On a (very) slightly less pie-in-the-sky note...
Has anyone considered the utility of being able to select a subset of
cluster/host/metric data from the metadaemon? In other words, you
send a command that limits display to values that have been updated in
the last 60 seconds, or a particular cluster or host name. Any speed
hit from building the new response would probably be made up for in
the front-end. If you're viewing host details for one host out of a
900-host combined metadaemon XML feed, and the front end only parses
30 metrics instead of 2700... well...
It would mean rewriting the listen thread of gmetad (and,
simultaneously, the front-end) to have a full-duplex conversation and
there's some possible gotchas there... but what the heck, this is the
developer's list.
Anyway. Another great idea from the people who brought you beer
milkshakes...
Since Matt is going to be indisposed for a while due to his new baby, I
will take this one.
We are definately planning to implement this idea, and I'm glad you see
the need for it. Matt's idea, which I think is excellent, is to use
XPath to allow subset queries of the XML tree. Each gmetad would
understand XPath, and only return the portion of the tree that is
pertinent. Yes, this does make things more complicated, we need an
interactive protocol to the gmetad, but hey, we're designers.
Federico
