I have just proved that cascading event processing did indeed arrive with 2.4 (strictly it's 2.4.1 that I am using). However I cannot find any documentation for how it works and certainly no examples as suggested by Matt!
There are 2 different aspects to consider; event class transforms and event class mapping transforms. Pre 2.4, I believe it was relatively simple. Either a single class transform was used (if no event mapping took place ie event generated by Zenoss daemon), or an event mapping transform took place, in which case any class transform for the resulting class was ignored. If a class transform was used, it was simply a single transform - no cascading hierarchy of transforms. Now life is much more complicated. Ignore class mapping transforms for a moment. If you have a class hierarchy /Skills/S1/S2 and each of these has a transform, then, for an event of class /Skills/S1/S2 they are all applied, as Matt says, starting with the Skills transform, then the S1, then the S2. If a different private field is defined in each, then an event of class /Skills/S1/S2 will end up with all the private fields, a /Skills/S1 event will end up with those fields from /Skills and S1 but not S2, etc. If the same private field is defined in all the transforms, then the most specific wins ie. S2. Now introduce event class mapping transforms. In the past, if a mapping transform was used, any class transform was ignored. Now, BOTH the event class mapping and the event class transforms seem to be applied. Any private field that appears in both, the mapping transform takes precedence - OK so far. However, I find that a mapping transform may use a private field from the class transform - so the order is class then mapping??? But I also find that a class transform can make use of a private field from a mapping transform - so the order is mapping then class??? So, questions: 1) Please where is there some good documentation on the cascading event transforms that arrived in 2.4 but didn't even get a mention in the Release Notes? 2) What is the order of processing when you have both mapping transforms and class transforms? 3) Or is there something really clever goes on at database insertions time where all this gets sorted out? Cheers, Jane > > Matt Ray wrote, On 4/10/2009 4:11 PM: > Quote: > There are some changes being made to Event Transforms for 2.4. We're > working on getting some examples added to the documentation and I > don't think they're all in the beta yet. One of the changes will be > cascading event transforms. Event transforms are applied down the > event hierarchy, so that on an incoming /Business/Service/Bus event, > the /Business transform would be applied, then the /Service > transform, then the /Bus transform. This sounds like what you want. > > Thanks, > Matt Ray > Zenoss Community Manager > community.zenoss.com > [email protected] > -------------------- m2f -------------------- Read this topic online here: http://forums.zenoss.com/viewtopic.php?p=38958#38958 -------------------- m2f -------------------- _______________________________________________ zenoss-users mailing list [email protected] http://lists.zenoss.org/mailman/listinfo/zenoss-users
