Commit mode and sync level processing
The commit mode that you choose determines the type of commit mode processing that IMS™ performs.
The Java™ client
specifies the commit mode protocol
that is used when it submits a transaction request to IMS. IMS Connect
and IMS support two types of commit mode processing:
- Commit mode 0 (commit-then-send), where IMS commits the IMS database changes and then sends the output to the client
- Commit mode 1 (send-then-commit), where IMS sends the output to the client and then commits the database changes
Associated with the commit mode protocols, IMS Connect
and IMS also support three synchronization levels
(sync levels): NONE, CONFIRM, and SYNCPT (the sync-point protocol).
All three sync levels can be used with commit mode 1. Only CONFIRM
can be used with commit mode 0. The Java client
cannot explicitly set the sync level to SYNCPT. The IMS TM resource
adapter supports
only the following combinations:
Commit mode | Sync level = NONE supported | Sync level = CONFIRM supported |
---|---|---|
commit mode 0 | No | Yes |
commit mode 1 | Yes | Yes |
Commit mode 1 with sync level SYNCPT is used by the IMS TM resource adapter when it participates in two-phase commit processing with IMS.