[rrd-developers] two problem about RRD UPDATE

[Tobias Oetiker]

Today lily wrote:

> Hello everyone :
>
>     Recently I use the rrdtool to create about 12 thousand rrd-file, and
> update them in 30s . RRDtools version is 1.2.27 and the OS is Linux - 2.6.9.
> The disk is Raid 10 , and the FS is ext2
>     I have encountered tow problem :
>
>     The first one is the   performance problem. I read the 'Tuning RRDtool
> for performance', and do the vm Optimizations. But it seems not work. The IO
> await list is sometime very high.
>        Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s
> wkB/s avgrq-sz avgqu-sz   await  svctm  %util
>       cciss/c0d0   0.00   0.00  0.00 112.44    0.00  907.77     0.00
> 453.89     8.07   112.99 1001.39   9.23 103.73
>     It can't update 12 thousand file in 30s. How can I improve its
> performance ???

the problem could be your kernel version, the implementation of
posix fadvise has seen quite some changes.

>     The second is sometime when I update the files , there is an error :
>          illegal attempt to update using time 1236857494 when last update
> time is 1236857494 (minimum one second step)
>      but I use the timestamp is 1236886011, not the 1236857494. And I use
> the rrdtool last to see the last update time of the file , I find the last
> update time is 1236857468, also not 1236857494. I have debug a lot of time ,
> but have no idea about it .
>    I want to know  is anyone encountered this problem ? Or know the solution

I have never seen this problem ...

cheers
tobi

>
>
>    Thank you  !
>
>
>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900