KD2_PFnn_SH - Snapshot history

The KD2_PFnn_SH parameters control the snapshot history behavior in your environment.

Snapshot history data is useful, for example, if you want to examine activities leading to, and following, an exception without recreating the situation. The data is periodically stored by the OMEGAMON Collector in a wrap-around-managed snapshot history data set.

You can define how often the snapshots are stored by setting the sample interval time. The amount of stored snapshots depends on the snapshot data volume and the specified snapshot history data set size. When the defined maximum number of snapshots is exceeded, the oldest snapshot is deleted and the newest snapshot is added.

You can view this information through the history mode in the Performance Expert Client. This mode allows you to display recently stored snapshots at a specified point-in-time. You can then scroll forward and backward through the history of snapshot data to get a better understanding of what happened and to identify what caused the problem (for example, detected situations, bottlenecks, deadlocks, timeouts).