>>> On 11/10/2008 at 6:11 PM, in message <[EMAIL PROTECTED]>, Ofer Inbar <[EMAIL PROTECTED]> wrote: > Brad Nicholes <[EMAIL PROTECTED]> wrote: >> The reason why is because with the introduction of the modular >> metric functionality, metric metadata is now passed between gmonds >> rather than it being hardcoded into every gmond. In multicast mode, >> if you restart the master gmond, it has to request from and wait for >> each sub-gmond that is listening on the same multicast channel, to >> respond with its metadata for each metric it supports. Depending on >> the reporting interval for a collection group, this could take >> anywhere from a few seconds to several minutes. In unicast mode the > > However, as we discovered a couple of months ago, requesting new > metadata doesn't always work as designed, and it can take hours > to get everything it needs. Restarting the *other* gmonds in the > cluster is sort of a workaround, because each one will send its > metadata when it is restarted. This way, you can at least ensure that > the least recently restarted gmond knows everything. > -- Cos
That's interesting. I would like to investigate this further since I haven't seen the same problem. In my testing, granted I don't have very large clusters to test with, the complete metadata resync time has only taken as long as the long longest collection_group interval (ie. time_threshold value). If you don't have any collection_groups that have a time_threshold on the order of hours, then there is something we need to investigate further. It will just be a little more difficult because I can't duplicate the delay in my testing environment. BTW, another workaround if you don't mind the additional UDP traffic, is to set the send_metadata_interval value anyway, even in multicast mode. All it will do is ensure that the metadata is sent on an interval rather than just on request. This might be a good idea if you are restarted gmond's very often. Brad ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Ganglia-general mailing list Ganglia-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-general
