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Entry #338: If I can't use "IO Busy Pct," how do I determine NP % Busy?

If I can't use "IO Busy Pct," how do I determine NP % Busy?
The ViewPoint UNIT and SUBSYS statistics for NPs (Network Processors) are IO Time statistics. Based on the Unisys technical definition of IO time they are correct. This definition is that IO Time is the time from when the IO was handed to the DLP or Channel Adapter (in this case the NP) until the DLP/Channel-Adapter completed the IO operation.

Due to the nature of MCP-to-NP message communication, this definition will always result in odd IO times.

The whole concept of "IO Busy Pct" percent assumes that a unit's overall "processing" capacity is limited by its "IO Time" capacity. While this works for most IO devices, it does not work for the NPs where "IO Time" has no relationship to their ability to "process" communication messages.

The real issue is to determine how "busy" the NP is. Hence, rather than using the IO Time-based metric "UNIT Busy Pct for NPxxx" to judge this, it is far better to answer that question using the two BNALIB metrics "BNAC CPU Pct for host-icpxxx" and "BNAC Mem Pct for host-icpxxx" (ICPs are the same things as NPs).

These BNAv2 metrics show the actual internal CPU and Memory utilization for the NP (ICP). They are much better metrics for judging actual NP hardware utilization than the IO Time reported by the MCP for the NP.

NOTE: Both the ViewPoint UNIT IO counts (UNIT IO/Sec) and BNA message traffic statistics (BNAS MsgsIn/Sec, BNAS MsgsOut/Sec) are valid, and either can also be used to monitor the "processing" load on the NPs.