Class: Seekmodo::Sdk::AutoPromoter

Inherits:
Object
  • Object
show all
Defined in:
lib/seekmodo/sdk/auto_promoter.rb

Constant Summary collapse

STATE_KEY = 
"numinix.seekmodo.fsm_state"
DEFAULT_PROMOTE_AFTER_SECONDS = 
3600
DEFAULT_DEMOTE_COOLDOWN_SECONDS = 
900

Instance Method Summary collapse

Constructor Details

#initialize(snapshot, breaker, cache, promote_after_seconds: DEFAULT_PROMOTE_AFTER_SECONDS, demote_cooldown_seconds: DEFAULT_DEMOTE_COOLDOWN_SECONDS, clock: nil) ⇒ AutoPromoter

Returns a new instance of AutoPromoter.



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# File 'lib/seekmodo/sdk/auto_promoter.rb', line 15

def initialize(
  snapshot,
  breaker,
  cache,
  promote_after_seconds: DEFAULT_PROMOTE_AFTER_SECONDS,
  demote_cooldown_seconds: DEFAULT_DEMOTE_COOLDOWN_SECONDS,
  clock: nil
)
  @snapshot = snapshot
  @breaker = breaker
  @cache = cache
  @promote_after_seconds = promote_after_seconds
  @demote_cooldown_seconds = demote_cooldown_seconds
  @clock = clock || -> { Time.now.to_i }
end

Instance Method Details

#current_state ⇒ Object 



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# File 'lib/seekmodo/sdk/auto_promoter.rb', line 73

def current_state
  load_state
end

#tick ⇒ Object 



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# File 'lib/seekmodo/sdk/auto_promoter.rb', line 31

def tick
  config = @snapshot.get
  configured_mode = config.fetch("mode", Mode::OFF).to_s
  auto_promote = config.fetch("auto_promote", true)

  if configured_mode != Mode::ACTIVE
    return result(Mode::OFF, Mode::OFF, "held", "mode is not active; auto-promoter idle")
  end
  unless auto_promote
    return result(Mode::OFF, Mode::OFF, "held", "auto_promote disabled")
  end

  state = load_state
  current = state["current_state"].to_s
  now = @clock.call
  breaker_snapshot = @breaker.snapshot
  breaker_open = breaker_snapshot["state"] == CircuitBreaker::STATE_OPEN

  if breaker_open && current == Mode::ENFORCE
    if now - state["last_transition_at"].to_i < @demote_cooldown_seconds
      return result(current, current, "held", "demote cooldown active")
    end
    write_state(Mode::SHADOW, now)
    return result(current, Mode::SHADOW, "demoted", "breaker open at enforce")
  end

  settled_for = now - state["last_transition_at"].to_i
  if breaker_open
    return result(current, current, "held", "breaker open")
  end
  if settled_for < @promote_after_seconds
    return result(current, current, "held", "settled for #{settled_for}s, need #{@promote_after_seconds}s")
  end

  next_step = next_step_up(current)
  if next_step == current
    return result(current, current, "held", "already at enforce")
  end
  write_state(next_step, now)
  result(current, next_step, "promoted", "breaker closed, settled")
end