Use this task to identify and resolve locked messages, which are
messages that are currently unavailable to a message consumer or browser accessing
a message point.
About this task
Under
normal circumstances, a message is locked for a relatively short period by
another messaging application and is either then removed or made available
to the message point (that
is, unlocked). However, there are a number of ways in which a message can
remain locked for long periods and in this case you might need to take action
to resolve the locked message.
To find and resolve locked messages on
a message point, use the administrative console to complete the following steps.
Procedure
- To find any locked messages, List the messages on the message point. The State property indicates whether or not a message is locked.
- To display extra information about a message, click its name in
the list. This displays the Messages [Settings] panel, which shows a range of properties of the message,
for example:
- Time stamp
- The time stamp of the message.
- Message wait time
- The time the message has been waiting to be consumed.
- If a message has remained locked for a long period, determine whether
you need to take action to resolve it:
- If a transaction ID is displayed with the message, this indicates
that the message is either being consumed or produced under the transaction
identified. If the message is being consumed, it is possible that the consuming
application has failed to commit the transaction which will leave the message
in this state until the transaction manager times out the transaction and
rolls back the consumption of the message. It is also possible, although less
likely, that the transaction has become in-doubt, in which case you might
need to take action to resolve it. See Resolving indoubt transactions for further information.
- If no transaction ID is displayed, the message is probably currently assigned to a consuming application connected to another messaging
engine in the bus. In this situation, the message is listed under one of this message point's known remote message points as a current message request.
If the remote messaging engine identified in the known remote message point is
currently unavailable, messages stay locked to it until the messaging engine
becomes available again. Check the state of the remote messaging engine to
ensure that it is started and communicating with the message point's
messaging engine.
What to do next
If appropriate, after resolving one or more locked messages, you
can delete these messages on the
Messages [Collection] panel.