When you mediate a service integration bus destination, your mediation
runs in a bus member (the "mediation execution point") and you specify
a combination of mediation points and queue points to handle the messages
that are mediated. When you interoperate with WebSphere MQ using WebSphere
MQ server, you can use one of several mediated exchange scenarios.
Queue-type destinations assigned to a WebSphere MQ server bus member can
be mediated in much the same way as destinations assigned to other bus members.
In addition to the mediation task described in Mediating a destination using a WebSphere MQ queue as the mediation point,
WebSphere MQ server supports other mediation scenarios that you also set up
using the administrative console Mediation wizard.
Note: Although WebSphere MQ server extends the way in which queue-type destinations
can be mediated, the way in which topic spaces are mediated does not change.
You need to understand the following terms:
- mediation point
- This is the location where messages are placed before they are mediated.
It can be either a service integration bus member (an application server or
a cluster) or a WebSphere MQ queue.
- queue point
- This is the location where messages are placed after they have been mediated.
It can be either a service integration bus member (an application server
or a cluster) or a WebSphere MQ queue. If there is a default forward routing
path and the destination is a queue-type destination, the queue point is unused.
If the destination is a service type destination, the queue point is absent.
- mediation execution point
- This is the server where the mediation process runs. If the mediation
point is a service integration bus member then the mediation execution point
is the same bus member as the mediation point.
For more information, see
WebSphere MQ queue points and mediation points.
WebSphere MQ server supports the following mediated exchange scenarios:
- Scenario 1: A WebSphere MQ mediation point and a service integration queue
point. In this case, you must specify the service integration bus member (a
server or cluster) where the mediation code runs. This bus member is called
the mediation execution point.
- Scenario 2: A WebSphere MQ mediation point and a WebSphere MQ queue point.
In this case, you can use a service integration mediation; you must specify
the mediation execution point when you configure the mediation, as for scenario
1.
- Scenario 3: A service integration mediation point and a WebSphere MQ queue
point. In this case, you do not need to specify the mediation execution point;
WebSphere Application Server automatically allocates the bus member where
the mediation point resides.
Alternatively (scenario 4) you can use a WebSphere MQ application or a
WebSphere Message Broker flow to mediate the destination. In this case, the
application or broker flow retrieves messages from the mediation point (which
is a WebSphere MQ queue), mediates the messages, then places the mediated
messages on the queue point (which is also a WebSphere MQ queue). You do not
specify a mediation execution point when you configure the mediation; instead,
you specify that there is an external mediation process.
Figure 1. Queue-type destinations assigned to a service integration bus
member.
Queue points and mediation points are queues of service
integration messages held in service integration
Figure 2. Queue-type destinations assigned to a WebSphere MQ server bus
member.
Queue points and mediation points can be queues of WebSphere
MQ messages held in WebSphere MQ. A WebSphere Message Broker, or other WebSphere
MQ application, can perform mediations externally.
The following table describes the mediated exchange scenarios in more detail:
Scenario |
How messages are processed |
Steps to complete in the Mediation wizard |
Scenario 1: Mediate a conventional queue-type destination
where the queue point is a service integration queue point, and assign a WebSphere
MQ queue as the mediation point (the input side of the destination).
As
the mediation point is a WebSphere MQ queue, a queue point must also be specified.
|
Messages arriving at the WebSphere MQ queue are processed
by the mediation running in an application server. When the messages have
been processed by the mediation, they are placed onto the service integration
queue point.
The mediation itself runs on a service integration bus
member nominated as the mediation execution point.
|
This example assumes that the destination is
assigned to a service integration bus member:
- Navigate to the destinations collection panel for the bus that hosts the
destination you want to mediate.
- Select the queue-type destination that you want to mediate, then click Mediate.
This starts the Mediate destination wizard:
- Step 1: select the mediation that you want to use to mediate the service
integration destination.
- Step 2: select a WebSphere MQ server bus member to host the mediation
point.
- Step 3: enter details of the WebSphere MQ queue that will be the mediation
point.
- Step 4: select a bus member where you want the mediation code to run.
- Step 5: review the summary of changes you are about to make, then click Finish.
|
Scenario 2: Mediate a WebSphere MQ queue type, with
a WebSphere MQ queue point, and assign a WebSphere MQ queue as the mediation
point (the input side of the destination).
As the mediation point is
a WebSphere MQ queue, a mediation execution point must also be specified.
|
Messages arriving at the destination are processed
by the mediation, then placed on the WebSphere MQ queue.
The mediation
itself will run on the service integration bus member nominated as the mediation
execution point.
|
This example assumes that the destination is
assigned to a WebSphere MQ server bus member:
- Navigate to the destinations collection panel for the bus that hosts the
destination you want to mediate.
- Select the queue-type destination that you want to mediate, then click Mediate.
This starts the Mediate destination wizard:
- Step 1: select the mediation that you want to use to mediate the service
integration destination.
- Step 2: select a WebSphere MQ server bus member to host the mediation
point.
- Step 3: enter details of the WebSphere MQ queue that will act as the mediation
point.
- Step 4: select the service integration bus member where you want the mediation
to run.
- Step 5: review the summary of changes you are about to make, then click Finish.
|
Scenario 3: Mediate a WebSphere MQ queue type and
assign a service integration mediation point.
|
Messages arriving at the destination are processed
by the mediation, then placed on the WebSphere MQ queue.
The mediation
code runs in the service integration bus member that is assigned as the mediation
point.
|
This example assumes that the destination is
assigned to a WebSphere MQ server bus member:
- Navigate to the destinations collection panel for the bus that hosts the
destination you want to mediate.
- Select the queue-type destination that you want to mediate, then click Mediate.
This starts the Mediate destination wizard:
- Step 1: select the mediation that you want to use to mediate the service
integration destination.
- Step 2: select the service integration bus member to host the mediation
point. The mediation code also runs in this bus member.
- Step 3: review the summary of changes you are about to make, then click Finish.
|
Scenario 4: Mediate a WebSphere MQ queue-type destination
and assign a WebSphere MQ queue as the mediation point (the input side of
the destination). The mediation of messages is performed by an external process.
|
Messages arriving at the WebSphere MQ queue are processed
by an external process, then placed by the external process on the WebSphere
MQ queue-type destination.
|
This example assumes that the destination is
assigned to a WebSphere MQ server bus member:
- Navigate to the destinations collection panel for the bus that hosts the
destination you want to mediate.
- Select the queue-type destination that you want to mediate, then click Mediate.
This starts the Mediate destination wizard.
- Step 1: select an external process to use for mediating the destination.
- Step 2: enter details of the WebSphere MQ queue that you want to act as
the mediation point.
- Step 3: review the summary of changes you are about to make, then click Finish.
|