server Installation. The .dll files can be obtained with a SQL Server driver from Microsoft. The... [More]
WebSphere Application Server uses multiple temporary locations for many reasons. This blog explains the most commonly used temporary files, why they are used and when they can be removed. This blog will also explain the files and directories that can be removed under the profile direction with caution.
Be careful in deleting any temporary, cache and log files in WebSphere Application Server!
Before making any changes to the environment , take a backup of the... [More]
A wealth of valuable JVM diagnostic data can be gathered by doing the following tasks:
Generate a Java™ thread dump.
Enable logging of verbose garbage collection data for Server.
Generate a Java heap dump.
Generate a system core dump & snap trc file.
In the overall process of problem determination, diagnostic data must be collected or generated, and the data must be analyzed. Various tools are available to help you analyze diagnostic data for solving problems. Below... [More]
Here are the most commonly asked questions about running IBM WebSphere Application Server as a non-root user. Its applicable for a WebSphere Application Server V6.0 profile and later.
It is a common practice to run the application server as a non-root user. Most of the WebSphere Application Server users install and run the application server as a non-root user only. There are no restrictions on how you protect your resource. You can set the permission of the file as you like, but there are some key and... [More]
This blog contains some common questions and answers that are related to the use of JMS connection pools and session pools. Hopefully this information will help you in your environment tuning efforts.
Q: WebSphere MQ Queue Connection Factories in WebSphere Application Server releases contain both a connection pool and a session pool for configuration. When configuring the session pool, is this configuration for each connection? For example, if my connection pool has a maximum size of 10, and my session pool also has a... [More]
In one of Vish's blogs, he explains how to install the optional Java 7.x on WebSphere Application Sever 8.5:
Installing optional Java 7.x on WebSphere Application Server 8.5
Once it is installed, however how can you tell which version of Java is actually being used? You can look at the SystemOut.log header, but the output may be a little... [More]
Configuration migration is the process of upgrading a WebSphere Application Server installation to a newer major release. Migration leverages the existing configuration and applications and migrates them to the newest version environment. This blog provides important tips when you are running Migration Utilities ( Configuration Migration Tool (CMT) or command line (WASPreupgrade/WASPostupgrade)) to migrate WebSphere Application Server from one version to another.
Make sure that the ulimit for open files is not set to the... [More]
Shared resource Directory
The shared resources directory is the directory where installation artifacts are located, which can be used by one or more package groups. The Shared Resources Directory acts as a cache of data to local and web repositories. It contains files that can be shared by multiple packages and product installations.
The location of this directory can only be selected the first time you install a package with the IBM Installation Manager (IM). For example,... [More]
Rolling back or uninstalling a fix pack involves moving from a newer release of a fix pack to a previous release of a fix pack.
We always specify the version we want to rollback to (not the currently installed). I will provide details on this rollback command and a sample usage scenario for you.
./imcl rollback offering_ID_offering_version -installationDirectory installation_directory -acceptLicense -sP
The offering_ID is the... [More]
Starting with IBM WebSphere Application Server (WAS) v184.108.40.206, you can install Java 7.0 as an optional feature. WAS v220.127.116.11 comes with Java 6 as the default Java SDK. Java 7.0 can be added at any point in time to the installation, thereby adding the Java 7.0 SDK selection to the possible choices of Java SDKs that can be used. For completeness:
Java 7.0 was shipped as an optional feature that can be installed with WAS v18.104.22.168
Java 7.1 is shipped with WAS v22.214.171.124 (in a full... [More]
At IBM we are always looking for new ways to enhance your Support experience. If you are a client of IBM WebSphere Application Server on distributed platforms or IBM WebSphere MQ on distributed or z/OS in the USA you now have the opportunity to interact with us in a whole new way - Technical Support Chat .
With Technical Support Chat you can discuss your request and communicate one-on-one with an experienced Level 2 Support Engineer. And because we know that every Service Request is unique, at any time during the... [More]
Upon investigation of a WebSphere Application Server performance issue, you may find that the poor performance correlates with long classloader unload times. To check if this is indeed a problem, enable verbose GC and note the times of poor performance. Then correlate the times of poor performance to the time stamps in the verbose GC data:
Example of long class unload time as seen in the verbose GC output (default log is the native_stderr.log in WebSphere):
This time around, I have a requirement to deploy IBM HTTP Server (IHS) and the WebSphere Plugin to route traffic to WebSphere Application Server (WAS). So far, so good. However, the difference is that, this time, I'm NOT leveraging the power of WAS Network Deployment ( WAS ND ). There are no clusters here. Equally, the two instances of WAS are completely self-contained. For my proof of concept, I've got a single set of WAS binaries ( I am using WAS 126.96.36.199 ) with a pair of standard profiles, AppSrv01 and AppSrv02.... [More]
High Availability (HA) Manager is a framework that allows singleton services to make themselves highly available. Transaction Log Recovery is one of the HA Manager users.
Every WebSphere Application Server process is a member of a HA Manager DCS CoreGroup. During server (cluster member) startup, transaction manager and other server components will also get started. Transaction Manager should have exclusive ownership of its transaction recovery log file before it can initialize successfully. HA... [More]
The following list consists of the top ten best practices compiled from numerous common problems that I have seen throughout my technical support years. Most of these issues could easily be prevented by taking these simple precaution steps. So, if you're a WebSphere administrator, this is your must-read !
If you're on Linux or UNIX environment, make sure the ulimit value for no-files/open files or file descriptors is 10,000 or higher . This is the recommended value for migration tasks, application... [More]