/Ruby on Rails 5.1

class ActionCable::Server::Base

Included modules:

A singleton ActionCable::Server instance is available via ActionCable.server. It's used by the Rack process that starts the Action Cable server, but is also used by the user to reach the RemoteConnections object, which is used for finding and disconnecting connections across all servers.

Also, this is the server instance used for broadcasting. See Broadcasting for more information.



Public Class Methods

logger() Show source
# File actioncable/lib/action_cable/server/base.rb, line 15
def self.logger; config.logger; end
new() Show source
# File actioncable/lib/action_cable/server/base.rb, line 20
def initialize
  @mutex = Monitor.new
  @remote_connections = @event_loop = @worker_pool = @pubsub = nil

Public Instance Methods

call(env) Show source

Called by Rack to setup the server.

# File actioncable/lib/action_cable/server/base.rb, line 26
def call(env)
  config.connection_class.call.new(self, env).process
connection_identifiers() Show source

All of the identifiers applied to the connection class associated with this server.

# File actioncable/lib/action_cable/server/base.rb, line 80
def connection_identifiers
disconnect(identifiers) Show source

Disconnect all the connections identified by `identifiers` on this server or any others via RemoteConnections.

# File actioncable/lib/action_cable/server/base.rb, line 32
def disconnect(identifiers)
event_loop() Show source
# File actioncable/lib/action_cable/server/base.rb, line 55
def event_loop
  @event_loop || @mutex.synchronize { @event_loop ||= ActionCable::Connection::StreamEventLoop.new }
pubsub() Show source

Adapter used for all streams/broadcasting.

# File actioncable/lib/action_cable/server/base.rb, line 75
def pubsub
  @pubsub || @mutex.synchronize { @pubsub ||= config.pubsub_adapter.new(self) }
remote_connections() Show source

Gateway to RemoteConnections. See that class for details.

# File actioncable/lib/action_cable/server/base.rb, line 51
def remote_connections
  @remote_connections || @mutex.synchronize { @remote_connections ||= RemoteConnections.new(self) }
restart() Show source
# File actioncable/lib/action_cable/server/base.rb, line 36
def restart

  @mutex.synchronize do
    # Shutdown the worker pool
    @worker_pool.halt if @worker_pool
    @worker_pool = nil

    # Shutdown the pub/sub adapter
    @pubsub.shutdown if @pubsub
    @pubsub = nil
worker_pool() Show source

The worker pool is where we run connection callbacks and channel actions. We do as little as possible on the server's main thread. The worker pool is an executor service that's backed by a pool of threads working from a task queue. The thread pool size maxes out at 4 worker threads by default. Tune the size yourself with config.action_cable.worker_pool_size.

Using Active Record, Redis, etc within your channel actions means you'll get a separate connection from each thread in the worker pool. Plan your deployment accordingly: 5 servers each running 5 Puma workers each running an 8-thread worker pool means at least 200 database connections.

Also, ensure that your database connection pool size is as least as large as your worker pool size. Otherwise, workers may oversubscribe the database connection pool and block while they wait for other workers to release their connections. Use a smaller worker pool or a larger database connection pool instead.

# File actioncable/lib/action_cable/server/base.rb, line 70
def worker_pool
  @worker_pool || @mutex.synchronize { @worker_pool ||= ActionCable::Server::Worker.new(max_size: config.worker_pool_size) }

© 2004–2017 David Heinemeier Hansson
Licensed under the MIT License.