TMF Operations and Recovery Guide (G06.24+)

Routine Maintenance

HP NonStop TMF Operations and Recovery Guide—522417-002

2-23

What Happens When a Link is Restored

When a communications link is restored, the normal sequence of events for

homogeneous distributed transactions resumes where it was interrupted. The TMPs

that had lost touch with one another reestablish communication, and exchange

information about distributed transactions that were in progress.

If the link failure occurs when the transaction is in the active state in the parent node

and in the prepared state in a child node, the transaction is automatically aborted in the

parent node. When the link is restored, the child-node TMP finds out that the

transaction was aborted in the parent node, and therefore aborts the transaction in the

child node (maintaining consistency between the two nodes).

If communications cannot be reestablished, you might need to resolve incomplete

transactions. See Controlling Individual Transactions on page 3-20 for more

information.

Displaying Status of Distributed Transactions

The STATUS TRANSACTIONS command displays information about transactions of

all types, including homogeneous and heterogeneous distributed transactions. If you

enter this command without the DETAIL option and a transaction has a resource

manager as either a parent or a child, the Parent and/or Children columns in the

display will show the notation “Foreign” for each transaction branch. If a

heterogeneous transaction has been exported multiple times by different resource

managers or by the same resource manager, the entry “Foreign” will appear for each

exported branch in the Children column.

An example of a STATUS TRANSACTIONS display showing heterogeneous

transactions follows:

TMF 40> STATUS TRANSACTIONS

Transaction Identifier Process State Parent Children

-------------------------- ---------- --------- -------- ----------

\TSII.4.90273 active Foreign

\SVLDEV.3.39485 prepared \SLVDEV

Foreign

\PRUNE.5.2343 prepared \PRUNE

Foreign

\TSII.3.93283 $APPL3 committed

Foreign

If you enter a STATUS TRANSACTIONS command with the DETAIL option and

heterogeneous transactions are present on the system, the actual names of the foreign

resource managers appear in the Parent and/or Child rows. In this case, the resource

manager name is followed by a period and then the transaction branch number: for

example, TUX-HP@ESSG.1. The branch number helps distinguish between two

separate exports of the same transaction from the same resource manager.