This information might help you diagnose the trouble if
you are having a workload distribution problem.
New feature: This topic
references one or more of the application server log files. Beginning
in WebSphere Application Server Version 8.0 you can configure the
server to use the High Performance Extensible Logging (HPEL) log and
trace infrastructure instead of using
SystemOut.log ,
SystemErr.log,
trace.log, and
activity.log files or native z/OS logging
facilities. If you are using HPEL, you can access all of your log
and trace information using the LogViewer command-line tool from your
server profile bin directory. See the information about using HPEL
to troubleshoot applications for more information on using HPEL.
newfeat
What kind of problem are you seeing?
If none of these problem solution descriptions fix your problem:
- Browse the JVM logs of the problem deployment manager
and application servers:
- Look up any error messages by selecting the Reference view
of the information center navigation and expanding Messages in
the navigation tree.
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 product-related
class near the top of the stack (names beginning with com.ibm.websphere or com.ibm.ws)
that created the exception. If appropriate, review the steps for troubleshooting
the appropriate subcomponent under the Troubleshooting WebSphere
applications section of the Information Center.
For example,
if the exception appears to have been thrown by a class in the com.ibm.websphere.naming
package, review the Naming Services Component troubleshooting tips
topic.
- Ensure that all the machines in your configuration have TCP/IP
connectivity to each other by running the ping command:
- From each physical server to the deployment manager
- From the deployment manager to each physical server
- Although the problem is happening in a clustered environment,
the actual cause might be only indirectly related, or unrelated, to
clustering. Investigate all relevant possibilities:
- If an enterprise bean on one or more servers is not serving requests,
review the "Cannot access an enterprise bean from a servlet, JSP,
stand-alone program, or other client" and "Cannot look up an object
hosted by the product from a servlet, JSP file, or other client" topics.
- If problems seem to appear after enabling security, review the
"Errors or access problems after enabling security" topic.
- If an application server stops responding to requests, or spontaneously
dies (its process closes), review the "Web module or application server
dies or hangs" topic.
- If SOAP requests are not being served by some or all servers,
review the "Errors returned to client trying to send a SOAP request"
topic.
- Check to see if the problem is identified and documented by looking
at available online support (hints and tips, technotes, and fixes).
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 administrative 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.
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 administrative console to verify that the server is started.
Try starting it, or if started, stop and restart it.
- Browse the administrative 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 administrative console.
- If possible, try accessing the enterprise bean directly on the
problem server to see if there is a problem with TCP/IP connectivity,
application server 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.
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 application server 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.
Stopped or hung servers do
not share the workload after being restored
This error occurs
when previously unavailable servers are not recognized by the workload
management component after those servers 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.