>> Reading through the backlog, what you guys really want is >> something similar to zeroconf/bonjour -- have any of you >> thought of integrating it with Ganglia? >> >> http://developer.apple.com/opensource/internet/bonjour.html >> >> This is cross-platform, works on Mac OSX, UNIX, Windows. >> >> How I envision it to work is that gmond will register itself >> in the registry and when other gmonds or a gmetad come up, >> they will automatically configure based on some internal >> identifiers. This should eliminate the need for >> configuration files (static or dynamic), DNS (forward and >> reverse), /etc/hosts file, etc.
I was reading the internet draft about how it works through DNS and this does sound rather way cool. >This appears to be more of a service discovery solution than a full >configuration solution. Yes, I agree. Though there is a TXT area, it is only a few bytes and not designed to hold larger things like ganglia configs. There would still need to be a web service for handing out the configs, and I think this is all that would need to register. >There are a few ways it could work: > >- gmetad could discover all the gmond nodes, and pick one at random for >collection of data over TCP My gmetad wrapper adds up to 12 random hosts to the data_source lines to collect from multicasting clusters. More than that can segfault gmetad. And it can run a gmond listener for unicast clusters to report to. But I don't think it would be necessary for any gmonds to register... >- the gmond nodes could discover a configuration server's name >(regardless of whether it is HTTP, LDAP or something else) and then send >a request to that server for a list of parameters (e.g. cluster name, >multicast subnet, TTL) - this would be in one of my configuration >modules Yes, only the gmetad configuration server would need to register. It will know the gmonds because they will all ask for a configuration to run through the web service. The web service then [re]starts any needed gmetads on the server, and sends the client the correct gmond config to run. >However, I'm not sure that it solves the problem 100%. If I have 10 >servers on the same subnet/switch, 4 servers belong in cluster A and 6 >servers belong in cluster B, will Bonjour be able to tell each one the >correct answer? I don't know, but the new ganglia web service could. The site-central server should know which cluster to put each host in, based on hostname, IP address and maybe netmask or subnet which the client would provide in the request. >Maybe gmond should not know the cluster name at all - maybe gmetad >should have an internal table of cluster names and nodes. Exactly. My clusters are already defined centrally, per site (domain), even outside the scope of ganglia. My automation just converts those known clusters into the correct ganglia configuration files. So, I could imagine gmond and gmetad staying the same and the above is one way for Carlo's greaper to work. There would be a new web service added to the gmetad server to manage site configuration. Since it knows all greapers that have requested configuration, it could notify them when their configuration has changed (all greapers could listen on a fixed port). They would then request the updated configuration and restart their gmond. Actually, this would even work without auto-discovery if the clients can be pointed to a static configuration server when they start up. This would work well where each domain has one ganglia gmetad server (which is how I do it). It would be more complicated if you are trying to spread the load over multiple gmetad servers in one domain as the clients would need to know which one to talk to. -twitham ------------------------------------------------------------------------- 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-developers mailing list Ganglia-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-developers
