Class: ActionCable::Server::Base
Relationships & Source Files | |
Super Chains via Extension / Inclusion / Inheritance | |
Instance Chain:
self,
Broadcasting
|
|
Inherits: | Object |
Defined in: | actioncable/lib/action_cable/server/base.rb |
Overview
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 ::ActionCable::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.
Class Attribute Summary
- .config rw
Class Method Summary
- .logger
- .new(config: self.class.config) ⇒ Base constructor
Instance Attribute Summary
Instance Method Summary
-
#call(env)
Called by
::Rack
to set up the server. -
#connection_identifiers
All of the identifiers applied to the connection class associated with this server.
-
#disconnect(identifiers)
Disconnect all the connections identified by
identifiers
on this server or any others via::ActionCable::RemoteConnections
. - #event_loop
-
#pubsub
Adapter used for all streams/broadcasting.
-
#remote_connections
Gateway to
::ActionCable::RemoteConnections
. - #restart
-
#worker_pool
The worker pool is where we run connection callbacks and channel actions.
Broadcasting
- Included
#broadcast | Broadcast a hash directly to a named |
#broadcaster_for | Returns a broadcaster for a named |
Constructor Details
.new(config: self.class.config) ⇒ Base
Class Attribute Details
.config (rw)
[ GitHub ]# File 'actioncable/lib/action_cable/server/base.rb', line 17
cattr_accessor :config, instance_accessor: false, default: ActionCable::Server::Configuration.new
Class Method Details
.logger
[ GitHub ]# File 'actioncable/lib/action_cable/server/base.rb', line 21
def self.logger; config.logger; end
Instance Attribute Details
#config (readonly)
[ GitHub ]# File 'actioncable/lib/action_cable/server/base.rb', line 19
attr_reader :config
#logger (readonly)
[ GitHub ]# File 'actioncable/lib/action_cable/server/base.rb', line 22
delegate :logger, to: :config
#mutex (readonly)
[ GitHub ]# File 'actioncable/lib/action_cable/server/base.rb', line 24
attr_reader :mutex
Instance Method Details
#call(env)
Called by ::Rack
to set up the server.
#connection_identifiers
All of the identifiers applied to the connection class associated with this server.
#disconnect(identifiers)
Disconnect all the connections identified by identifiers
on this server or any others via ::ActionCable::RemoteConnections
.
# File 'actioncable/lib/action_cable/server/base.rb', line 40
def disconnect(identifiers) remote_connections.where(identifiers).disconnect end
#event_loop
[ GitHub ]# File 'actioncable/lib/action_cable/server/base.rb', line 65
def event_loop @event_loop || @mutex.synchronize { @event_loop ||= ActionCable::Connection::StreamEventLoop.new } end
#pubsub
Adapter used for all streams/broadcasting.
#remote_connections
Gateway to ::ActionCable::RemoteConnections
. See that class for details.
# File 'actioncable/lib/action_cable/server/base.rb', line 61
def remote_connections @remote_connections || @mutex.synchronize { @remote_connections ||= RemoteConnections.new(self) } end
#restart
[ GitHub ]# File 'actioncable/lib/action_cable/server/base.rb', line 44
def restart connections.each do |connection| connection.close(reason: ActionCable::INTERNAL[:disconnect_reasons][:server_restart]) end @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 end end
#worker_pool
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 80
def worker_pool @worker_pool || @mutex.synchronize { @worker_pool ||= ActionCable::Server::Worker.new(max_size: config.worker_pool_size) } end