This role installs the Memcached memory object caching system in the latest version provided by NixOS.


Out of the box, Memcached is set up with a couple of common default parameters and listens on localhost and the IP-addresses of the ethsrv-interface of your VM (See Networking for details on this topic).

If you need to change the behaviour of Memcached, you have to put the changed options into a JSON file and save it to /etc/local/memcached/memcached.json.

For further information on how to activate changes on our NixOS-environment, please consult section Local Configuration.

Supported options are:

  • port: The port memcached should listen on. Default: 11211

  • maxMemory: The maximum amount of memory to use for storage in MB. Default: 64

  • maxConnections: The maximum amount of simultaneous connections. Default: 1024

  • extraOptions: A string containing any additional command line options you like Memcached to be started with. For reference consult Memcached’s man page.

So a basic non-default configuration might look like:

  "port": "11211",
  "maxMemory": "256",
  "maxConnections": "2048"