zookeeper

An interface to the Zookeeper distributed configuration server.

License¶ ↑

Copyright 2008 Phillip Pearson, and 2010 Twitter, Inc. Licensed under the MIT License. See the included LICENSE file. Portions copyright 2008-2010 the Apache Software Foundation, licensed under the Apache 2 license, and used with permission.

Install¶ ↑

sudo gem install zookeeper

Usage¶ ↑

Connect to a server:

require 'rubygems'
require 'zookeeper'
z = Zookeeper.new("localhost:2181")

Create, set and read nodes:

z.create("/bacon", "text to be stored in the new node", 0)
data, stat = z.get("/bacon")
  # => ["text to be stored in the new node"...]

z.set("/bacon", "an entirely different line of text", stat.version)
z.set("/bacon", "this won't work", stat.version)
  # CZookeeper::BadVersionError: expected version does not match actual version

data, stat = z.get("/bacon")
  # => ["an entirely different line of text"...]
z.delete("/bacon", stat.version)

Create ephemeral and sequence nodes:

z.create("/parent", "parent node", 0)

z.create("/parent/test-", 
  "an ordered ephemeral node", 
  Zookeeper::EPHEMERAL | Zookeeper::SEQUENCE)
  # => "/parent/test-0"

z.create("/parent/test-", 
  "an ordered ephemeral node", 
  Zookeeper::EPHEMERAL | Zookeeper::SEQUENCE)
  # => "/parent/test-1"

z.get_children(:path => "/")

Idioms¶ ↑

The following methods are initially supported:
  get
  set
  get_children
  stat
  create
  delete
  get_acl
  set_acl

All support async callbacks.  get, get_children and stat support both
watchers and callbacks.

Calls take a dictionary of parameters.  With the exception of set_acl, the
only required parameter is :path.  Each call returns a dictionary with at
minimum two keys :req_id and :rc.