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

[silvioprog]

Hello, I have good news in the test 2, however in test 3 ...

@Christ, on Linux I got 0.00% erros. MHD is so fast on Linux that I believe that it can support C10K problem. :-)

@Evg, do I need to change the `FD_SETSIZE` and the MHD source before compiling or in the `CMakeLists.txt` of my example?

So, I did more tests after read Evg's messages. Now all results that I'll show uses keep-alive. Test 1:

MHD_start_daemon(

  MHD_USE_THREAD_PER_CONNECTION | MHD_USE_DEBUG, PORT, NULL, NULL,

  &answer_to_connection, NULL,

  MHD_OPTION_END);

40~50% erros. And it returns a lot of `Server reached connection limit (closing inbound connection)` and some `Server reached coServer reached connection limit (closing inbound connection)`, OK, after read this log, I did:

Test 2 (thanks Evgeny):

MHD_start_daemon(MHD_USE_THREAD_PER_CONNECTION | MHD_USE_DEBUG, PORT, NULL, NULL,

  &answer_to_connection, NULL,

  MHD_OPTION_CONNECTION_TIMEOUT, (unsigned int) 240,

  MHD_OPTION_CONNECTION_LIMIT, (unsigned int) 16000,

  MHD_OPTION_END);

Samples: 15000.

0,00% erros.

95% line: 3.

99% line: 5.

OMG, now MHD is so fast! :-o

But, make this small change in your JMeter config:

https://dl.dropboxusercontent.com/u/135304375/snip1.png (I can send a new jmx file if you prefer)

and in the MHD example:

  MHD_OPTION_CONNECTION_LIMIT, (unsigned int) 16000 * 2,

1,84% erros. And a lot of: `Failed to create a thread: Not enough space`. OK, so I disabled the "thread per connection":

MHD_start_daemon(MHD_USE_SELECT_INTERNALLY | MHD_USE_DEBUG, PORT, NULL, NULL,

  &answer_to_connection, NULL,

  MHD_OPTION_CONNECTION_TIMEOUT, (unsigned int) 240,

  MHD_OPTION_CONNECTION_LIMIT, (unsigned int) 16000 * 2,

  MHD_OPTION_END);

Samples: 27255.

Error: 99,61%. LOL

And it locks the last requests.

Sorry for my ignorance, but MHD_USE_SELECT_INTERNALLY should be the more fast MHD option, then or I did something wrong in my test, or this MHD option has a small bug on Windows. :-/

ps. I need to test the `FD_SETSIZE` option, so I'll wait for Evg's answer. :-)

On Mon, Dec 7, 2015 at 4:53 AM, Christian Grothoff <address@hidden> wrote:

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

--

Silvio Clécio