Event Spool Database

Universal Event Monitor (UEM) records its monitoring activity in the event spool database.

It is possible for UEM to detect multiple occurrences of any single event that it monitors. UEM creates a record in the spool database for each event occurrence that it detects and tracks. UEM maintains the current state of an event occurrence from initial detection through the completion of any event handlers.

If an event definition goes inactive before UEM detects any occurrences of that event, UEM creates a single spool entry to record the expired event.

Universal Broker applies all updates to the event spool database. A UEM Server is responsible for sending the Universal Broker all relevant information, along with the required database operation (add, update, or delete).

Typically, any spool records created for an event are deleted when the Broker detects the completion of the UEM Server that monitored the event. However, when an event-driven UEM Server completes, any records that indicate work in progress (for example, tracking of an event occurrence, execution of an event handler) are retained for possible recovery when the event-driven Server is restarted. For additional information on recovery of event spool records, see Universal Event Monitor Server.

A Stonebranch Tip

An option can be set in the Universal Broker's configuration to prevent it from deleting any event spool records when the UEM Server component completes. Setting the comp_info_retention option to a value greater than 0 causes the event spool record to be preserved.

Because there is currently no database cleanup routine available, this option should be set only following a recommendation from, and with the assistance of, Stonebranch Inc. Customer Support.

Feedback from a demand-driven UEM Server is returned to the UEM Manager that initiated the monitoring request. In this situation, event spool records are simply another means of following the progress of the event and any detected occurrences.

However, for an event-driven UEM Server that has no client, the records in the event spool database are the best way to monitor the status of the work performed by that UEM Server. Because an event-driven UEM Server typically is a long-running process, an adequate history of the UEM Server's activity can be obtained by viewing the spool records.

Currently, event spool records can only be viewed with the Universal Spool List utility (uslist). Information on using Universal Spool List to view event spool records can be found in Universal Event Monitor Server. For information on all Universal Agent utilities, see the Universal Agent Utilities 7.3.x Reference Guide.