How to make apache slow and unreliable?

Question

I'm writing some code on a mobile device that uses a REST service to retrieve data from a host. That REST services is being proxied by Apache. In test mode I would like to be able to simulate network outages (as if the device has lost it's cell connection) to test the applications handling of intermittent failures. I also need to validate it's behavior with slow network connections.

I'm currently using Traffic Shaper XP to slow the network connection, but now I need something to make the Apache server send connection resets both randomly and on predefined sequences (to setup and repeat specific test scenarios).

Answer 1

In Apache2 you can make it slow by adjust prefork settings in apache2.conf. The settings below ought to make apache pretty fn slow. They made my local web application take 700% longer to load.

<IfModule mpm_prefork_module>
    StartServers          2
    MinSpareServers       2
    MaxSpareServers      2
    MaxClients          4
    MaxRequestsPerChild   0
</IfModule>

Answer 2

I highly recommend https://github.com/Shopify/toxiproxy from Shopify:

Download https://github.com/Shopify/toxiproxy/releases the cli and server

Run the server:

 ./toxiproxy-server-linux-amd64

On the cli setup proxy to apache on another port e.g. 8080

./toxiproxy-cli create apache -l localhost:8080 -u localhost:80

Make connection slow and unreliable:

./toxiproxy-cli toxic add apache -t latency -a latency=3000 
./toxiproxy-cli toxic add apache -t limit_data -a bytes=1000 --tox=0.01

here add 3 second of latency and stop after 1000 bytes for 1% of requests there are other options for bandwidth etc. You can add or remove these during use. Lots of other features and libraries there.

Answer 3

It looks like DummyNet is the closest thing, but it’s still not quite there. For repeatable testing it would be good to have some control over dropped packets and resets.

Answer 4

Write a little proxy that forwards TCP connections from your app to the apache server and that you can set up in your test to cut the connection after x number of bytes or milliseconds.