Maintaining and monitoring IBM Business Process Manager Event Manager
You can use the Event Manager monitor that is included in the Process Admin Console to troubleshoot processes that are supposed to run automatically (for example through an undercover agent) but fail to start. You can use the Event Manager monitor to identify underlying problems as well as controlling various aspects of Event Manager processing.
The Event Manager is the component of the Process Server that handles event scheduling and queuing. For example, when an event is received by Process Server, that event is translated to a job in the Event Manager. Each job in the Event Manager is routed through a Scheduler, which schedules and tracks the execution of its assigned jobs.
| For... | Event Manager... |
|---|---|
| Incoming message events from external applications | Queues incoming messages and then kicks off the appropriate UCA. |
| Schedules set in UCAs | Looks to find the next UCA to run, calculates the time until the next UCA is due to run, and is dormant for the time between. |
| Incoming subscription events from external ECM systems (through the RESTFul API send ECM event) | Queues an asynchronous message and initiates the appropriate event subscription and attached service. |
The following diagram shows how the Event Manager receives and processes incoming requests:
The scheduling and driving of the work is accomplished with Event Manager tasks. When an exception occurs, such as a queue-full condition of the monitor event queue, a re-execution of the particular tasks is triggered, which attempts to overcome the exception. The re-execute-limit property that is specified in the Event Manager configuration settings determines the number of times to try again (set to 5 by default). After that limit is reached for an Event Manager task, it is not tried again. Event Manager tasks that fail and reach the re-execute-limit are put on hold. The tasks are retained in the database, but they are flagged to be on hold and are only rescheduled when the BPMReplayOnHoldEMTasks command is run. If an Event Manager task is put on hold, the failure indicates a possible infrastructure problem. Either a resource is temporarily unavailable or the system configuration has an issue (for example, not enough connections). If an Event Manager task is put on hold, the process instance might stop responding.
- Monitoring the Event Manager
The Event Manager monitor in the Process Admin Console displays information about the Scheduler for the Event Manager on your Process Center server or Process Server and about the various jobs being tracked by that Scheduler. - Creating and maintaining blackout periods
Administrators should establish blackout periods to specify times when events cannot be scheduled, for example, due to a public holiday or when regular system maintenance is scheduled. The Event Manager takes blackout periods into account when scheduling and queuing events, event subscriptions, and undercover agents (UCAs). - Creating and maintaining execution queues
Event Manager jobs are scheduled to be processed by an execution queue. (If you look at the job listing in the Event Manager monitor, you can see that each job is assigned to a job queue.) - Event Manager configuration settings
To understand how the IBM Business Process Manager Event Manager works, review the configuration properties. 
Managing on-hold Event Manager tasks
You can list, replay, and delete on-hold Event Manager tasks by using either REST API calls or administrative commands.- Tuning databases for the Event Manager
If the IBM Business Process Manager Event Manager has poor performance, you can tune the databases by updating optimizer statistics, reorganizing the tables and indexes, providing your database system with a better index, or, on Oracle databases, reducing the contention.