zk

Zookeeper client library for Node

Zk

Zk is a promised based Zookeeper client library for Node. It uses the fork of C binding from node-zookeeper and makes it easier to use.

The following methods are implemented:

  • get
  • set
  • create
  • exists
  • delete
  • getChildren
  • getChildren2
$ npm install zk
var Zookeeper = require('zk')
var zk = new Zookeeper()
 
zk.connect().then(function() {
    // zk.create(), zk.set()... 
})
zk.create('/test-node-', 'value', Zookeeper.ZOO_SEQUENCE | Zookeeper.ZOO_EPHEMERAL).then(function(_path) {
    // _path is created node path 
})
return zk.set(path, 'value2', -1).then(function(){
    zk.get(path).then(function(reply){
        // reply.stat is node stat object 
        // reply.data is node value (Buffer) -> reply.data.toString() will be 'value2' 
    })
})

Watches are implemented as promises conditionaly returned with results:

get without watch:

zk.get(path).then(function(reply) {
    // reply.stat is node stats 
    // reply.data is node value (buffer) 
})

get with watch:

return zk.get(path, true).then(function(reply) {
    // reply.stat, reply.data as above 
    // reply.watch is a promise 
    return reply.watch.then(function(event){
        // event.type: 'child' | 'changed' | 'deleted' .. 
        // event.state 
        // event.path 
    })
})

See tests for more

var Zookeeper = require('zk')
var Lock = Zookeeper.Lock
var zk = new Zookeeper()
 
// zk.connect() ... 
 
var lock = new Lock(zk, 'lockName')
 
var promise = lock.lock(function(){
    // we got the lock! 
    // ... do something and return a promise 
})

Function passed to lock() should return a promise. That promise will be the return value of lock() call

License (MIT)

Copyright (c) 2014 Oleksiy Krivoshey.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.