Aha! just pop the cheque in the mail...
regards, Richard Quoting Paul Choi <[EMAIL PROTECTED]>: > Well, Richard, you got me there. You certainly have delved into it much > more than I have. > > I think your explanation also explains why sometimes I see some host go > down and come back up randomly. > > -Paul > > -----Original Message----- > From: richard grevis [mailto:[EMAIL PROTECTED] > Sent: Thursday, September 20, 2007 5:11 PM > To: Paul Choi > Cc: [email protected] > Subject: Re: [Ganglia-general] Overriding hostname > > > Are you sure it works fine Paul? > > In gmond, the index (key) for stored host data is the host IP address. > If your hosts with multiple IP addresses only ever use one of address, > then yes, all will be fine. > > But if the source IP flips between the IPs occasionally, then any or all > of this happens: > > - The headnode will have entries for each IP seen from the multi NIC > host. If you netcat the headnode you will find entries for each IP > with each of them having the same hostname. Gmetad does not like this. > - As the headnode indexes by IP, each of the entries only gets data some > of the time. It will end up looking like these hosts are going up and > down. > - Unlike gmond, gmetad "indexes" by hostname, so at the very least you > will > have /var/log/messages filling with the RRD update error of a second > data update at the same wallclock time. > - At one stage gmetad would also abandon parsing the cluster XML stream > at that point, meaning that the cluster view may have many hosts > missing. > > I hacked a fix for this so that gmond saved data indexed by hostname. > If you want the hack then a Matt Toy can supply it, but it was for > ganglia 3.0.4 > > regards, > richard > > -- > kind regards, > Richard > > > Quoting Paul Choi <[EMAIL PROTECTED]>: > > > I have reverse lookups for both interfaces and Ips. Reverse DNS > mapping > > is fine. > > > > Maybe rather than manually overriding hostname, it might be easier if > > there's a way to have gmond send packets to other gmond(s) using a > > specific interface. > > > > -Paul > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of > > richard grevis > > Sent: Wednesday, September 19, 2007 9:45 PM > > To: Matt Cuttler > > Cc: [email protected] > > Subject: Re: [Ganglia-general] Overriding hostname > > > > > > Are you sure? As I remember it, the hostnames are generated by a > reverse > > dns lookup on the headnode (or whichever node you poll). You can play > by > > netcatting (nc) the headnode 8649 as well as the gmetad node 8651 and > > having a look. > > > > I think it is true that a reverse DNS mapping can't be specified in > any > > /etc/hosts file. Is that correct? At my last job, software did not > > generally do reverse lookups, so when ganglia came along it was us > that > > discovered all the bad reverse DNS entries. > > > > There have been discussions earlier about getting each gmond to send a > > hostname rather that using the source address and reverse DNSing it on > > the headnode. > > One gets all sorts of boring problems like bad engineering hostnames > > rather than nice ones, and if you hasve multiple IP interfaces/NICs on > a > > node then hostnames may flip around. That makes it look like hosts are > > coming up or going down when they are not. > > > > regards, > > Richard > > -- > > kind regards, > > Richard > > > > > > Quoting Matt Cuttler <[EMAIL PROTECTED]>: > > > > > Paul Choi wrote: > > > > Hi, > > > > I was wondering if there's a way to override hostnames of the > > reported > > > > client hosts? > > > > For example, > > > > I have a host named db02b. (10.1.5.7). And a virtual interface > > eth0:0 > > > > with 10.1.3.3. The IP 10.1.3.3 maps to another name du02. > > > > > > > > Right now, Ganglia shows the host as db02b. But I'd like to show > it > > as > > > > du02 (the eth0:0 IP). > > > > > > If I remember correctly, modifying the /etc/hosts file on the > machine > > > running gmetad will work.. > > > > > > -Matt Cuttler > > > > > > > > > ------------------------------------------------------------------------ > > - > > > This SF.net email is sponsored by: Microsoft > > > Defy all challenges. Microsoft(R) Visual Studio 2005. > > > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > > > _______________________________________________ > > > Ganglia-general mailing list > > > [email protected] > > > https://lists.sourceforge.net/lists/listinfo/ganglia-general > > > > > > > > ------------------------------------------------------------------------ > > - > > This SF.net email is sponsored by: Microsoft > > Defy all challenges. Microsoft(R) Visual Studio 2005. > > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > > _______________________________________________ > > Ganglia-general mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/ganglia-general > > > > > ------------------------------------------------------------------------ > - > > This SF.net email is sponsored by: Microsoft > > Defy all challenges. Microsoft(R) Visual Studio 2005. > > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > > _______________________________________________ > > Ganglia-general mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/ganglia-general > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Ganglia-general mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/ganglia-general > ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Ganglia-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ganglia-general
