[Engine-devel] Design review summary for 3.2 - adding support for External Events

[Frantz, Chris]

Eli,

I've reviewed the Detailed Design for External Events.  Overall, the design looks good, but I have a few questions:

1. Can I provide additional data with the event:

AuditLogSeverity = EXTERNAL_EVENT_WARNING
Message = "Enclosure RACK15ENC3: Fan in bay 5 failed"
Vendor = "HP"
CustomEventId = 12345
DataCenterId = "Houston" (I assume this is really the UUID of the data center)
ExtraData = { "enclosure": "RACK15ENC3", "bay": 5, "partnum": "412140-B21", "spare": "413996-001", "model": "Active Cool 200 Fan", "zone": 2}

2. What is the meaning of this statement on the DetailedDesign page:

External Events can not use application variables, therefore no '$' expressions should appear in the Event/Alert free message text

Does this mean the Message has to be fixed text with no substitution variables?  Can I do this:

Message = "Enclosure {ExtraData.enclosure}: Fan in bay {ExtraData.bay} failed.  Replace with {ExtraData.spare}."

3. Considering that the Event has a number of IDs associated with it (UserId, DataCenterId, HostId, VmId, etc), does that mean an event can be associated with multiple entities at once?  "Host X in Cluster Y in Datacenter Z has exceeded the critical temperature threshold.  Shutting down."

How will this be expanded in the future as oVirt Engine becomes aware of more types of entities (enclosures, rack managers, advanced networking switches/fabrics)?  Is it be possible for an event to be associated with multiple hosts?

To return to the fan failure scenario above, if a fan in an enclosure fails, all of the hosts in that fan's fanzone will be effected.

Thanks,
--Chris