For each SCA module deployed on WebSphere ESB,
requests being processed are held on queue points and in the data store for
messaging engines. You can display the data for SCA requests, and if appropriate
take further action to manage the throughput of SCA requests.
Why and when to perform this task
When an SCA module is running in WebSphere ESB,
requests normally flow through the enterprise service bus without
needing to be managed. Sometimes, you might want to check the throughput of
a request, check the contents of a request, or if some problem has occurred
delete a request. You might also want to take other actions such as to monitor
the overall throughput of requests, or change the reliability setting for
requests.
Requests are handled as messages by the service integration technologies of
the underlying WebSphere Application Server.
For this reason, actions to manage requests are managed by using the WebSphere Application Server tasks
to act on service integration messages.
This topic provides an overview
of the main tasks that you might consider using, and links into the WebSphere Application Server tasks
for more detailed information.
Alternatives for this task
- Listing messages on a message point
SCA requests that are being processed are held on queue points of
the SCA.SYSTEM.cell_name.Bus. You can list the SCA requests
either through a queue destination for a component of the SCA module, or through
the messaging engine that hosts a queue point; for example:
- Resolving locked messages on a message
point
If a problem occurs, an SCA request might remain
locked on the queue point where it is being processed. You can display the
message State property that indicates whether or not
the request is locked, and if appropriate take further action to resolve the
problem.
- Deleting messages on a message point
Under exceptional circumstances, you might need to delete one or
messages that exist on a message point for a selected bus destination or messaging
engine. You should not normally need to delete messages on a message point.
This task is intended as part of a troubleshooting procedure.
- Viewing data in the data store for
a messaging engine.
A messaging engine maintains requests
as volatile (nonpersistent) and durable (persistent) data in its data store.
You
can use the database tools for the data store to view request data in the
data store for a messaging engine. For example, if the messaging engine uses
the default Cloudscape database, you can use the CloudView tool to view request
data.
- Changing message reliability
for a destination
Request messages have a quality of
service attribute that specifies the reliability of message delivery. You
can select a reliability to suit your requirements for assured delivery, and
system performance. The administrator can specify the reliability setting
on bus destinations, or the reliability can be specified by individual producers
(typically under application control through an API call).