roger v3.2.1

View Source Configuration

amqp-connection

 AMQP connection

Roger depends on RabbitMQ as its backing store. The minimum configuration is below:

config :roger,
  amqp: [
    host: "localhost",
    port: 5672
  ]

These options are directly forwarded to the AMQP connection. The most common options are:

  • :username - The name of a user registered with the broker (defaults to "guest");
  • :password - The password of user (defaults to "guest");
  • :virtual_host - The name of a virtual host in the broker (defaults to "/");
  • :host - The hostname of the broker (defaults to "localhost");
  • :port - The port the broker is listening on (defaults to 5672);
  • :channel_max - The channel_max handshake parameter (defaults to 0);
  • :frame_max - The frame_max handshake parameter (defaults to 0);
  • :heartbeat - The hearbeat interval in seconds (defaults to 0 - turned off);
  • :connection_timeout - The connection timeout in milliseconds (defaults to infinity);
  • :ssl_options - Enable SSL by setting the location to cert files (defaults to none);
  • :client_properties - A list of extra client properties to be sent to the server, defaults to [];

worker-callbacks

 Worker callbacks

Roger can be configured with a callback module which invoke functions on various places in a job's life cycle.

config :roger,
  callbacks: MyWorkerModule

In this scenario, MyWorkerModule needs to use Roger.Worker.Callback:

defmodule MyWorkerModule do
  use Roger.Partition.Worker.Callback

  def after_run(_app_id, job, result, _state) do
    IO.puts("Job #{job.id} succeeded with: #{inspect result}")
  end
end

In this worker module, you can implement the functions before_run/2, after_run/4, on_error/4, on_cancel/2 and on_buried/4 to respond to job events.

See Roger.Partition.Worker.Callback for the full documentation on these functions.

state-persistence-callbacks

 State persistence callbacks

Each Roger partition has one global process running in the cluster, which holds some information necessary to implement certain features (see Roger.Partition.Global for details).

It provides hooks to persist the information between partition / node restarts. By default, the global state is loaded from and written to the filesystem, but it is possible to override the persister, like this:

config :roger,
  persister: Your.PersisterModule

The persister module must implement the Roger.Partition.Global.StatePersister behaviour, which provides simple load and save functions.