Re: [squid-users] squidaio_queue_request: WARNING - Queue congestion

2010/2/17 Henrik Nordström <henrik_at_henriknordstrom.net>:
> tor 2010-02-18 klockan 14:51 +1300 skrev Amos Jeffries:
>
>> Henrik seems to have re-appeared and he has more disk IO experience then
>> me so may have an idea whet to look for ...   ?
>
> My first reaction is to run a small benchmark in parallel to squid
> performing a reasonably slow sequence of random reads over the disks and
> measuring the response time.. SSD disks in particular may have a habit
> of "randomly" block all requests for a while during/after a period of
> writes.. and OS write buffering and batching may even add to this queue
> latency problem.
>
> But I have not read up on the whole problem description.
>
> Also keep in mind that as Amos mentioned earlier these "Queue
> congestion" warnings come more frequently after start as there is a
> filter preventing the logs from getting overwhelmed with this warning.

Thanks Henrik and Amos

I'll do whatever testing is needed. As it's really odd.and I can't use
these servers/disks until I can get this problem identified.

And sorry "sleeping" was just my way of citing the box shows no load,
almost no IO 4-5 when I'm hitting it hard. I do not see this issue
with lesser threads, it's only when I turn up the juice. But with
turning up the connections per second I would expect to see some type
of load and I see none.

and the -X -d I dont see anything but that error, is there another log
file that needs to be enabled vs cache.log and squid.out?

I'll try some various things to see what I can see. I know time dd
tests and bonnie++ and some FIO seem to do just fine. It's only squid
that seems to be having an issue with me or my setup :)

Tory
Received on Thu Feb 18 2010 - 05:40:18 MST