Review the following topics if you encounter a problem with your high availability environment.
In a properly set up high availability environment, a high availability manager can reassess the environment it is managing and accept new components as they are added to the environment. For example, when a Java virtual machine (server) is added to the infrastructure, a discovery process begins. During startup the server tries to contact the other members of the core group. When it finds another running server, it initiates a join process with that server that determines whether or not the server can join the core group. If the new server is accepted as a member of the core group, all of the servers, including the new one, log message HMGR0218I . This message is also displayed on the administrative console.
Message HMGR0218I indicates the number of application servers in the core group that are currently online. If this message is not displayed after a server starts, either a configuration problem or a communication problem has occurred. To fix this situation, verify that the application server is running on a current configuration, by either using the deployment manager to tell the node agent to synchronize, or use the syncNode command to manually perform the synchronization. If the server still cannot join the core group, a network configuration problem exists.
Message HMGR0123I might appear in the system log file if the status of core group members changes at the same time as the active coordinator changes. For example, this message might be issued when a core group member restarts and becomes the active coordinator.
This information message usually does not indicate a serious problem. Even if this message appears in the system log file, the new active coordinator receives the updated group status. If you want to minimize the occurrences of this message, you should select a core group member that does not frequently restart as the preferred core group coordinator.
CPU starvation detected error messages are displayed in the system log file whenever there is not enough physical memory available to allow the high availability manager threads to have consistent runtimes. When the CPU is spending the majority of its time trying to load swapped-out processes while processing incoming work, thread starvation might occur. The high availability manager detects this condition, and logs these error messages informing you that threads are not getting the required runtime.
To achieve good performance and avoid receiving these error messages, IBM recommends that you allocate at least 512 MB of RAM for each Java process running on a single machine.
To decrease the CPU time spent in discovery: