david- i suspect that your nodes are not multicasting to one another. when you connect to the XML port on the gmond process do you data for every host in your cluster? if your nodes are not multicasting to one another then you should only see the data for the host you are connecting to. there are many reasons why your nodes might not be multicasting: multicast support taken out of the kernel (only a problem if you built a custom kernel yourself and intensionally took out multicast support.. all stock linux kernels support multicast), ipchains may be blocking multicast traffic, your network equipment might not be configured to pass on multicast traffic (talk with your network admin to make sure multicast is enabled.. by default most equipment has it turned on).
a brief statement about ganglia's security model.. gmond will not accept connections to port 8649 from hosts that it has not received multicast packets from. only hosts on the ganglia multicast network are allowed to get the XML data. if you try to telnet to a remote host and it closes the connection then your multicast is not working. let me know if there is anyway that i might be able to help. you also might want to chat with your local network guru. good luck! -matt Today, David Abbishaw wrote forth saying... > Hi, > > I've installed ganglia (gmond) onto some of my clusters nodes using the rpm, > (OS is Redhat 7.1) > and followed the instructions to configure the webserver stuff on my front > end machine, all works OK, > except that the web interface is only reporting about the front end nodes > where its installed. > > Whilst trying to cure the problem I discovered that each of the nodes can > telnet to localhost 8649 > and get what appears to be a correctly formatted XML output containing the > nodes metrics, however the same test > done between 2 nodes will fail, it seems that gmond is only accepting > requests from local connections. > > Any ideas would be gratefully received, as looking at the reports for the > front end machine this tool > looks great! > > Thanks > David. >
