About this task
You can use
WebSphere® MQ resources in either local or globally
coordinated transactions:
- For local transactions, you can have multiple queue managers participating in a message flow.
Connections to queue managers can be local, client, or both. On z/OS®, you can use local connections only.
- For globally coordinated transactions on distributed systems, you must specify a local queue
manager on the integration node. This queue manager is the global transaction manager, and no other
WebSphere MQ resources can be used in the message flow. On z/OS, all queue managers are globally coordinated. For more information
about configuring for globally coordinated transactions, see Configuring global coordination of transactions (two-phase commit).
If the connection is lost to the queue manager that was specified on the integration node
in a globally-coordinated transaction, the integration node enters a standby state until the queue
manager becomes available again. If the integration node was configured by using an MQ Service, then
the integration node is stopped.
If
a connection to a queue manager is lost, and that connection is enlisted
in a transaction, automatic reconnection is delayed until the inflight
transaction is complete. Other queue managers that are required, but
are not part of the transaction, reconnect automatically without delay.
A completed transaction can include the following cases:
- The unavailable MQ resource was not required and was not used,
because exception handling was defined in the message flow, so the
inflight transaction was successful and committed.
- The unavailable MQ resource was required, and the message flow
cannot succeed without it, so the inflight transaction was rolled
back.
Review how to set the properties
for MQ nodes to determine how they participate in transactions.