NAME

Net::STOMP::Client::HeartBeat - Heart-beat support for Net::STOMP::Client

SYNOPSIS

  use Net::STOMP::Client;
  $stomp = Net::STOMP::Client->new(host => "127.0.0.1", port => 61613);
  ...
  # can set the desired configuration only _before_ connect()
  # the client can send heart-beats every 5 seconds
  $stomp->client_heart_beat(5);
  # the server should send heart-beats every 10 seconds
  $stomp->server_heart_beat(10);
  ...
  $stomp->connect();
  ...
  # can get the negotiated configuration only _after_ connect()
  printf("negotiated heart-beats: client=%.3f server=%.3f\n",
      $stomp->client_heart_beat(), $stomp->server_heart_beat());

DESCRIPTION

This module handles STOMP heart-beat negotiation. It is used internally by Net::STOMP::Client and should not be directly used elsewhere.

METHODS

This module provides the following methods to Net::STOMP::Client:

client_heart_beat([VALUE]): get/set the client heart-beat
server_heart_beat([VALUE]): get/set the server heart-beat
last_received(): get the time at which data was last received, i.e. read from the network socket
last_sent(): get the time at which data was last sent, i.e. written to the network socket
beat([OPTIONS]): send a NOOP frame (using the noop() method) unless the last sent time is recent enough with regard to the client heart-beat settings

For consistency with other Perl modules (for instance Time::HiRes), time is always expressed as a fractional number of seconds.

HEART-BEATING

Starting with STOMP 1.1, each end of a STOMP connection can check if the other end is alive via heart-beating.

In order to use heart-beating (which is disabled by default), the client must specify what it wants before sending the "CONNECT" frame. This can be done using the "client_heart_beat" and "server_heart_beat" options of the new() method or, this is equivalent, the client_heart_beat() and server_heart_beat() methods on the Net::STOMP::Client object.

After having received the "CONNECTED" frame, the client_heart_beat() and server_heart_beat() methods can be used to get the negotiated values.

To prove that it is alive, the client just needs to call the beat() method when convenient.

To check if the server is alive, the client just needs to compare the current time and what is returned by the last_received() and server_heart_beat() methods. For instance:

  $delta = $stomp->server_heart_beat();
  if ($delta) {
      $inactivity = Time::HiRes::time() - $stomp->last_received();
      printf("server looks dead!\n") if $inactivity > $delta;
  }

AUTHOR