Apologies if this is a trivial question. I have searched it on web and none of the answers have solved my problem. I am trying to read request body and thing seem to work fine if request body is small (4 kb). As soon as it becomes 4+ megabytes,ngx_http_read_client_request_body returns NGX_AGAIN (-2) in rc and my RequestBodyHandler is never called.

snippet of nginx.conf is like this for buffer settings. I have removed lot of other stuff from nginx.conf to keep it brief.

http {
include mime.types;
default_type application/octet-stream;

sendfile on;
keepalive_timeout 65;

client_body_buffer_size 1m;
client_max_body_size 0;
}

/ * code sample start */
r->request_body_in_single_buf = 1;
r->request_body_in_persistent_file = 1;
r->request_body_in_clean_file = 1;
r->request_body_file_log_level = 0;

rc = ngx_http_read_client_request_body(r, RequestBodyHandler);
if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {

CORE_TRACE(Error, L"Nginx read request error: %d", rc);
return from thread.
}

return NGX_DONE.

/ * code sample end */

Just to add some more context here. I use nginx thread pool. So my module's content handler basically queues a task to thread pool. Callback of thread eventually calls ngx_http_read_client_request_body to read request body. If there is an error (as stated in above if condition), thread simply returns and the completion handler of thread is called by nginx. In the completion handler, I do finalize request with NGX_DONE always.