IBM SC33-1683-02 Server User Manual


 
When the distributed routing program is invoked
For BTS processes and activities started by RUN ASYNCHRONOUS commands,
CICS invokes the distributed routing program at the following points:
On the requesting region:
1. Either of the following:
v For routing the activity. This occurs when the transaction associated with
the activity is defined as DYNAMIC(YES).
v For notification of a statically-routed request. This occurs when the
transaction associated with the activity is defined as DYNAMIC(NO). The
routing program is not able to route the activity. It could, however, do
other things.
2. If an error occurs in route selection—for example, if the target region
returned by the routing program on the route selection call is unavailable.
This gives the routing program the opportunity to specify an alternate target.
This process iterates until the routing program selects a target that is
available or sets a non-zero return code.
3. After CICS has tried (successfully or unsuccessfully) to route the activity to
the target region.
This invocation signals that (unless the requesting region and the target
region are one and the same) the requesting region’s responsibility for this
transaction has been discharged. The routing program might, for example,
use this invocation to release any resources that it has acquired on behalf
of the transaction.
On the target region:
These invocations occur only if the routing program on the requesting region
has specified that it should be reinvoked on the target region
:
1. When the activation starts on the target region (that is, when the transaction
that implements the activity starts).
2. If the routed activation (transaction) ends successfully.
3. If the routed activation (transaction) abends.
Figure 46 shows the points at which the distributed routing program is invoked, and
the region on which each invocation occurs. Note that the “target region” is not
necessarily remote—it could be the local (requesting) region, if the routing program
chooses to run the activity locally.
Route selection
Notification
Route selection error
Routing attempt complete
Requesting region
Transaction initiation
Transaction termination
Transaction abend
Target region
Figure 46. When and where the distributed routing program is invoked
routing BTS activities
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CICS TS for OS/390: CICS Customization Guide
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