Lucas and I were talking over jira [1] which has to do with
metrics/alerting scale. This was discussed a bit on IRC recently as
well. Today, metrics publishes all datapoints to the bus (metrics and
avail go to different topics). The only consumer of that data is
alerting, and it consumes a small fraction of the total data (actually
it consumes none of it OOB at the moment, but that will hopefully change
as Lucas's alerting work comes on line in MIQ).
Although in its purest form this publish-it-all is the essence of bus
publishing, we both feel it's an unnecessary waste of resources, as
metrics can reach very high volume. There are a few approaches to
reducing the publishing/filtering that we're currently doing. The
options we discussed boil down to:
* No Publishing
o Just query metrics for the data needed for alerting (or whatever
other external use we may have for the data)
o This is essentially a polling approach with frequent polling
* Demand Publishing
o The "just tell me what movie you want to see" approach
o Let clients request the metric ids it wants published to the bus
I'm purposefully not going into much detail at this point. I'd rather
we talk out a preferred approach between these two, or something not
presented. But we'd like to move away from the current publish-it-all
approach.
[1]
https://issues.jboss.org/browse/HWKALERTS-118.