Data collection dynamics

When starting and stopping collections, a start/stop collection request can override a previous request so that the overall set of collections can be refined over time. For example, collections may be started for all resources in a major category, then be overridden by stopping collection on an individual resource. In this case, collections are in effect for all resources except the resource that is explicitly stopped.

VTAM® tracks the following information for each RTP connection, virtual route, destination subarea, or VTAM Global subcategory:

Collection enablement (whether VTAM should gather data)
SMF enablement (whether data should be delivered at SMF intervals)
Blocked route enablement (whether data should be delivered when the virtual route becomes blocked or unblocked).

For each VTAM Global Data subcategory:

Collection enablement is determined by the most recent request to start or stop data collection of the subcategory.
SMF enablement is determined by the most recent Start Performance Data Collection CNM RU specifying the subcategory.
Blocked route enablement does not apply.

For each virtual route:

Collection enablement is determined by the most recent request to start or stop data collection which includes the route within its target resource set.
SMF enablement is determined by the most recent Start Performance Data Collection CNM RU (except those specifying blocked route switching only) which includes the route within its target resource set.
Blocked route enablement is determined by the most recent Start Performance Data Collection CNM RU (except those specifying SMF switching only) which includes the route within its target resource set.

The information tracked for virtual routes is also tracked for destination subareas, except when specified on a single virtual route request. Tracking information is kept so it can be applied to any virtual route that is defined dynamically under a destination subarea. For each RTP connection:

Collection enablement is determined by the most recent request to start or stop data collection which includes the connection within its target resource set.
SMF enablement is determined by the most recent Start Performance Data Collection CNM RU which includes the connection within its target resource set.
Path switch enablement is determined by the most recent Start Performance Data Collection CNM RU (except those specifying SMF switching only) which includes the connection within its target resource set.