Re: [libmicrohttpd] Problem with Keep-Alive and MHD_OPTION_CONNECTION_TIMEOUT in MHD_USE_THREAD_PER_CONNECTION mode

[Christian Grothoff]

Hi!

I tried your script on my system, with keep-alive, and I get 0.01%
errors (throughput: 5395.7/sec, 860.2 kb/s for 15000 samples).

If I change the code to add the "close" header, I get 0.13% errors,
3425/sec throughput, and 535kb/s, which I'd say is expected.

So this seems to be (again) a W32-specific issue :-(.

-Christian

On 12/06/2015 11:46 PM, silvioprog wrote:
> Hello bro,
> 
> Yes, it killed the problem definitively! 3:)
> 
> I did many tests using different machines and now it works like a charm,
> thanks a lot for this fix.
> 
> However ( ^^' ), I saw a small problem, but it is related only to the
> keep-alive feature, even using previous versions like 0.9.46: when I use
> keep-alive, I get many errors in many requests. When I disable the
> keep-alive, I get only some errors. It is very easy to be reproduced, but
> you need to use some tool like JMeter. Let's go to see that:
> 
> . get JMeter here [1] and execute its jar file (on Windows, I just double
> click in the `ApacheJMeter.jar` file);
> . get this jmx file[2] file and open it in the JMeter (if you prefer, I can
> explain you what I used in this test);
> . expand the "Thread Group" hree, select the "Aggregate Report" options,
> and click the `Start` button after compile and run this[3] example.
> 
> In my machine, when I kept the line [4] commented (ie, using keep-alive),
> the result was:
> 
> Samples: 15000
> 95% line: 75
> *Error: 51,52%*
> 
> But, when I uncommented this line (ie, using connection close instead of
> keep-alive) and retested it, the result was:
> 
> Samples: 15000
> 95% line: 572 // yes, it's OK for `connection: close`
> *Error: 0,56%*
> 
> In short: using keep-alive you get ~51,52% errors and connection close only
> 0,56%. It is a little bit strange, because I did some tests using other
> servers (NodeJS, Jetty and Nginx) and it works fine, 0,0% erros. :-/
> 
> [1]
> http://mirror.nbtelecom.com.br/apache//jmeter/binaries/apache-jmeter-2.13.zip
> [2] https://www.dropbox.com/s/wiu5gtsflj8omz0/HTTP%20Request.jmx?dl=1
> [3] http://pastebin.com/3wC5035F
> [4] MHD_add_response_header(response, MHD_HTTP_HEADER_CONNECTION, "close")
> 
> On Sat, Dec 5, 2015 at 1:33 PM, Christian Grothoff <address@hidden>
> wrote:
> 
>> Hi!
>>
>> Reading the code I noticed an #ifdef WINDOWS'ed call to shutdown() that
>> would only be executed (in your particular setting) whenever yet another
>> connection was accepted, possibly delaying the TCP connection tear down.
>> I've tried to move the respective logic to happen earlier in SVN 36731.
>>  Please try this version, and let me know if this fixes your problem.
>> (Again, the problem doesn't really hit me on GNU/Linux, so this may or
>> may not be related.)
>>
>> Happy hacking!
>>
>> Christian
> 
>

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