The Zookeeper class

(PECL zookeeper >= 0.1.0)

Introduction

Represents ZooKeeper session.

Class synopsis

Zookeeper {

/* Methods */

public __construct ([ string $host = '' [, callable $watcher_cb = NULL [, int $recv_timeout = 10000 ]]] )

public bool addAuth ( string $scheme , string $cert [, callable $completion_cb = NULL ] )

public void close ( void )

public void connect ( string $host [, callable $watcher_cb = NULL [, int $recv_timeout = 10000 ]] )

public string create ( string $path , string $value , array $acls [, int $flags = NULL ] )

public bool delete ( string $path [, int $version = -1 ] )

public bool exists ( string $path [, callable $watcher_cb = NULL ] )

public string get ( string $path [, callable $watcher_cb = NULL [, array &$stat = NULL [, int $max_size = 0 ]]] )

public array getAcl ( string $path )

public array getChildren ( string $path [, callable $watcher_cb = NULL ] )

public int getClientId ( void )

public ZookeeperConfig getConfig ( void )

public int getRecvTimeout ( void )

public int getState ( void )

public bool isRecoverable ( void )

public bool set ( string $path , string $value [, int $version = -1 [, array &$stat = NULL ]] )

public bool setAcl ( string $path , int $version , array $acl )

public static bool setDebugLevel ( int $logLevel )

public static bool setDeterministicConnOrder ( bool $yesOrNo )

public bool setLogStream ( resource $stream )

public bool setWatcher ( callable $watcher_cb )

/* Constants */

const integer PERM_READ = 1 ;

const integer PERM_WRITE = 2 ;

const integer PERM_CREATE = 4 ;

const integer PERM_DELETE = 8 ;

const integer PERM_ADMIN = 16 ;

const integer PERM_ALL = 31 ;

const integer EPHEMERAL = 1 ;

const integer SEQUENCE = 2 ;

const integer LOG_LEVEL_ERROR = 1 ;

const integer LOG_LEVEL_WARN = 2 ;

const integer LOG_LEVEL_INFO = 3 ;

const integer LOG_LEVEL_DEBUG = 4 ;

const integer EXPIRED_SESSION_STATE = -112 ;

const integer AUTH_FAILED_STATE = -113 ;

const integer CONNECTING_STATE = 1 ;

const integer ASSOCIATING_STATE = 2 ;

const integer CONNECTED_STATE = 3 ;

const integer READONLY_STATE = 5 ;

const integer NOTCONNECTED_STATE = 999 ;

const integer CREATED_EVENT = 1 ;

const integer DELETED_EVENT = 2 ;

const integer CHANGED_EVENT = 3 ;

const integer CHILD_EVENT = 4 ;

const integer SESSION_EVENT = -1 ;

const integer NOTWATCHING_EVENT = -2 ;

const integer SYSTEMERROR = -1 ;

const integer RUNTIMEINCONSISTENCY = -2 ;

const integer DATAINCONSISTENCY = -3 ;

const integer CONNECTIONLOSS = -4 ;

const integer MARSHALLINGERROR = -5 ;

const integer UNIMPLEMENTED = -6 ;

const integer OPERATIONTIMEOUT = -7 ;

const integer BADARGUMENTS = -8 ;

const integer INVALIDSTATE = -9 ;

const integer NEWCONFIGNOQUORUM = -13 ;

const integer RECONFIGINPROGRESS = -14 ;

const integer OK = 0 ;

const integer APIERROR = -100 ;

const integer NONODE = -101 ;

const integer NOAUTH = -102 ;

const integer BADVERSION = -103 ;

const integer NOCHILDRENFOREPHEMERALS = -108 ;

const integer NODEEXISTS = -110 ;

const integer NOTEMPTY = -111 ;

const integer SESSIONEXPIRED = -112 ;

const integer INVALIDCALLBACK = -113 ;

const integer INVALIDACL = -114 ;

const integer AUTHFAILED = -115 ;

const integer CLOSING = -116 ;

const integer NOTHING = -117 ;

const integer SESSIONMOVED = -118 ;

const integer NOTREADONLY = -119 ;

const integer EPHEMERALONLOCALSESSION = -120 ;

const integer NOWATCHER = -121 ;

const integer RECONFIGDISABLED = -122 ;

