Event sequencing

When a set of events is sent to IBM® Business Monitor from the same event producer, such as an instance of a process, it is typically important that the events be processed in the order in which they were produced. Events can erroneously be delivered to a monitor model in the wrong order for several reasons, such as asynchronous event emission and network delays. For models where event order is important, incorrect event sequence order can result in model processing exceptions and incorrectly calculated data. IBM Business Monitor has a mechanism for putting the events back into the correct order for processing.

To illustrate the effects of event order, note the following example. If metric A defaults to 3, and event 1 sets metric A to 5, and then event 2 sets metric B to 2 * A (2 times metric A), there are two possible outcomes. If all events arrived in the correct order and event 1 was followed by event 2, then metric B is correctly set to 2 times 5, or 10. If the events arrived out of order and event 2 was followed by event 1, then metric B is incorrectly set to 2 times 3, or 6.