[99s-extend] Cowboy HTTPS connection memory usage

[Loïc Hoguin]

Can you try enabling eprof to see where the VM spends its time?

On 12/21/2012 05:49 PM, rambocoder wrote:
> In my preliminary testing, I used Jmeter this morning since it's an
> easy GUI load testing app and this is what I am seeing:
>
> With R15B03-01 [smp:4:4] [async-threads:4] [hipe] [kernel-poll:true],
> when I establish 1K concurrent connections via HTTPS, each connection
> takes up about 68K of memory.
>
> Unfortunately, after about 1050-1200 connections, on my test server the
> Erlang scheduler jumps to 100% CPU utilization on all 4 schedulers,
> while up to that point the scheduler's load was oscillating up and down.
> Using the Observer, there is only 1 ssl_connection_sup  in the ssl
> application, having to deal with 1000+ gen_fsm workers, so that might be
> the bottleneck. Since the ulimit on my server is 50000 I don't think I
> am hitting any type of file handler's limit.
>
> Loïc and the group, am I missing some setting that is causing the
> scheduler to go to 100% CPU and the run que in observer to be 99?
>
> Sincerely,
>
> rambocoder
>
>
>
> On Fri, Dec 21, 2012 at 6:45 AM, Loïc Hoguin <essen at ninenines.eu
> <mailto:essen at ninenines.eu>> wrote:
>
>     On 12/21/2012 04:34 AM, rambocoder wrote:
>
>         Does anybody know either from benchmarks or real world data what
>         is the
>         average memory footprint of each concurrent HTTPS connection to
>         cowboy?
>
>
>     I don't have anything, sorry. I'm guessing it consumes a lot more
>     than TCP though.
>
>
>         SSL app in Erlang reuses SSL session-ids so I am not sure if the
>         Apache
>         Bench I test with reuses the session id or it does not.
>
>
>     I wouldn't know, but I wouldn't trust Apache Bench doing the right
>     thing. Any other benchmark tool usually works better in my experience.
>
>
>         BTW, what makes an erlang api "documented" vs "undocumented". For
>         example ssl:session_info/1 function here (
>         https://github.com/erlang/otp/__blob/maint/lib/ssl/src/ssl.__erl#L411
>         <https://github.com/erlang/otp/blob/maint/lib/ssl/src/ssl.erl#L411>
>         ) has
>         a spec and a short doc, but session_info is not described
>         http://www.erlang.org/doc/man/__ssl.html
>         <http://www.erlang.org/doc/man/ssl.html> .ssl:session_info/1 is
>         a useful
>         function to be able to track if the load generator is reusing
>         the SSL
>         session_id or it is generating new one, because that would make
>         all the
>         difference during measurement due to Erlang caching SSL sessions
>         by default.
>
>
>     The documentation is separate (they're not using edoc). It's perhaps
>     not deemed useful enough for documenting it. I wouldn't worry about
>     using it for measurements though.
>
>     Try asking Ingela on the ML about it, perhaps they just forgot to
>     document it.
>
>     --
>     Loďc Hoguin
>     Erlang Cowboy
>     Nine Nines
>     http://ninenines.eu
>
>
>
>
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-- 
Loïc Hoguin
Erlang Cowboy
Nine Nines
http://ninenines.eu