Class: PrometheusExporter::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/prometheus_exporter/client.rb

Defined Under Namespace

Classes: RemoteMetric

Constant Summary collapse

MAX_SOCKET_AGE = 
25
MAX_QUEUE_SIZE = 
10_000

Instance Method Summary collapse

Constructor Details

#initialize(host:, port:, max_queue_size: nil, thread_sleep: 0.5) ⇒ Client

Returns a new instance of Client.



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# File 'lib/prometheus_exporter/client.rb', line 31

def initialize(host:, port:, max_queue_size: nil, thread_sleep: 0.5)
  @metrics = []

  @queue = Queue.new
  @socket = nil
  @socket_started = nil

  max_queue_size ||= MAX_QUEUE_SIZE
  max_queue_size = max_queue_size.to_i

  if max_queue_size.to_i <= 0
    raise ArgumentError, "max_queue_size must be larger than 0"
  end

  @max_queue_size = max_queue_size
  @host = host
  @port = port
  @worker_thread = nil
  @mutex = Mutex.new
  @thread_sleep = thread_sleep
end

Instance Method Details

#process_queue ⇒ Object 



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# File 'lib/prometheus_exporter/client.rb', line 69

def process_queue
  while @queue.length > 0
    ensure_socket!

    begin
      message = @queue.pop
      @socket.write(message.bytesize.to_s(16).upcase)
      @socket.write("\r\n")
      @socket.write(message)
      @socket.write("\r\n")
    rescue => e
      STDERR.puts "Prometheus Exporter is dropping a message: #{e}"
      @socket = nil
      raise
    end
  end
end

#register(type, name, help) ⇒ Object 



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# File 'lib/prometheus_exporter/client.rb', line 53

def register(type, name, help)
  metric = RemoteMetric.new(type: type, name: name, help: help, client: self)
  @metrics << metric
  metric
end

#send(obj) ⇒ Object 



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# File 'lib/prometheus_exporter/client.rb', line 59

def send(obj)
  @queue << obj.to_json
  if @queue.length > @max_queue_size
    STDERR.puts "Prometheus Exporter client is dropping message cause queue is full"
    @queue.pop
  end

  ensure_worker_thread!
end

#stop ⇒ Object 



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# File 'lib/prometheus_exporter/client.rb', line 87

def stop
  @mutex.synchronize do
    @worker_thread&.kill
    while @worker_thread.alive?
      sleep 0.001
    end
    @worker_thread = nil
  end

  close_socket!
end