diff options
Diffstat (limited to 'actioncable/lib/action_cable/server/base.rb')
| -rw-r--r-- | actioncable/lib/action_cable/server/base.rb | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/actioncable/lib/action_cable/server/base.rb b/actioncable/lib/action_cable/server/base.rb index 778f5ffeed..b1a0e11631 100644 --- a/actioncable/lib/action_cable/server/base.rb +++ b/actioncable/lib/action_cable/server/base.rb @@ -52,7 +52,17 @@ module ActionCable @event_loop || @mutex.synchronize { @event_loop ||= config.event_loop_class.new } end - # The thread worker pool for handling all the connection work on this server. Default size is set by config.worker_pool_size. + # 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 db connection pool and block while they wait for other workers to release their connections. Use a smaller worker pool or a larger + # db connection pool instead. def worker_pool @worker_pool || @mutex.synchronize { @worker_pool ||= ActionCable::Server::Worker.new(max_size: config.worker_pool_size) } end |