I'm pretty sure it is the cause. I was told about the network problem, looked for unusual connections, found the one to 239.2.11.71, turned ganglia off, asked the network guy if things were better which he says they were.
Whats a good way of monitoring the multicast traffic to see what effect the changes have? James On Wednesday 05 May 2004 18:45, Jason A. Smith wrote: > I don't think this is exactly correct, each gmond "broadcasts" only its > own data, at precompiled intervals based on how much the value has > changed and how long since the last broadcast. Setting the deaf mode > only makes it not listen to the broadcasts from nodes on the multicast > channel that is joined (including itself). The only way to reduce the > multicast traffic, besides patching & recompiling the sources, is to set > the node as mute. If you do this though, the only way to get its data > is to poll it directly over tcp to get the xml dump of the data that it > has been listening to and collecting. > > Are you sure that ganglia is really the cause of your problem? We have > ganglia installed on a cluster with 368 nodes on a single subnet and > only see an average of about 68 ganglia multicast packets per second. > > ~Jason > > On Wed, 2004-05-05 at 12:58, Paul Henderson wrote: > > I don't know if this is simplifying things too much, or just a dumb > > reply, but the problem I've seen with ganglia is that every host in the > > cluster is listening to every other host in the cluster and broadcasting > > all the information, causing a lot of traffic (160 nodes in my cluster). > > So what I've done is make 158 nodes "deaf" by editing the gmond.conf > > file and setting "deaf on", then restarting the gmond on each. Now only > > two nodes are listening to traffic and broadcasting all data, and the > > other 158 nodes are just sending out their own data. This reduced the > > traffic considerably. My network folks are happier.
