Adrestia

Run

In order to test with big loads, increase open file limits.

Open file: /etc/security/limits.conf and paste following towards end:

*         hard    nofile      500000
*         soft    nofile      500000
root      hard    nofile      500000
root      soft    nofile      500000

Once you save file, you may need to logout and login again.

Download all dependences with mix deps.get.

Spin up as many dummy servers as you like with ruby test_server -p $PORT and then add them to your config.exs file.

Upon configuring all up (via config.exs), run mix adrestia.balance.

Actors

A Plug-based Cowboy server handles all new connections, using Endpoint as a plug, which interacts with Balancer, asking for a server address to derive the request.

The main pipeline can be seen in Endpoint, line 18. The cacheability is determined upon entering the pipeline, which can skin cache related steps if neccesary.

If there are no available servers, the request skips the pipeline and is dispatched with service_unavailable to the sender.

Every active_check_time all endpoints are queried with a HEAD request, and reported it's status to Balancer. Also the results are printed.

ActiveCheck is not an Actor and is handled by Erlang's :timer library.

Cowboy <-- call --> Endpoint <-- server_address --> Balancer <-- server_up / server-down--> ActiveCheck

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