FMA's Historical Diagnosis
By user9148476 on Jan 29, 2010
And, time to talk about a very cool FMA feature I've been meaning to blog about for a while. It's been termed "historical diagnosis". The crux is having FMD reduce the number of convicted suspects in multi-entry suspect lists by comparing the historical record of other faults diagnosed on that system. When certain correlations are found, FMD auto-acquits some of the suspects in various suspect lists.
Probably best dealt with via an example. Suppose a suspect list is issued indicting two components, FRUA and FRUB. Some time later, another suspect list is issued, this time only indicting FRUA. FMD will discard the newer, single entry suspect list as a duplicate and acquit FRUB in the original suspect list. The end result, only FRUA is indicted. (And yes, component serial numbers are used to ensure the "old" FRUA is the same as the "new" FRUA.)
There are of course many different use cases with variations when the FRUs in the suspect list are in different states (faulty|isolated|replaced|acquitted), but you get the idea. And what's very nice is that all of this is managed by FMD itself. No changes to diagnosis rules or response agents. The changes incorporated into build 125.