Php connection to a zookeeper instance-php Tutorial

Php connects to zookeeper instance 1. after zookeeper is installed successfully, the corresponding startup script is started in the bin directory of zookeeper.

Start Server

./ZkServer. sh start

Start the client: (* Note: java must be installed for cli)

ZkCli. sh

2. PHP instance:

ClassZookeeperDemoExtendsZookeeper {

Public functionWatcher ($ I, $ type, $ key ){

Echo"Insider Watcher \ n ";

// Watcher gets consumed so we need to set a new one

$ This-> get ('/test ',Array($ This, 'Watcher '));

}

}

$ Zoo =NewZookeeperDemo ('2017. 0.0.1: 100 ');

$ Zoo-> get ('/test ',Array($ Zoo, 'Watcher '));

While(True){

Echo'.';

Sleep (2 );

}

Assignment of leader and worker tasks:

ClassWorkerExtendsZookeeper {

ConstCONTAINER = '/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 functionRegister (){

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 ("I'm registred as: % s \ n", $ this-> znode );

$ Watching = $ this-> watchPrevious ();

If($ Watching ==$ this-> znode ){

Printf ("Nobody here, I'm the leader \ n ");

$ This-> setLeader (True);

}

Else{

Printf ("I'm watching % s \ n", $ watching );

}

}

Public functionWatchPrevious (){

$ Workers = $ this-> getChildren (Self: CONTAINER );

Sort ($ workers );

$ Size = sizeof ($ workers );

For($ I = 0; $ I <$ size; $ I ++ ){

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 newException (sprintf ("Something went very wrong! I can't find myself: % s/% s ",

Self: CONTAINER,

$ This-> znode ));

}

Public functionWatchNode ($ I, $ type, $ name ){

$ Watching = $ this-> watchPrevious ();

If($ Watching ==$ this-> znode ){

Printf ("I'm the new leader! \ N ");

$ This-> setLeader (True);

}

Else{

Printf ("Now I'm watching % s \ n", $ watching );

}

}

Public functionIsLeader (){

Return$ This-> isLeader;

}

Public functionSetLeader ($ flag ){

$ This-> isLeader = $ flag;

}

Public functionRun (){

$ This-> register ();

While(True){

If($ This-> isLeader ()){

$ This-> doLeaderJob ();

}

Else{

$ This-> doWorkerJob ();

}

Sleep (2 );

}

}

Public functionDoLeaderJob (){

Echo"Leading \ n ";

}

Public functionDoWorkerJob (){

Echo"Working \ n ";

}

}

$ Worker =NewWorker ('127. 0.0.1: 100 ');

$ Worker-> run ();

You can start three php processes to view the script running.
Process 1:
[Root @ localhost zookeeper] # php-f worker. php
I'm registred as: w-0000000010
Nobody here, I'm the leader
Leading
Process 2:
[Daniel. luo @ localhost zookeeper] $ php-f worker. php
I'm registred as: w-0000000011
I'm watching w-0000000010
Working
Process 3:
[Daniel. luo @ localhost zookeeper] $ php-f worker. php
I'm registred as: w-0000000012
I'm watching w-0000000011
Working

After ctrl + c closes the leader process, it will find that process 2 and 3 will elect a new leader