About Suspending and Resuming Document Retrieval for All Triggers
When you suspend document retrieval for all the webMethods messaging triggers on an Integration Server, the Integration Server stops retrieving documents from the Broker and Universal Messaging. Integration Server resources, such as threads and memory, that would have been used for document retrieval are available for other tasks.
Suspending document retrieval for all webMethods messaging triggers is a quick way to free up server resources. This can be especially helpful in a situation in which the Integration Server is functioning under heavy load and additional resources are needed immediately.
Suspending or resuming document retrieval can be a temporary or permanent change. (Integration Server considers a document retrieval change to be permanent if you selected the Apply Change Permanently check box when you made the change.) If the change is temporary, Integration Server reverts to the permanent document retrieval state when Integration Server restarts or you reload a package. When you reload a package, Integration Server reverts only the webMethods messaging triggers contained in that package to the permanent document retrieval state. For example, suppose that you temporarily suspend document retrieval for all webMethods messaging triggers. If you reload the package OrderProcessing, Integration Server resumes document retrieval for the webMethods messaging triggers in the OrderProcessing package only.
Tip: On the Settings > Messaging > webMethods Messaging Trigger Management page, under Document Retrieval, Integration Server Administrator indicates a temporary document retrieval change by displaying an asterisk (*) next to the trigger status in the Active column.
You can gradually resume document retrieval by setting the Queue Capacity Throttle to a low percentage, such as 10%, and then resuming document retrieval for all webMethods messaging triggers. Integration Server resumes document retrieval at the adjusted capacity for all webMethods messaging triggers. You can also gradually resume document retrieval by selectively resuming individual triggers. For example, you might want to first resume document retrieval for those triggers that are part of a critical or high priority process.
Before suspending or resuming document retrieval, keep the following information in mind:
Suspending document retrieval affects document retrieval from the messaging provider only (
Broker and
Universal Messaging).
webMethods messaging trigger will continue to receive locally published documents. Additionally,
webMethods messaging triggers will continue to receive documents delivered to the default client.
When you suspend document retrieval, documents to which this trigger subscribes will collect on the messaging provider. Documents remain on the messaging provider until document retrieval resumes for the trigger or the documents expire.
If you suspend document retrieval for a trigger, but do not suspend document processing for the trigger, one of the following occurs:
If
Broker is the messaging provider, the trigger eventually processes all the documents that were retrieved from the messaging provider for the trigger
If
Universal Messaging is the messaging provider,
Integration Server rolls back all of the documents that have been retrieved but not acknowledged to
Universal Messaging. This includes unprocessed documents in the trigger queue and documents currently being processed. The documents that are in the midst of being processed will complete processing. However,
Integration Server cannot acknowledge the documents. This will lead to duplicates. After document processing resumes for the trigger, the documents are redelivered. If exactly-once processing is enabled for the trigger but a message history database is not used,
Integration Server determines that the redelivered documents are duplicate documents and rejects them.
To avoid the above situation where Integration Server receives duplicates of documents for which processing completed, suspend document processing before suspending document retrieval. When you suspend document processing for a webMethods messaging trigger that receives documents from Universal Messaging, Integration Server does not retrieve any new documents from the trigger queue for processing.Integration Server allows any documents already being processed to completes processing, which includes acknowledging the documents to Universal Messaging. After processing completes, then suspend document retrieval for the trigger. An active thread count of zero for the trigger indicates that document processing has completed.
Note: If Universal Messaging setting QueueDeliveryPersistencePolicy is set to “No Persist/No Sync” and the Universal Messaging server restarts before document retrieval resumes for the trigger, the documents that Integration Server rolled back to Universal Messaging will be lost.
When you resume document retrieval,
Integration Server resumes document retrieval for
webMethods messaging triggers at the percentage specified by the
Queue Capacity Throttle.
If you do not resume document retrieval before
Integration Server restarts, the trigger package reloads, or the trigger properties are modified, the messaging provider discards any volatile documents that it is holding for the trigger.