Event handling

The connector logs information about successfully processed IDocs in a JMS-MQ event message (in the queue specified in the SAPALE_Event_Queue configuration property) to the EventState.log file. This file is located in the directory specified in the AleEventDir configuration property.

Note:
Each event message can contain multiple IDocs, each of which represents a business object.

If the connector goes down before it processes all IDocs in the current event message, it uses the EventState.log file during recovery to ensure that it sends each IDoc only once to the integration broker.

Important:
The connector does not create the log file automatically the first time it processes an event. You must create this file for before you run the connector for the first time.

The format of the log file is:

TID: OS, 1S, 2F, 3U
 

where <TID> is the current transaction ID being processed, and each number represents the sequence number of all work units in the event message.

For example, if the connector has successfully processed three of the first four IDocs in the current event message, the second IDoc failed processing, and the connector has not yet finished processing the current event message the EventState.log file might show:

<TID> :: OS, 1F, 2S, 3S
 

If the connector went down before processing the entire event message, at startup the connector will use the information in the log file to resume processing the events in the message at the point where it had stopped processing. The connector reads the log to get the transaction ID of the event to be recovered, the latest work unit, and the status of each work unit. Then the connector begins sending to the integration broker the business objects that represent each IDoc in the event message with a sequence number greater than the last number in the log file. In the previous example, the connector will processing the fifth IDoc in the current event message.

The connector keeps the contents of the log file in memory to enhance performance. It accesses the file on disk only to update it with a new entry. The connector reads the log file only at recovery time.

For information on how the connector uses the EventState.log file in the recovery process, see Failure recovery.

Copyright IBM Corp. 1997, 2004