Another thing I've found is turning multicast on in too many places in order to make ganglia work is a bad thing. Turn multicast on in the segments you need it, use ganglia's multicast-unicast feature to move the data across your routed segments...keeps from throwing multicast data hither and yon. Hope it helps. --dio
On Thu, 2004-05-06 at 09:09, James Casbon wrote: > 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. > > > ------------------------------------------------------- > This SF.Net email is sponsored by Sleepycat Software > Learn developer strategies Cisco, Motorola, Ericsson & Lucent use to deliver > higher performing products faster, at low TCO. > http://www.sleepycat.com/telcomwpreg.php?From=osdnemail3 > _______________________________________________ > Ganglia-general mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/ganglia-general > >
