zookeeper-queue

node-zookeeper-queue

FIFO queue using ZooKeeper, implemented with node.js streams

Download

The source is available for download from GitHub. Alternatively, you can install using Node Package Manager (npm):

npm install zookeeper-queue

Quick Example

This library exports two different stream constructors, depending on whether you want publish or subscribe (write or read). Both streams follow the standard stream interface for Writable or Readable with the addition of a destroy() method on SubQueue to disconnect from ZooKeeper, which is done with the end() method on PubQueue.

var zkQueue = require('zookeeper-queue');
var ZKPubQueue = zkQueue.PubQueue; // Inherits from streams.Writable
var ZKSubQueue = zkQueue.SubQueue; // Inherits from streams.Readable
 
var options = { path: '/myqueue', host: 'localhost', port: 2181 };
 
var subQueue = ZKSubQueue(options)
  .on('connect', function() {
    console.log('[SUB] Connected');
  })
  .on('data', function(data) {
    console.log('[SUB] Received a message: ' + data.toString());
 
    pubQueue.end();
    subQueue.destroy();
  })
  .on('close', function() {
    console.log('[SUB] Closed the queue connection');
  });
 
var pubQueue = new ZKPubQueue(options)
  .on('error', function(err) {
    console.error('[PUB] An error occurred: ' + err);
  })
  .on('connect', function() {
    console.log('[PUB] Connected. Writing "hello world" to the queue');
    pubQueue.write('hello world');
  })
  .on('close', function() {
    console.log('[PUB] Closed the queue connection');
  });