Enterprise Administration > File Vaulting and Replication > Replication > Understanding Replication > Out-of-the-box Background Queues for Replication
Out-of-the-box Background Queues for Replication
This section describes the queues that are established when your Windchill solution is installed.
DeliveryStatusOnStartup
The DeliveryStatusOnStartup queue is used by content replication for the removal of failed or undelivered messages. The queue starts shortly after the method server starts and works through all of the failed or undelivered messages.
References to the internal content replication messaging system are placed in the queue entries. If there are failed entries, this means that not all failed messages could be deleted. The failed entries can be removed from the queue. When the method server is restarted, all of the necessary information will be gathered again.
There are two scenarios when the DeliveryStatusOnStartup queue is heavily used:
When the main site method server is restarted after the remote site becomes unavailable during a content replication run.
When the main site method server is restarted after it was restarted during a content replication run.
PurgeScheduleHistoryQueue
The PurgeScheduleHistoryQueue is used by external vaulting and content replication to track and clean up information about the old (outdated) schedules for revaulting and content replication. The queue contains only one object at a time.
A failed queue entry is an indication that old schedule histories could not be removed.
Checking for failed entries in this queue is not needed. If an entry in the queue is in a failed state, it will be recreated the next time the method server starts.
Maximum Queue Values
The following table shows properties that set the maximum number of process or schedule queues performed by the queue service. Depending on your requirements, you may need to reset these properties from their default values.
If you are not setting properties through a graphical user interface or in a mapping file, you add or edit properties with the xconfmanager utility. For more information, see Using the xconfmanager Utility.
The values of these properties have no upper limit, but increasing their size decreases performance. If you see errors that are presented as Max ProcessQueues Exceeded, increase the value of the wt.queue.max.processQueues property. If you see errors that are presented as Max ScheduleQueues Exceeded, increase the value of the wt.queue.max.scheduleQueues property.
Both types of errors are displayed in the method server log. Most errors of the Max ScheduleQueues Exceeded type appear in graphical messages, while most errors of the Max ProcessQueues Exceeded type do not appear as graphical messages.
Property
Description
wt.queue.max.processQueues
Sets the maximum number of process queues (24) that the queue service creates before throwing an exception. The default value is 12.
wt.queue.max.scheduleQueues
Sets the maximum number of schedule queues (24) that the queue service creates before throwing an exception. The default value is 12.
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