Module: Karafka::Pro::Routing::Features::Swarm::Topic

Defined in:
lib/karafka/pro/routing/features/swarm/topic.rb

Overview

Topic swarm API extensions

Instance Method Summary collapse

Instance Method Details

#active? ⇒ Boolean

Returns should this topic be active. In the context of swarm it is only active when swarm routing setup does not limit nodes on which it should operate.

Returns:

  • (Boolean) —

    should this topic be active. In the context of swarm it is only active when swarm routing setup does not limit nodes on which it should operate



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# File 'lib/karafka/pro/routing/features/swarm/topic.rb', line 84

def active?
  node = Karafka::App.config.swarm.node

  return super unless node

  super && swarm.nodes.include?(node.id)
end

#initialize ⇒ Object

This method calls the parent class initializer and then sets up the extra instance variable to nil. The explicit initialization to nil is included as an optimization for Ruby’s object shapes system, which improves memory layout and access performance.



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# File 'lib/karafka/pro/routing/features/swarm/topic.rb', line 42

def initialize(...)
  super
  @swarm = nil
end

#swarm(nodes: (0...Karafka::App.config.swarm.nodes)) ⇒ Object

Allows defining swarm routing topic settings

Examples:

Assign given topic only to node 1

swarm(nodes: [1])

Assign given topic to nodes from 1 to 3

swarm(nodes: 1..3)

Assign partitions 2 and 3 to node 0 and partitions 0, 1 to node 1

swarm(
  nodes: {
    0 => [2, 3],
    1 => [0, 1]
  }
)

Assign partitions in ranges to nodes

swarm(
  nodes: {
    0 => (0..2),
    1 => (3..5)
  }
)

Parameters:

  • nodes (Range, Array, Hash) (defaults to: (0...Karafka::App.config.swarm.nodes)) —

    range of nodes ids or array with nodes ids for which we should run given topic or hash with nodes expected partition assignments for the direct assignments API.



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# File 'lib/karafka/pro/routing/features/swarm/topic.rb', line 73

def swarm(nodes: (0...Karafka::App.config.swarm.nodes))
  @swarm ||= Config.new(active: true, nodes: nodes)
end

#swarm? ⇒ true

Returns swarm setup is always true. May not be in use but is active.

Returns:

  • (true) —

    swarm setup is always true. May not be in use but is active



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# File 'lib/karafka/pro/routing/features/swarm/topic.rb', line 78

def swarm?
  swarm.active?
end

#to_h ⇒ Hash

Returns topic with all its native configuration options plus swarm.

Returns:

  • (Hash) —

    topic with all its native configuration options plus swarm



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# File 'lib/karafka/pro/routing/features/swarm/topic.rb', line 93

def to_h
  super.merge(
    swarm: swarm.to_h
  ).freeze
end