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:
- Select .
- Select your cluster from the list.
- Select Cluster members.
- 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.
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.