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Re: [hobbit] Re: hobbit_rrd stops working after about 1 hour



Hi Naeem,

I have over 18000 rrd files being updated every 5 minutes, and havent seen any problems with them.
i'm running hobbit on a 2x3Gh compaq server with redhat 3.0



but,
i do have heavy i/o due to hobbitd_rrd, and it is getting a problem for me,
i'm planning to add a array card with 256M of cache in 1 or 2 days to lower the i/o wait..
i have the feeling that hobbitd_rrd could cause performance issue for large site and may not be fully optimized... henrik ?




concerning your problem, i posted this early this month :
"hobbitd just slows down dramaticly, causing bbtest's results transmition to take over 250s instead of 20s;
the rrd files aren't being updated anymore and some requests to cgi's are saying event is not available..
notifications are being sent though and external scripts don't seem to be affected


doing a stop/start of hobbit solved the problem right now."

this happened twice for me; bbtest went yellow, i got called and restarted hobbit..


is everything nice and green for your bigbrother server itself (bbtest,bbgen,hobbitd) ?
have their timing execution really changed before and after the problem ?
do you have any interesting logs ?
are the graphs for the bigbrother server itselft with "holes" ? (or the first server in your bb-hosts file)




--
Olivier Beau


Le 22 août 05 à 21:28, Naeem.Maqsud (at) sybase.com a écrit :

Well, as nobody has suggested anything to my problem I guess that I'm the
only one having this issue. I have managed to find the root cause. The
hobbitd_rrd process was showing to be in "uninterruptible sleep" state most
of the time with high iowait associated with the CPU it was running on. I
suspected that the problem may be due to disk IO while updating rrds for
the 2000 hosts.
I created a tmpfs filesystem and copied the rrd directory into it. Since
then (48 hours ago) my rrd graphs have been updating continuously. I do
however need to write back to disk periodically to avoid loss of data after
a reboot.


This is OK as a temporary fix but I would like to have a permanent
solution. I would like to hear from other hobbit users who have more than
1000 hosts monitored. What type of servers and disk subsystems are they
using? Perhaps my problem is to do with RedHat and Dell server combination.
Perhaps I need to stripe over multiple spindles.


-Naeem




Naeem
Maqsud/SYBASE
To
08/18/2005 05:02 hobbit (at) hswn.dk
PM cc


Subject
hobbit_rrd stops working after
about 1 hour











Hi,

I'm testing out hobbit 4.1.1 for possible migration from big brother (with
bbgen). I suspected scalability issues with BB as my rrd graphs were
updated intermittently. However, hobbit is exhibiting similar problems.
After about 1 hr of restarting hobbit, the rrd graphs stop updating except
for the cpu utilization for the hobbit server itself.


The hobbit server is running RedHat Linux AS 3.0. It has 2 x 2.4 GHz Xeon
processors and 1GB of memory. About 800 servers are sending updates to the
hobbit server. Another 1200 servers are getting remote tests.


Load average has stayed below 1 most of the time. CPU usage has been low
with 75% idle. 4 CPUs show up due to hyperthreading and I've noticed that
after the restart of hobbit server, hobbitd_rrd process stays on CPU3 with
100% utilization for the one hour that it is busy.


I hope someone can shed some light on this.

Thanks,
Naeem




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