The Test
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This is an endurance test for a two-router network using ApacheBench and NGINX. ApacheBench makes HTTP requests for 1-megabyte images (through its router's TCP Listener). On the other end of the two-router chain, NGINX serves the images.

The network looks like this:

   ApacheBench — Router_1 — Router_2 — NGINX

ApacheBench allows different levels of 'concurrency' to be used. It is not multi-threaded. If the user requests a concurrency level of N, it just sends N requests one after the other, and then waits for all the responses.

If they do not all arrive within 30 seconds (by default), the test times out.

The Bug
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I ran a test in which ApacheBench, using a concurrency level of 10, requested 1 million images of 1 mb each through the two-router network. None of the five tests ran to completion.  All of them ended with a message similar to this:

  apr_pollset_poll: The timeout specified has expired (70007)
  Total of 242500 requests completed

When I ran the same test, except with no routers in between ApacheBench and NGINX, all five iterations ran to completion.

The Code
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I used Main code on both the Router and Proton as of a few days ago.

The Setup
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The two router configuration files are attached.
Also attached is my config file for NGINX, which I put in /etc/nginx/nginx.conf

The image that got served was at:  /var/www/html/images/launch_1M.tif

And the ApacheBench command that I used was:

  ab -n 1000000 -c 10 http://localhost:5801/images/launch_1M.tif

For the version of the test with no routers involved, the ApacheBench command is:

  ab -n 1000000 -c 10 http://localhost/images/launch_1M.tif

By the way, the image that I used was of a rocket launch.
I have no idea what might happen if you show it an image of a rocket exploding!