>>> On 10/24/2008 at 7:57 AM, in message <[EMAIL PROTECTED]>, Ofer Inbar <[EMAIL PROTECTED]> wrote: > Recently we noticed something we don't know the explanation for, on a > CentOS4 for system running gmond 3.1.0: The Ganglia graph shows a line > for "running processes" that sometimes spikes to 10, 20, or higher, > and often stays at that high level for several samples in a row; but > top reports that processes "running" is 1-4 and occasionally 5 or 6, > but never shows a number as high as 10 even if we watch it for a while, > while the graph updates and clearly shows spikes. > > We found one cause of those spikes and fixed it, reducing their size > and number, so we don't think Ganglia is fabricating it. It's showing > something that's really happening. But why the disagreement with top?
One reason for this is probably because Ganglia specifically looks for spikes and then reports them. This is what the value_threshold directive in the .conf file is for. If the delta between the previous value and the current value ever spikes beyond a specified percentage, then gmond will immediately send the values for the collection_group that the metric belongs to. This ensures that unexpected spikes are not missed. I'm not sure what top is doing in this same case. It may be ignoring spikes and simply displaying an average. Brad ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Ganglia-general mailing list Ganglia-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ganglia-general
