[libmicrohttpd] questions on performance

[Taehwan Weon]

Hi,

I made a caching proxy based on libmicrohttpd 0.9.27
While doing a stress test with tsung, I got a strange problem.

My daemon start params were
1) MHD_USE_SELECT_INTERNALLY with # of thread = 40
2) MHD_USE_POLL|MHD_USE_THREAD_PER_CONNECTION

My stress tool(tsung) is generating 10,000 GET requests/sec for 1,000
1KB objects with protocol of HTTP 1.1
HTTP 1.1 Keep-alive feature was off ('cause tsung does not support)

My measurement is between the time when the first request bytes and
the time when completion notification callback signaled.
I subtracted the internal processing time (file-IOs)

Please look at the following values (measured for 2-hours)
1. elapsed time between the time request handler called and time time
completion notification called back. : about 900~1100 msec/req
2. internal file-io(cache-based) operation time : 3 msec/req (all
objects were cached in main memory)
    (to measure file-IO time, I measured the processing time of the
callback given to MHD_create_response_from_callback)

In the 2nd param(MHD_USE_POLL), I found about more than 1,000
libmicrohttpd threads.

Could you please recommend me what I can do for better performance?

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weon