TMF Introduction (G06.26+)

Transaction Coordination
HP NonStop TMF Introduction—522414-002
2-5
How Distributed Transaction Coordination Works
The transaction management process (TMP) on each participating node records the
parent nodes and child nodes for each transaction.
A transaction branch refers to that part of a distributed transaction being processed by
one resource manager or transaction manager.
Coordination of Child Transactions
For child, or outgoing, transactions, TMF treats the gateway as a surrogate resource
manager; the gateway manages the remote resource. TMF does not directly
communicate with the remote transaction manager or resource manager. The local
transaction manager views the gateway as a resource manager; the remote system
views the gateway as a transaction manager.
Coordination of Parent Transactions
For parent, or incoming transactions, TMF acts as a subordinate transaction manager;
it commits or aborts the transaction branch as directed by the superior transaction
manager. In this situation, TMF is the local commit coordinator.
Figure 2-3. Commit Coordinator and Subordinate Transaction Managers
Subordinate TM
Subordinate TM
VST053.vsd
Commit
Coordinator