Integration Server 10.11 | Publish-Subscribe Developer’s Guide | Exactly-Once Processing for Documents Received by webMethods Messaging Triggers | Overview of Exactly-Once Processing | Document History Database | What Happens When the Document History Database Is Not Available?
 
What Happens When the Document History Database Is Not Available?
If the connection to the document history database is down when Integration Server attempts to query the database, Integration Server considers the lack of availability to be a transient error in the preprocessing phase of trigger execution. How Integration Server handles the error depends on the configured transient error handling for trigger preprocessing.
For more information about transient error handling during trigger preprocessing, see Transient Error Handling During Trigger Preprocessing.