Sorry, my phrasing in the last mail was a bit poor. The trace snippet is from gmtric when it transmits the UDP packet.
What I was trying to say was that even when a metric is string encoded, it takes fewer bytes than the corresponing XML snippet. I do realise that the UDP stuff is optimised to only transmit when a value changes though, but overall I don't see how string encoding really matters. kind regards, Richard > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of Grevis, Richard: IT (LDN) > Sent: 12 February 2007 12:04 > To: [EMAIL PROTECTED]; > [email protected] > Cc: [EMAIL PROTECTED] > Subject: Re: [Ganglia-developers] A native windows gmond > > > Alex/Paul, > > gmetric trace snippet (strings, not binary): > > connect(4, {sa_family=AF_INET, sin_port=htons(8659), > sin_addr=inet_addr("10.125.85.27")}, 16) = write(3, > "\0\0\0\0\0\0\0\5float\0\0\0\0\0\0\20procs-per-se"..., 72) = 72 > > Now netcat of headnode of above cluster snippet: > <METRIC NAME="procs-per-second" VAL="9" TYPE="float" > UNITS="procs/sec" > TN="10" TMAX="5" DMAX="300" SLOPE="both" > SOURCE="gmetric"/> equals more than 72 bytes. > > If I understand this correctly, it means that the XML stream > contributes as much to network load as gmond's UDP traffic. > > kind regards, > Richard Grevis > Production Architecture > Barclays Capital. > > > > -----Original Message----- > > From: Paul Millar [mailto:[EMAIL PROTECTED] > > Sent: 10 February 2007 18:34 > > To: [email protected] > > Cc: Alex Balk; Grevis, Richard: IT (LDN) > > Subject: Re: [Ganglia-developers] A native windows gmond > > > > > > Hi Alex, > > > > On Thursday 08 February 2007 18:31, Alex Balk wrote: > > > Why would you consider gmetrics to be "second class"? I > > find those to > > > be much more useful than the builtin metrics. > > > > Ah, sorry; a slight misunderstanding here. > > > > I'm considering gmetric metrics as "second class" just > > because of how the > > metrics are XDR-encoded for their transport to a gmond. I'm > > not saying > > they're less useful than the gmond-provided metrics, just > > that they're > > treated differently when encoded into the UDP multicast packet. > > > > gmetric metrics are always encoded as Strings ("string value<>" in > > protocol.x). For number-based metrics, this can be very space-wise > > inefficient. A binary format would be better, and this is > > what the "core" > > metrics use. > > > > Currently, only "core" metrics can be binary encoded. One > > can only extend the > > list of core metrics by forking ganglia and make a version > > that's pretty much > > incompatible with the ganglia.sf.net version (with the > caveat that a > > ganglia.sf.net-gmond can still publish to the new gmond, > > allowing some level > > of interoperability). This is the Swiss binary-only Windows > > version of > > gmond. > > > > Simply allowing gmetric data to be binary encoded would be a great > > improvement; but, perhaps a better approach would be to > > rethink the encoding > > so they're no explicit mention of gmond metrics: none of the > > metrics would be > > more important than others. > > > > > In fact, the only thing > > > that's nice about builtin metrics (other than the fact that > > you get them > > > out-of-the-box) is that they get reported even when the > > machine is under > > > extremely high load. > > > > Hmmm: interesting. How are you sending gmetric data? Are > > you running gmetric > > from cron? How are you generating the metrics? Do you > know how much > > overhead is involved sending gmetric data? > > > > I've my own low-overhead gmetric-like solution (monami) that > > should just keep > > on chuggin', like gmond, even when the machine is heavily loaded. > > > > So, I'm interested in how monami does in difficult high-load > > situations. > > Perhaps we could talk more off-line about this if its going > a little > > off-topic for the list. > > > > > I view Ganglia as a framework rather than a performance monitoring > > > solution. Anything can be encoded in the UDP messages > > through the use > > > of gmetric, and specialized web interfaces can be quite > > easily built > > > through the use of the "custom metrics addon" I'd written a > > while back > > > ( http://wtf.ath.cx/screenshots.html ). So you can not only > > access the > > > XML data on machine, cluster & grid levels, you can also generate > > > whatever UIs you want for your users... regardless of whether the > > > metrics are hardcoded or brought in from gmetric. > > > > Yes, sure. I'd imagine some people look at Ganglia as a > > complete solution, > > others as a building block. > > > > Its really just a question of at what point is the > > distinction between gmond- > > and gmetric- generated metrics lost? > > > > When gmetad reads XML from a gmond, data from both sources is > > pretty much > > equivalent (except for the SOURCE attribute). After then, > > the data should > > hit rrdtool as equivalent. > > > > Thereafter, the only different being the default web-pages > > are setup to expect > > core metrics and display them nicely. This is where you're > > custom metrics > > addon comes in useful. > > > > > The only thing left on my wishlist is support for 64bit > metrics, to > > > achieve better scalability over aggregated data. > > > > BTW, you might want to add a wish-list/todo bugzilla entry, > > just so it doesn't > > get lost. > > > > Cheers, > > > > Paul. > > > -------------------------------------------------------------- > ---------- > For more information about Barclays Capital, please visit our > web site at http://www.barcap.com. > > Internet communications are not secure and therefore the > Barclays Group does not accept legal responsibility for the > contents of this message. Although the Barclays Group > operates anti-virus programmes, it does not accept > responsibility for any damage whatsoever that is caused by > viruses being passed. Any views or opinions presented are > solely those of the author and do not necessarily represent > those of the Barclays Group. Replies to this email may be > monitored by the Barclays Group for operational or business reasons. > -------------------------------------------------------------- > ---------- > > -------------------------------------------------------------- > ----------- > Using Tomcat but need to do more? Need to support web > services, security? Get stuff done quickly with > pre-integrated technology to make your job easier. Download > IBM WebSphere Application Server v.1.0.1 based on Apache > Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&; dat=121642 _______________________________________________ Ganglia-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ganglia-developers
