php 连接zookeeper实例

fengwhen

　　1、安装成功zookeeper后，在zookeeper 的bin目录下有启动相应的启动脚本

　　启动Server
　　./zkServer.sh start

　　启动client：(*注：cli需要安装java）
　　zkCli.sh
　　2、PHP实例：
　　
<?phpclass ZookeeperDemo extends Zookeeper{   public function watcher($i, $type, $key ) {    echo &quot;InsiderWatcher\n&quot; ;     // Watcher gets consumedso we need to set a new one    $this->get( '/test', array ($this, 'watcher' ));  }}$zoo = new ZookeeperDemo( '127.0.0.1:2181' );$zoo->get( '/test', array ($zoo, 'watcher' ));while ( true ){  echo '.' ;  sleep(2);}

leader与worker任务的分配：
class Worker extends Zookeeper{   const CONTAINER= '/cluster' ;   protected $acl = array(                    array (                      'perms' =>Zookeeper:: PERM_ALL,                      'scheme' => 'world' ,                      'id' => 'anyone' ));   private $isLeader = false;   private $znode ;   public function __construct($host = '', $watcher_cb = null ,$recv_timeout = 10000 ) {    parent:: __construct($host, $watcher_cb, $recv_timeout );  }   public function register(){    if(! $this->exists( self ::CONTAINER )) {      $this->create( self ::CONTAINER , null,$this-> acl );    }     $this->znode = $this->create( self ::CONTAINER. '/w-' ,                                  null ,                                  $this->acl,                                  Zookeeper::EPHEMERAL| Zookeeper::SEQUENCE );     $this-> znode =str_replace( self ::CONTAINER .'/' , '' ,$this-> znode );     printf( &quot;I'm registredas: %s\n&quot;, $this-> znode );     $watching = $this->watchPrevious();     if($watching == $this-> znode ){      printf( &quot;Nobodyhere, I'm the leader\n&quot; );      $this->setLeader( true );    }    else {      printf( &quot;I'm watching%s\n&quot; , $watching );    }  }   public function watchPrevious(){    $workers = $this->getChildren( self ::CONTAINER );    sort( $workers );    $size = sizeof( $workers );    for($i = 0 ; $i < $size ; $i&#43;&#43; ) {      if($this-> znode == $workers[$i ] ) {        if ($i > 0 ) {          $this->get( self ::CONTAINER . '/' .$workers[ $i - 1 ], array ($this, 'watchNode' ));          return $workers[$i - 1 ];        }         return $workers[$i ];      }    }     throw new Exception( sprintf( &quot;Something went very wrong! I can't find myself: %s/%s&quot;,                          self ::CONTAINER ,                          $this-> znode ));  }   public function watchNode($i, $type, $name ) {    $watching = $this->watchPrevious();    if($watching == $this-> znode ){      printf( &quot;I'm thenew leader!\n&quot; );      $this->setLeader( true );    }    else {      printf( &quot;Now I'mwatching %s\n&quot; , $watching );    }  }   public function isLeader(){    return $this-> isLeader ;  }   public function setLeader($flag){    $this-> isLeader =$flag;  }   public function run(){    $this->register();     while( true ){      if($this->isLeader() ) {        $this->doLeaderJob();    }    else {      $this->doWorkerJob();    }       sleep( 2 );    }  }   public function doLeaderJob(){    echo &quot;Leading\n&quot; ;  }   public function doWorkerJob(){    echo &quot;Working\n&quot; ;  }}$worker = new Worker( '127.0.0.1:2181' );$worker->run();可以启动3个php进程，查看脚本的运行。
进程1：
[iyunv@localhost zookeeper]# php -f worker.php
I'm registred as: w-0000000010
Nobody here, I'm the leader
Leading
进程2：
[daniel.luo@localhost zookeeper]$ php -f worker.php
I'm registred as: w-0000000011
I'm watching w-0000000010
Working
进程3：
[daniel.luo@localhost zookeeper]$ php -f worker.php
I'm registred as: w-0000000012
I'm watching w-0000000011
Working

ctrl &#43; c 关闭leader进程后，会发现进程2与3会选举出新的leader