Rick Mohr wrote:
On Mon, 23 Jan 2006, Ben Hartshorne wrote:
<snip>
When I go into the page for a single host and click on the 'gmetrics'
link, I find that all of my metrics have a record of being recieved
within the last two minutes (my time period). And yet, their graphs
show up empty.
Any thoughts? What logs should I be looking at?
</snip>
If I am not mistaken, the values shown on the 'gmetrics' page are just
the current values extracted from the XML that is retrieved from the
gmetad process. The graphs however come from rrdtool and are generated
based on the data stored in the round-robin database files.
Is it possible these rrd files are missing some information? I have
never seen it personally, but I suppose a case could arise where gmetad
has accurate current values, but for some reason they are not being put
into the rrd files. You can always use the rrdtool command by hand to
dump out the rrd files for those metrics which appear to have gaps.
Then check to see if the data is actually there.
Also, you could use rrdtool to generate the exact same graph that is
shown on the web page for one of these metrice and dump it straight into
a file. Then you could compare that with the image seen on the web page
(to check for the unlikely event that the generated image if fine, but
the web server is messing something up).
These are just kind of guesses, but maybe one of them will reveal some
info.
Many moons ago (check archives for specifics), I was having this kind of
problem. I noticed that gmetad's RRDs were being updated with the
current date and time, instead of the date and time the metric was
parsed. When gmetad started to lag, two passes on the same metric
within 1 second of each other would cause the *second* update attempt to
bomb out of the second librrd update call, which would abort that entire
iteration of gmetad's update_rrds() loop before it had finished. This
would cause some of the RRD files to have gaps while others did not.
Man, that was a long time ago. I recall putting a lot of snarky debug
code in at around that time trying to fix the problem.
Running gmetad in the foreground with a very high debug level may offer
additional clues. Also, keep an eye on the modification times on the
RRD files that are gapping.
Hope that helps...
