Class: Karafka::Swarm::LivenessListener

Inherits:
Object
  • Object
show all
Includes:
Core::Helpers::Time
Defined in:
lib/karafka/swarm/liveness_listener.rb

Overview

Simple listener for swarm nodes that:

- reports once in a while to make sure that supervisor is aware we do not hang
- makes sure we did not become an orphan and if so, exits

Direct Known Subclasses

Pro::Swarm::LivenessListener

Instance Method Summary collapse

Constructor Details

#initialize ⇒ LivenessListener

Returns a new instance of LivenessListener.



16
17
18
19
 
# File 'lib/karafka/swarm/liveness_listener.rb', line 16

def initialize
  @last_checked_at = 0
  @mutex = Mutex.new
end

Instance Method Details

#on_statistics_emitted(_event) ⇒ Object

Since there may be many statistics emitted from multiple listeners, we do not want to write statuses that often. Instead we do it only once in a while which should be enough

While this may provide a small lag in the orphaned detection, it does not really matter as it will be picked up fast enough.

Parameters:

  • _event (Karafka::Core::Monitoring::Event) 


27
28
29
30
31
32
33
 
# File 'lib/karafka/swarm/liveness_listener.rb', line 27

def on_statistics_emitted(_event)
  periodically do
    Kernel.exit!(orphaned_exit_code) if node.orphaned?

    node.healthy
  end
end