Workload is not getting distributed

 

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1. General Troubleshooting
2. HTTP requests are not distributed to all servers
3. Enterprise bean requests are not distributed to all servers
4. Enterprise bean requests are not distributed evenly
5. A failing server still receives enterprise bean requests (failover is not completed)
6. Stopped or hung servers do not share the workload after being restored
7. A cluster does not fail over to its backup cluster

 

General Troubleshooting

1. Browse the JVM logs of the problem deployment manager and appservers:

2. Use the Log and Trace Analyzer tool to browse and analyze the service log (activity.log) of the deployment manager and any nodes encountering problems. View the activity.log files...
   app_server_root/logs

   If Java exceptions appear in the log files, try to determine the actual subcomponent that is directly involved in the problem by examining the trace stack and looking for a WAS-related class near the top of the stack...

   
   com.ibm.websphere.*
   com.ibm.ws

3. Ensure that all the machines in the configuration have TCP/IP connectivity to each other by running the ping command:
   1. From each physical server to the deployment manager
   2. From the deployment manager to each physical server

4. If your topology consists of a Windows-based deployment manager with supported UNIX systems servers, browse any recently-updated .xml and .policy files on the supported UNIX systems using vi to ensure that Control-M characters are not present in the files. To avoid this problem in the future, edit these files using vi on the supported UNIX systems, to avoid inserting these characters.

 

HTTP requests are not distributed to all servers

If HTTP requests are not being distributed to all servers:

• Check your Primary Servers list.

  The plug-in load balances across all servers that are defined in the Primary Servers list, if affinity has not been established. If you do not have a Primary Servers list defined, the plug-in load balances across all servers defined in the cluster, if affinity has not been established. In the case where affinity has been established, the plug-in should go directly to that server, for all requests within the same HTTP session.

• If some servers are servicing requests and one or more others are not, try accessing a problem server directly to verify that it works, apart from workload management issues. If that does not work:

  • Use the console to ensure that the affected server is running.

  • See the topic "Web resource does not display" for more information.

• See the "HTTP plug-in component troubleshooting tips" topic for more information.

• Check the steps for diagnosing workload management issues in the "Troubleshooting the Workload Management component" topic.

 

Enterprise bean requests are not distributed to all servers

If a client cannot reach a server in a cluster thought to be reachable, a server might be marked unusable, or is down. To verify this:

• Use the console to verify that the server is started. Try starting it, or if started, stop and restart it.

• Browse the console and verify that the node that runs the server having the problem appears. If it does not:

  • Review the steps for adding a node to a cluster.

  • Review the steps in the section One or more nodes do not show up in the console.

• If possible, try accessing the enterprise bean directly on the problem server to see if there is a problem with TCP/IP connectivity, appserver health, or other problem not related to workload management. If this fails, review the "Cannot access enterprise bean from a servlet, JSP, stand-alone program , or other client" topic.

• Check the steps for diagnosing workload management issues.

 

Enterprise bean requests are not distributed evenly

There are a number of possible reasons for this behavior, which generally fall into one or more of these categories:

• Improper configuration

• Environment issues such as the availability of servers or applications.

• A large numbers of requests that involve transactional affinity, or

• A small number of clients

Workload management in WAS is based on a weighted proportional scheme to spray requests among the servers. This results in balance being determined by numbers of requests rather than by any other measure. A true balance problem is determined by comparing the number of requests processed by each member of the cluster with the weights set for each of those members. This is done by following the steps in the topic "Troubleshooting the Workload Management component".

• When the percentage of requests that arrive for each member of the cluster is consistent with the weights then further analysis of the application is required to determine the cause for the workload being imbalanced even when the number of requests is balanced.

• When the number of numIncomingNonWLMObjectRequests is not balanced among the members of the cluster and is large in relation to the numIncomingRequests then the reason for the imbalance is the non-distributable components installed on the members of the cluster. A modification to the configuration will yield a more balanced environment.

• When the number of numIncomingStrongAffinityRequests is not balanced among the members of the cluster and is large in relation to the numIncomingRequests then the reason for the imbalance is the requests which are invoked within a transaction. These can be reduced by installing the objects involved within a transaction within the same cluster.

 

A failing server still receives enterprise bean requests (failover is not completed)

Some possible causes of this problem are:

• The client might have been in a transaction with an enterprise bean on the server that went down. Check the JVM logs of the appserver hosting the problem enterprise bean instance. If a request is returned with CORBA SystemException COMM_FAILURE org.omg.CORBA.completion_status.COMPLETED_MAYBE, this might be working as designed. The design is to let this particular exception flow back to the client, since the transaction might have completed. Failing over this request to another server could result in this request being serviced twice.

• If the requests sent to the servers come back to the client with any other exceptions consistently, it might be that no servers are available. In this case, follow the resolution steps as outlined in the topic "Troubleshooting the Workload Management component".

 

Stopped or hung servers do not share the workload after being restored

This error occurs when the servers that were unavailable are not recognized by the Workload Management component after they are restored. There is an unusable interval determined by the property com.ibm.websphere.wlm.unusable.interval during which the workload manager waits to send to a server that has been marked unusable. By default this is 5 minutes.

You can confirm that this is the problem by ensuring that servers that were down are now up and capable of servicing requests. Then wait for the unusable interval to elapse before checking to determine whether failover occurs.

 

A cluster does not fail over to its backup cluster

You might experience an error that is similar to the following sample:

[10/11/04 13:11:10:233 CDT] 00000036 SelectionMana A WWLM0061W: An error was encountered sending a request to cluster member {MEMBERNAME=FlorenceEJBServer1, NODENAME=fwwsaix1Node01} and that member has been marked unusable for future requests to the cluster "", because of exception: org.omg.CORBA.COMM_FAILURE: CONNECT_FAILURE_ON_SSL_CLIENT_SOCKET - JSSL0130E: java.io.IOException: Signals that an I/O exception of some sort has occurred. Reason: Connection refused vmcid: 0x49421000 minor code: 70 completed: No"

Perform the following steps to fix the configuration:

1. Review your deployment manager hostname and bootstrap port for each backup cluster setting.

2. Review your core group bridge peer ports to make sure the hostname and distribution and consistency services (DCS) port are accurate.

3. Verify that the names of your primary and backup clusters match.

4. If your application is going through security to go to the backup cluster, review your security configuration. You might need to use single sign on (SSO) and import the LTPA keys to the backup cell.

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

For current information available from IBM Support on known problems and their resolution, see the IBM Support page. You should also refer to this page before opening a PMR because it contains documents that can save you time gathering information needed to resolve a problem.

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Related tasks

Troubleshooting administration
View JVM logs
Adding logging and tracing to your application

 

Related Reference

Multiserver environment errors
Workload management component troubleshooting tips
Naming service troubleshooting tips
Application access problems
Enterprise bean cannot be accessed from a servlet, a JSP file, a stand-alone program, or another client
Application client sending SOAP request receives errors
Web module or appserver stops processing requests
Application deployment problems
Web server plug-in troubleshooting tips
Web resource is not displayed
Access problems after enabling security