Olivier,
Why don't you try the approach of putting your rrd files in a tmpfs
filesystem? This seems to have resolved my rrd problem. At least you can
try to see if this resolves your issue and then you know for sure it is
related to disk IO. This is what I did:
1. mkdir /usr/local/bbvar/rrd_orig
2. mv /usr/local/bbvar/rrd /usr/local/bbvar/rrd_orig
3. mkdir /usr/local/bbvar/rrd
4. Add the following line to /etc/fstab:
tmpfs /usr/local/bbvar/rrd tmpfs mode=755,rw,size=2G 0 0
5. mount /usr/local/bbvar/rrd; chown <id of bb user> /usr/local/bbvar/rrd
6. cp -pr /usr/local/bbvar/rrd_orig/rrd/* /usr/local/bbvar/rrd
7. Start hobbit
If you want to keep this as a permanent solution, then you will need to
setup a cronjob to periodically copy the rrd files from the tmpfs
filesystem back to disk. This is because if you unmount the tmpfs FS all
data will be lost. You can put a line in crontab as shown below to run at
8:30 PM daily:
30 20 * * * rsync -av /usr/local/bbvar/rrd /usr/local/bbvar/rrd_orig
Remember that everytime you reboot, you will need to copy the files from
disk to the tmpfs filesystem. You can put a line in /etc/rc.local to do
this for you.
Hope this helps.
-Naeem
Olivier Beau
<olivier at qalpit.c
om> To
user-ae9b8668bcde@xymon.invalid
08/22/2005 11:28 cc
PM
Subject
Re: [hobbit] Re: hobbit_rrd stops
Please respond to working after about 1 hour
user-ae9b8668bcde@xymon.invalid
Hi,
it happened a third time for me this night (3 times in 3 weeks) :
syptoms: hobbitd seems to slow down and stops graphing.
i think Naeem and me are hitting a bug.
i've looked closer this night, and i saw that hobbitd_rrd was running at
100% on
the cpu it was on;
i tried to strace the procees, but strace wouldnt give me any ouptut !
i finally killed hobbitd_rrd, and everything went back to normal.
hobbitd.log has : Task rrdstatus terminated, status 1
rrd_status.log has : Worker process died with exit code 1, terminating
during normal running, vmstat shows a i/o wait of 25%
my problems happened always at night, exactly at the time legato starts
-> something strange is happening whith hobbitd_rrd when the server is
under
very heavy i/o..
henrik, could this be a OS issue or more a hobbitd_rrd problem ?
Olivier
Selon user-04efa50aa241@xymon.invalid:
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 user-ae9b8668bcde@xymon.invalid
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
--
Olivier Beau