Red Hat Bugzilla – Bug 470286
Schedd stats graph drawing off right hand side
Last modified: 2015-11-15 19:05:55 EST
The stats graph for a schedd coming from north-15 is drawing off the right hand side of the graph.
Theory is this is an issue with north-15's clock. However, if true, such an issue would be a nightmare to debug by a customer, so some means to handle clock skew should be implemented.
north-15 was sending stats with a future time (relative to the machine cumin is running on).
Solution implemented: If the recTime sent in the update message is in the future, use the current time instead.
because of which I can not access any shedulers and see
the graphs on rev 2751.
But nevertheless, I have reproduced the bug on rev 3002:
0. turn off NTP, set time 20 mins back on local machine
running cumin (via 'date' command)
1. clearly install cumin, including database init
2. log in, add north-15.lab.bos as a broker
3. Grid -> Schedulers -> <one_scheduler>
Maybe it is not the same as when it continuously started at
(as I understand it) non-visible right-hand side, but the
graphing when the time is not in-sync is definitely strange
in rev 3002. See the attached picture - for at least 5 minutes,
there was no line and suddenly it appeared for the alredy
passed time. And then, when I refreshed the page 5 more minutes
later, the weakly-colored-block moved to right and was not
continuous (still the same length); all repeating. Kind of:
... and so on and so forth ...
Created attachment 327084 [details]
The moving non-continuous bars (on both graphs).
Here is cropped screenshot.
I think this is explained by this defect:
The charts only draw segments for data points on the graph.
10 mins 0 mins
o | o----------o |
A B C
Since point A is off the end, no A-B segment is drawn. I think we should try to address this in 1.1.1.
Addressed in revision 3046. I'm querying 1.5 x period seconds, and then bailing out after I get the first sample outside the period window.
Wonderful! Works as I expect it to.
Verified on RHEL5.3 i386, cumin-0.1.3073-1.el5
I am considering the original time-not-in-sync issue
solved as well and much earlier as there was no off-graph
drawing already in rev 3002.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.