Designer 10.15 | webMethods Service Development Help | Properties | webMethods Messaging Trigger Properties | Exactly Once Properties
 
Exactly Once Properties
In the Properties view, under Exactly once, configure exactly-once processing for a trigger. Exactly-once processing ensures that a trigger processes a guaranteed document once and only once. Integration Server provides exactly-once processing by determining whether a document is a copy of one previously processed by the trigger. Designer provides three duplicate detection methods: redelivery count, document history, and a document resolver service.
Property
Description
Detect duplicates
Enables exactly-once processing for the trigger and instructs the server to check a document’s redelivery count to determine whether the trigger has received the document before.
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To...
True
Specify that exactly-once processing is provided for documents received by this trigger and instructs the server to check a document’s redelivery count to determine whether the trigger received the document previously. The redelivery count indicates the number of times the routing resource has redelivered a document to the trigger.
False
Specify that exactly-once processing is not provided for documents received by this trigger.
Use history
Indicates whether a document history database will be maintained and used to determine whether a document is a duplicate.
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To...
True
Indicate that Integration Server maintains a history of documents processed by the trigger. When the trigger receives a document, Integration Server compares the document’s universally unique identifier (UUID) to the UUIDs of documents processed by the trigger. If there is a match, the Integration Server either determines the second document is a duplicate and discards it or, if the first document has not finished processing, marks the second document’s status as In Doubt.
False
Indicate that Integration Server does not maintain a document history database. The Integration Server will not use document history to determine whether a document is a duplicate of one already processed by the trigger.
Note:
To perform duplicate detection using a document history database, the audit subsystem must be stored in a relational database and Integration Server Administrator must define a JDBC connection pool for the Integration Server to use to connect to the document history database.
History time to live
Specifies the length of time the document history database maintains an entry for a document processed by the trigger. During this time period, Integration Server discards any documents with the same universally unique identifier (UUID) as an existing document history entry for the trigger. When a document history entry expires, Integration Server removes it from the document history database. If the trigger subsequently receives a document with same UUID as the expired and removed entry, the server considers the copy to be new because the entry for the previous document has been removed from the database.
Document resolver service
Specifies the service that you created to determine whether message’s status is New, Duplicate, or In Doubt. Click to select a service from a list.
The document resolver service must use the pub.publish:documentResolverSpec to define the service signature.
Related Topics
General Properties for webMethods Messaging Triggers
Trigger Queue Properties
Message Processing Properties
Fatal Error Handling Properties
Transient Error Handling Properties
Exactly Once Properties