Re: [Erlyaws-list] Yaws concurrency problems

[Steve V. <vi...@ie...>]

On Thu, Mar 24, 2011 at 8:37 AM, Steve Vinoski <vi...@ie...> wrote:
> On Thu, Mar 24, 2011 at 6:14 AM, ALBERT HIDALGO BAREA <ab...@ti...> wrote:
>> Hi,
>>
>> I tested this command and it continues to fail.
>> There is some parameter in Erlang or in Yaws to change/add in order to support a concurrency higher than 300 users?
>
> No, there are no other settings required.
>
> Can you post the details of the errors you're seeing? Also, we need to
> know what version of Erlang you have as well as what version of Yaws
> you have. Are you running on Linux? Meanwhile I'll run some
> experiments on my Linux box.

I've run some experiments and found some interesting results.

On my Ubuntu 10.10 box I have ab version 2.3. No matter what version
of Yaws I used on Erlang/OTP R14B02, ab would die as it neared the end
of the run. If I said run with 20000 concurrent connections and
perform 50000 total requests, it would die saying "connection reset by
peer" after ~47000 or so requests. If I dropped to 2500 concurrent
connections and 5000 total requests, it would work fine. If I tried
2500 and 15000, it would die after ~13000 requests.

I then tried an old version of ab, version 2.0.41-dev running on an
old RHEL4 box. No problems there at all: 20000 concurrent connections
doing 50000 requests or 100000 requests, it all worked fine. 20000
concurrent connections is as high as ab can go, and Yaws handled it,
no problem.

So, you might want to try a testing tool other than ab such as tsung
or httperf, or try to find yourself an older version of ab.

--steve