Class: SidekiqQueueStatus::Middleware

Inherits:
Object
  • Object
show all
Defined in:
lib/sidekiq_queue_status/middleware.rb

Constant Summary collapse

DEFAULT_TRESHOLD = 
30
DEFAULT_FAILURE_RATE_PERC = 
10
HEADERS = 
{
  'Content-Type' => 'application/json',
  'Cache-Control' => 'no-cache'
}

Instance Method Summary collapse

Constructor Details

#initialize(app, configured_tresholds, failure_rate) ⇒ Middleware

Returns a new instance of Middleware.



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# File 'lib/sidekiq_queue_status/middleware.rb', line 12

def initialize(app, configured_tresholds, failure_rate)
  @app = app
  @latency_treshold = Hash.new(DEFAULT_TRESHOLD).merge(configured_tresholds)
  @max_failure_rate = failure_rate || DEFAULT_FAILURE_RATE_PERC
end

Instance Method Details

#calculate_failure_rate ⇒ Object 



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# File 'lib/sidekiq_queue_status/middleware.rb', line 39

def calculate_failure_rate
  stats = Sidekiq::Stats::History.new(1)
  processed, failed = [stats.processed, stats.failed].map { |h| h.values.last }
  val = (failed.to_f / processed.to_f) * 100.0
  val > 0 ? val.to_i : 0
end

#call(env) ⇒ Object 



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# File 'lib/sidekiq_queue_status/middleware.rb', line 18

def call(env)
  if env["PATH_INFO"] =~ %r{\A/queue-status\Z}
    errors = []
    queues.each do |name, latency|
      max_latency = @latency_treshold[name]
      errors << "Queue #{name} above threshold of #{max_latency}s" if latency > max_latency
    end
    failure_rate = calculate_failure_rate
    errors << "Failure rate above #{@max_failure_rate}%" if failure_rate > @max_failure_rate
    body = { latencies: queues, failure_percentage: failure_rate, errors: errors }.to_json
    status = errors.any? ? 503 : 200
    [status, HEADERS, [body]]
  else
    @app.call(env)
  end
end

#queues ⇒ Object 



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# File 'lib/sidekiq_queue_status/middleware.rb', line 35

def queues
  Sidekiq::Queue.all.map { |q| [q.name, q.latency.to_i] }.to_h
end