Re: Weird MRTG Graphs

Responsible@g-net.be said:
> I've included graphs for HIT-SVC (HIT Average Service Time) and REQ (#
> REQUESTS / MINUTE) Should I worry about "the spikes" in the HIT-SVC
> graphs ... this is normally rather low (between 10ms en 50ms) but
> "spikes" sometimes to 1500ms or more ;-) The funny thing is that this
> happens during "night time" when the #requests is very,very low ...
> During daytime I get peaks of about 520requests/minute and then the
> response times are very good (average 20ms - 50ms) for my site...

It is a statistical problem, I think.
Consider: during the day, you have many people requesting small (a few KB)
files that are quickly served, and a few people requesting large (tens of MB)
files which take a long time to be served. But because there are many accesses,
the long time for serving the big files is lost in the average.

during day: (1000*10ms+3*100s)/1003 = 310/1003 = 0.309

During night, you only have a few people requesting small files. Now somebody
comes figuring he will download communicator_4.07 during the night when
phone calls are cheap:

(10*10ms+1*100s)/11 = 100.1/11 = 9.1

Disclaimer: Numbers used are merely symbolic and intend to give you the idea,
not simulate real data.

Hope this helps.
Best regards,
       Matija Grabnar

-- 
"My name is Not Important. Not to friends. 
    But you can call me mr. Important"  - Not J. Important 
Matija.Grabnar@arnes.si