Configuration - lifechurch/subserver GitHub Wiki

Subserver can be configured in a number of ways to best support your system.

Queues

When starting the subserver process with bundle exec subserver subserver will start with the default queue. This means that any Subscriber that does not specify which queue it belongs to will be loaded by this instance of Subserver. Breaking your subscribers into queues allows you to control the horizontal scaling by running multiple subserver processes.

For Example

Run subserver using

bundle exec subserver -q 'critical'
bundle exec subserver -q 'low' -q 'default'

And provide the queue in your subscriber class

class MyImportantSubscriber
  include Subserver::Subscriber
  subserver_options subscription: 'important-messages', queue: 'critital'
end

class MyImportantSubscriber
  include Subserver::Subscriber
  subserver_options subscription: 'regular-messages', queue: 'low'
end

This allows you to independently scale your critical messages based on load.

Subscriber Config

When Subserver starts a listener thread for Pub/Sub it allows configuration of the underlying Pub/Sub subscriber.

class MySubscriber
  include Subserver::Subscriber
  subserver_options { 
    subscription: 'my-subscription', 
    deadline: 60,
    streams: 2, 
    threads: {
      callback: 4,
      push: 2
    },
    inventory: 1000 
  }

Avalible Subscriber Options:

Option	Type	Description
subscription	string Required: True	The name of the Pub/Sub topic subscription.
deadline	numeric Required: false Default: 60	The number of seconds the listener will wait for message acknowlagement.
streams	numberic Required: false Default: 2	The number of recieveing streams for this subscription.
threads	hash Required: false Default: {callback: 4, push: 2}	The number of threads for recieveing messages and pushing acknowlagement.
inventory	numeric Required: false Default: 1000	The number of received messages the subscriber will hold in memory.
queue	string Required: false Default: 'default	The queue that the Subscriber should be loaded on.