I'm developing a module that uses a handler module and header+body filter module
at my handler phase (registered in the nginx rewrite phase) i stop the request (return NGX_OK), then issue a subrequest to another server, get the result back (hook function), then continue to the header+body filter, change the headers + body and calls the next filters accordingly.
also, the subrequest runs thru a proxy , here's the relevant conf lines:
----------------------------------
(general:)
keepalive_timeout 65;
gzip on;
proxy_http_version 1.1;
worker_connections 1024;

location / { // this location is where the ab tries to get (see below the ab test)
include <my module conf>
proxy_pass http://server
}

location /def1 { // this is the subrequest uri
proxy_buffers 8 128k;
proxy_buffer_size 128k;
proxy_busy_buffers_size 128k;

proxy_pass http://server2/page.php // another nginx runs fastcgi
}
------------------------------------------

all works fine, untill i run an "ab" test against my nginx (10/12 workers) that runs on a multi-core, heavy duty linux server, and here's my ab line:
ab -c 50 -n 20000 http://...myserver...
the actual rate is ~1000 requests per second, very high...

but almost exactly after 18500-18600 reuests (that ran smoothly without any errors, debug level INFO with printouts of my own) - the nginx hangs - not stuck - since i see in debug level "debug" its epoll loop runing ok, but not recv nor proceesing any other requests although they continue to come from my ab test

any suggestions please ?

thanks

Gad