Stale messages

Implement a rule that checks for stale messages.

A stale message is one that is not being pulled off a queue.

Create a rule that triggers if the CurrentQDepth is greater than x AND the OpenInputCount is zero AND OpenOutputCount is zero. All three conditions must be true before the event occurs.

(CurrentQDepth>x)AND(OpenInputCount=0)AND(OpenOutputCount=0)

On the Triggers tab, the equation looks like the following figure.

Using the Duration Property of the end node: Assume you need to know if there are messages that have been sitting on a queue and are not being pulled off for more than 30 seconds. Use the end node properties dialog box. The end node properties dialog box allows you to specify the duration for an end node. Set the value to 30. The Duration option requires that a given trigger be true for the specified number of seconds before the trigger activates. A duration cannot be used if the trigger contains a delta operator.

When an event is triggered depends on when the event occurs, how long the duration is, and the sample interval. Assume that the duration is 30 seconds and the sample interval is 60 seconds. If an event occurs somewhere in the first 30 seconds of a sample interval, then the trigger pauses for 30 seconds and fire at the next sample interval (top example of the figure below).

If an event occurs somewhere in the last 30 seconds of a sample interval, then the trigger pauses for 30 seconds and fire at the next sample interval (bottom example of the figure below), which could be up to 90 seconds later.