}

Predefined Constants

ZooKeeper Permissions

Zookeeper::PERM_READ: Can read nodes value and list its children
Zookeeper::PERM_WRITE: Can set the nodes value
Zookeeper::PERM_CREATE: Can create children
Zookeeper::PERM_DELETE: Can delete children
Zookeeper::PERM_ADMIN: Can execute set_acl()
Zookeeper::PERM_ALL: All of the above flags ORd together

ZooKeeper Create Flags

Zookeeper::EPHEMERAL: If Zookeeper::EPHEMERAL flag is set, the node will automatically get removed if the client session goes away.
Zookeeper::SEQUENCE: If the Zookeeper::SEQUENCE flag is set, a unique monotonically increasing sequence number is appended to the path name. The sequence number is always fixed length of 10 digits, 0 padded.

ZooKeeper Log Levels

Zookeeper::LOG_LEVEL_ERROR: Outputs only error mesages
Zookeeper::LOG_LEVEL_WARN: Outputs errors/warnings
Zookeeper::LOG_LEVEL_INFO: Outputs big action messages besides errors/warnings
Zookeeper::LOG_LEVEL_DEBUG: Outputs all

ZooKeeper States

Zookeeper::EXPIRED_SESSION_STATE: Connected but session expired
Zookeeper::AUTH_FAILED_STATE: Connected but auth failed
Zookeeper::CONNECTING_STATE: Connecting
Zookeeper::ASSOCIATING_STATE: Associating
Zookeeper::CONNECTED_STATE: Connected
Zookeeper::READONLY_STATE: TODO: help us improve this extension.
Zookeeper::NOTCONNECTED_STATE: Connection failed

ZooKeeper Watch Types

Zookeeper::CREATED_EVENT

A node has been created

This is only generated by watches on non-existent nodes. These watches are set using Zookeeper::exists.

Zookeeper::DELETED_EVENT

A node has been deleted

This is only generated by watches on nodes. These watches are set using Zookeeper::exists and Zookeeper::get.

Zookeeper::CHANGED_EVENT

A node has changed

This is only generated by watches on nodes. These watches are set using Zookeeper::exists and Zookeeper::get.

Zookeeper::CHILD_EVENT

A change as occurred in the list of children

This is only generated by watches on the child list of a node. These watches are set using Zookeeper::getChildren.

Zookeeper::SESSION_EVENT

A session has been lost

This is generated when a client loses contact or reconnects with a server.

Zookeeper::NOTWATCHING_EVENT

A watch has been removed

This is generated when the server for some reason, probably a resource constraint, will no longer watch a node for a client.

ZooKeeper System and Server-side Errors

Zookeeper::SYSTEMERROR

This is never thrown by the server, it shouldn't be used other than to indicate a range. Specifically error codes greater than this value, but lesser than Zookeeper::APIERROR, are system errors.

Zookeeper::RUNTIMEINCONSISTENCY

A runtime inconsistency was found.

Zookeeper::DATAINCONSISTENCY

A data inconsistency was found.

Zookeeper::CONNECTIONLOSS

Connection to the server has been lost.

Zookeeper::MARSHALLINGERROR

Error while marshalling or unmarshalling data.

Zookeeper::UNIMPLEMENTED

Operation is unimplemented.

Zookeeper::OPERATIONTIMEOUT

Operation timeout.

Zookeeper::BADARGUMENTS

Invalid arguments.

Zookeeper::INVALIDSTATE

Invliad zhandle state.

Zookeeper::NEWCONFIGNOQUORUM

No quorum of new config is connected and up-to-date with the leader of last commmitted config - try invoking reconfiguration after new servers are connected and synced.

Available as of ZooKeeper 3.5.0

Zookeeper::RECONFIGINPROGRESS

Reconfiguration requested while another reconfiguration is currently in progress. This is currently not supported. Please retry.