Known issues

• Process auto-discovery of !WebSphere instances may fail on Windows. This has been observed with RHQ 3.0.0, Windows XP and WebSphere 8.0, but is likely to occur with other versions. The issue is caused by the fact that the !WebSphere process has a long list of command line arguments and that this list is truncated by RHQ (or by the [SIGAR](http://www.hyperic.com/products/sigar SIGAR) library used by RHQ).
• On RHQ versions before 4.5, if a single agent is used to monitor a large number of !WebSphere instances, the plug-in may fail to collect all metrics. One of the symptoms of the issue is that the Late Collections per Minute metric on the Agent Measurement Subsystem resource constantly remains at a non zero value. The problem is caused by a flaw in RHQ. See BZ 834019.
• The agent auto-update feature doesn't work well with the RHQ WebSphere plug-in because part of the configuration is lost during auto-update. To work around the issue, update the agent(s) manually using the following procedure:
  1. Stop the RHQ agent.
  2. Launch the agent installer using java -jar ~/rhq-agent-x.y.z.jar --update --launch false.
  3. The update preserves the changes in bin/rhq-agent-env.sh, but neither the JAR files added to the class path nor the conf/commons-logging.properties file. Therefore you need to reexecute the relevant steps described in the [SetupGuide setup guide] (or copy the relevant files from the agent backup created by the installer).
  4. The persistent state of the plug-in is lost during the update, as described in BZ 863346. Therefore you need to restore it from the backup of the old RHQ agent, e.g. using cp -a rhq-agent-OLD/data/WebSphere rhq-agent/data.
  5. Start the agent.
• (Issue #12) The RHQ WebSphere plug-in allows to change the maxConnections property of a JDBC data source at runtime. This is particularly handy during certain types of incidents. However, after the value is changed, there may be a noticeable performance degradation of the !WebSphere server. The issue persists even after the maxConnections property has been reset, and a restart of the server is necessary to restore normal performance.
• The RHQ WebSphere plug-in is affected by class loader leaks caused by issues in the IBM libraries. Note that this is the case regardless of whether the IBM libraries are added to the class path of the agent or loaded by the plug-in class loader. This implies that it is generally not safe to restart the plug-in without restarting the JVM of the agent, i.e. it is not safe to use the Restart Agent and Restart Plugin Container operations defined by the RHQ Agent resource. Instead, use the Restart operation defined by the RHQ Agent Launcher Script resource or restart the agent manually from the command line.