Henrik Nordstrom wrote:
On fre, 2008-10-24 at 11:52 -0700, Linda W wrote:
> I see alot of these messages in my squid warning log...
> (count=107) WARNING: Median response time is 57448 milliseconds
This can happen naturally if you at some time have only very few users
and those mostly perform downloads or other long running requests.
But if seen during normal load with mostly interactive browsing requests
then something is wrong.
So it depends on when you got these warnings and how Squid was being
used at the time.
----
Well...definitely, the "huge number of users on this 'squid'" [ME] could
affect that...and, indeed, over the time that log was gathered I know
I've done some multi-megabyte (multi-100MB, maybe a GB or 2) downloads...
BUT---this sure is misleading and confuses the heck out of poor
"ignorami" like me, who think of a response time as something along the lines
of "(srchost)ping -> (->remotehost-echo: "YO!" ->)-> (srchost: "YO!")
I.e. Not a response time for 1 entire request, but a response time for
the smaller and vastly more interactive "sub-packets" that comprise the
data of a larger request.
I.e. -- "I hear/get/grok" what you are saying -- but more useful, for
me, as a real 'warning' would be something that tells me:
"hey, "anal-retentive-response monitor" (that would be me when I'm
looking at these things), I sent a request, and it took 57448 ms, for me
to get back ANY answer from the other end -- even 1 byte..."
You know..like it took 57seconds for the other side to send back anything.
Sure, makes 'Mondo" sense if the time it takes me to download a 1GB image
is greater than 57seconds...that's common sense -- but not something I'm
going to worry about as long as my host<--->host response time is somewhat
in a normal range.
If all of a sudden all of my small(ish) single requests start taking >4 seconds
just get get back __anything__, THEN, I'm thinking -- uhoh---line problems or
something that requires my attention...but long response times when downloading
a large 1G "nature" move (ok, more likely some boring distro image), -- that's
not even something I'd care about seeing.
On the other hand -- a good warning stat -- if I am downloading large 'nature'
images (of distros! what else where you thinking?!) I wouldn't mind a warning
if my _combined_ download rates (through squid) slowed down to some bogus
fraction of my line's capacity.
For example say my line normally can download at 250KBytes/s. If my squid
proxy detected that all download rates combined were only reaching 20KB/s,
that would be something _potentially_ worthy of a log warning message.
But just "long -finish times on a single download"....not so interesting --
especially
if my max-link speed is relatively slow relative to the normal objects I might be
downloading.
I can only see this "warning" getting worse over time, as larger downloads
(images, HD-videos, nature-movies...etc. get longer and higher def, while my DSL
stays stuck in the dark ages (making the "slowskies" (a Turtle family on Comcast
commercials) happy, but....
p.s. nature moves aren't usually my cup-of-tea, but thought I'd mention them as
I know many downloading netizens like nature movies of some particular types or
another.. :-)
Thanks for the clarification....but ... is it possible to provide some other
warning thresholds?
Merci Beaucoup,
Linda
(not that I'm French, but who doesn't like Paris of one sort or another; :-)...yeah
in the sillier than normal mood today, but c'est la vie)
