Workload management component troubleshooting tips

If the workload management component is not properly distributing the workload across servers in multi-node configuration, use the following options to isolate the problem.

Eliminate environment or configuration issues

Determine if the servers are capable of serving the applications for which they have been enabled. Identify the cluster that has the problem.
  • Are there network connection problems with the members of the cluster or the administrative servers, for example deployment manager or node agents?
    • If so, ping the machines to ensure that they are properly connected to the network.
  • Is there other activity on the machines where the servers are installed that is impacting the servers ability to service a request? For example, check the processor utilization as measured by the task manager, processor ID, or some other outside tool to see if:
    • It is not what is expected, or is erratic rather than constant.
    • It shows that a newly added, installed, or upgraded member of the cluster is not being utilized.
  • Are all of the application servers you started on each node running, or are some stopped?
  • Are the applications installed and operating?
  • If the problem relates to distributing workload across container-managed persistence (CMP) or bean-managed persistence (BMP) enterprise beans, have you configured the supporting JDBC providers and JDBC data source on each server?

If you are experiencing workload management problems related to HTTP requests, such as HTTP requests not being served by all members of the cluster, be aware that the HTTP plug-in balances the load across all servers that are defined in the PrimaryServers list if affinity has not been established. If you do not have a PrimaryServers list defined then the plug-in load balances across all servers that are defined in the cluster if affinity has not been established. If affinity has been established, the plug-in should go directly to that server for all requests.

For workload management problems relating to enterprise bean requests, such as enterprise bean requests not getting served by all members of a cluster:
  • Are the weights set to the allowed values?
    • For the cluster in question, log onto the administrative console and:
      1. Select Servers > Clusters.
      2. Select your cluster from the list.
      3. Select Cluster members.
      4. For each server in the cluster, click on server_name and note the assigned weight of the server.
    • Ensure that the weights are within the valid range of 0-20. If a server has a weight of 0, no requests are routed to it. Weights greater than 20 are treated as 0.

The remainder of this article deals with enterprise bean workload balancing only. For more help on diagnosing problems in distributing Web (HTTP) requests, view the "Web server plug-in troubleshooting tips" and "Web resource does not display" topics.

Browse log files for WLM errors and CORBA minor codes

If you still encounter problems with enterprise bean workload management, the next step is to check the activity log for entries that show:
  • A server that has been marked unusable more than once and remains unusable.
  • All servers in a cluster have been marked bad and remain unusable.
  • A Location Service Daemon (LSD) has been marked unusable more than once and remains unusable.

To do this, open the service log on the affected servers, and look for the following entries:

  • WWLM0061W: An error was encountered sending a request to cluster member member and that member has been marked unusable for future requests to the cluster cluster.
    Note: It is not unusual for a server to be marked unusable. The server may be tagged unusable for normal operational reasons, such as a ripple start being executed while there is still a load on the server from a client.
  • WWLM0062W: An error was encountered sending a request to cluster member member that member has been marked unusable, for future requests to the cluster cluster two or more times.
  • WWLM0063W: An error was encountered attempting to use the LSD LSD_name to resolve an object reference for the cluster cluster and has been marked unusable for future requests to that cluster.
  • WWLM0064W: Errors have been encountered attempting to send a request to all members in the cluster cluster and all of the members have been marked unusable for future requests that cluster.
  • WWLM0065W: An error was encountered attempting to update a cluster member server in cluster cluster, as it was not reachable from the deployment manager.
  • WWLM0067W: Client is signalled to retry a request. A server request could not be transparently retried by WLM because of exception:{0}

    In attempting to service a request, WLM encountered a condition that would not allow the request to be transparently resubmitted. The originating exception is being caught, and a new CORBA.TRANSIENT with minor code 0x49421042 (SERVER_SIGNAL_RETRY) is being thrown to the client.

If any of these warning are encountered, follow the user response given in the log. If, after following the user response, the warnings persist, look at any other errors and warnings in the Log Analyzer on the affected servers to look for:
  • A possible user response, such as changing a configuration setting.
  • Base class exceptions that might indicate a WebSphere Application Server defect.

You may also see exceptions with "CORBA" as part of the exception name, since WLM uses CORBA (Common Object Request Broker Architecture) to communicate between processes. Look for a statement in the exception stack specifying a "minor code". These codes denote the specific reason a CORBA call or response could not complete. WLM minor codes fall in range of 0x4921040 - 0x492104F. For an explanation of minor codes related to WLM, see the topic "Reference: Generated API documentation"for the package and class com.ibm.websphere.wlm.WsCorbaMinorCodes.

Resolve problem or contact IBM support

If the client logs indicate an error in WLM, collect the following information and contact IBM support.

  • A detailed description of your environment.
  • A description of the symptoms.
  • The server log files for all servers in the cluster.
  • A description of what the client is attempting to do, and a description of the client. For example, 1 thread, multiple threads, servlet, J2EE client, etc.

If none of these steps solves the problem, check to see if the problem has been identified and documented using the links in the "Diagnosing and fixing problems: Resources for learning" topic. If you do not see a problem that resembles yours, or if the information provided does not solve your problem, contact IBM support for further assistance.

If you do not find your problem listed there, contact IBM Support.




Related concepts
JDBC providers
Related tasks
Troubleshooting administration
Managing application servers
Modifying the default Web container configuration
Related reference
Installation problems
Data access problems
Web server plug-in troubleshooting tips
Web resource is not displayed
Reference topic    

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Last updated: Sep 20, 2010 10:03:57 PM CDT
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