Zookeeper
简单介绍
Apache Zookeeper是开发和维护开源服务器的服务，它能够实现高度可靠的分布式协调。
安装Zookeeper(无需安装)
wget http://mirror.bit.edu.cn/apache/zookeeper/zookeeper-3.4.10/zookeeper-3.4.10.tar.gztar zxvf zookeeper-3.4.10.tar.gz安装Zookeeper C扩展支持
cd zookeeper-3.4.8/src/c./configure --prefix=/usr/makemake install安装php的zookeeper扩展
wget https://pecl.php.net/get/zookeeper-0.6.2.tgztar zxvf zookeeper-0.6.2.tgzcd zookeeper-0.6.2phpize./configure --with-libzookeeper-dir=/usr/$ make$ make install启动zookeeper server
# {zookeeperserver}代表你zookeeper解压的目录mkdir -p /project/zookeeper/demo/data#zoo.conf 是默认启动所加载的配置文件cp /{zookeeperserver}/conf/zoo_sample.cfg /{zookeeperserver}/conf/zoo.cfg/{zookeeperserver}/bin/zkServer startzookeeper client 测试
/{zookeeperserver}/bin/zkCli.sh -server 127.0.0.1:2181# [zk: 127.0.0.1:2181(CONNECTED) x] 客户端连接信息shell[zk: 127.0.0.1:2181(CONNECTED) 3] ls /[zookeeper][zk: 127.0.0.1:2181(CONNECTED) 4] create /test qkl001Created /test[zk: 127.0.0.1:2181(CONNECTED) 5] create /zgq zgq002Created /zgq[zk: 127.0.0.1:2181(CONNECTED) 6] ls / [zookeeper, test, zgq][zk: 127.0.0.1:2181(CONNECTED) 5] delete /zgqCreated /zgq[zk: 127.0.0.1:2181(CONNECTED) 7] quitPHP下实践
zookeeper类信息
Zookeeper — Zookeeper类 ?-- Zookeeper::addAuth — 指定应用程序凭据 ?-- Zookeeper::connect — 创建与Zookeeper沟通的句柄 ?-- Zookeeper::__construct — 创建与Zookeeper沟通的句柄 ?-- Zookeeper::create — 同步创建节点 ?-- Zookeeper::delete — 同步删除Zookeeper中的一个节点 ?-- Zookeeper::exists — 同步检查Zookeeper节点的存在性 ?-- Zookeeper::get — 同步获取与节点关联的数据。 ?-- Zookeeper::getAcl — 同步地获取与节点关联的ACL。 ?-- Zookeeper::getChildren — 同步列出节点的子节点 ?-- Zookeeper::getClientId — 返回客户端会话ID，仅在连接当前连接时才有效（即最后观察者状态为ZooOnCeleDelphi状态） ?-- Zookeeper::getRecvTimeout — 返回此会话的超时，如果连接当前连接（只有上次观察者状态为ZooOnCeleTytStand状态）才有效。此值可能在服务器重新连接后发生更改。 ?-- Zookeeper::getState — 获取Zookeeper连接的状态 ?-- Zookeeper::isRecoverable — 检查当前的Zookeeper连接状态是否可以恢复 ?-- Zookeeper::set — 设置与节点关联的数据 ?-- Zookeeper::setAcl — 同步设置与节点关联的ACL ?-- Zookeeper::setDebugLevel — 设置库的调试级别 ?-- Zookeeper::setDeterministicConnOrder — 启用/禁用仲裁端点顺序随机化 ?-- Zookeeper::setLogStream — 设置库用于日志记录的流 ?-- Zookeeper::setWatcher — 设置观察函数客户端操作
zkCli.cmd# output 表示连接成功WatchedEvent state:SyncConnected type:None path:null[zk: localhost:2181(CONNECTED) 0]# 以下是操作命令ls /create /ztest 1获取节点信息(Zookeeper::get)
# get.php$zoo = new Zookeeper('192.168.1.45:2181');$r = $zoo->get( '/ztest');var_dump($r);获取节点信息(Zookeeper::get)并设置watcher
# get.phpclass ZookeeperDemo extends Zookeeper{ ???public function watcher($type, $state, $key) ???{ ???????var_dump($type); ???????var_dump($state); ???????var_dump($key); ???????if ($type == 3) { ???????????var_dump($this->get('/zgetw')); ???????????// Watcher gets consumed so we need to set a new one ???????????$this->get('/zgetw', array($this, 'watcher')); ???????} ???}}$zoo = new ZookeeperDemo('192.168.1.45:2181');$zoo->get('/zgetw', [$zoo, 'watcher']);while (true) { ???echo '.'; ???sleep(1);}客户端操作
set /ztest 2set /ztest 3set /ztest 5获取节点信息(Zookeeper::get) 结果
php get.php#output ......int(3)int(3)string(6) "/ztest"string(1) "2"..int(3)int(3)string(6) "/ztest"string(1) "3"..int(3)int(3)string(6) "/ztest"string(1) "4".int(3)int(3)string(6) "/ztest"string(1) "5"创建子节点
create /ztest/child1 c1# output: Created /ztest/child1create /ztest/child2 c2# output: Created /ztest/child2ls /ztest# output: [child2, child1]php下获取子节点
# getChild.php$zookeeper = new Zookeeper('192.168.1.45:2181');$path = '/ztest';$r = $zookeeper->getchildren($path);if (!empty($r)) { ???foreach ($r as $c) ???{ ???????var_dump($c); ???}}# php getChild.phpstring(6) "child2"string(6) "child1"创建顺序节点
[zk: localhost:2181(CONNECTED) 22] create /stest 1Created /stest[zk: localhost:2181(CONNECTED) 23] create -s /stest/seq 1Created /stest/seq0000000000[zk: localhost:2181(CONNECTED) 24] create -s /stest/seq 1Created /stest/seq0000000001[zk: localhost:2181(CONNECTED) 25] create -s /stest/seq 1Created /stest/seq0000000002[zk: localhost:2181(CONNECTED) 26] create -s /stest/seq 1Created /stest/seq0000000003[zk: localhost:2181(CONNECTED) 27] create -s /stest/seq 1Created /stest/seq0000000004[zk: localhost:2181(CONNECTED) 28] create -s /stest/seq 1Created /stest/seq0000000005[zk: localhost:2181(CONNECTED) 29] create -s /stest/seq 1Created /stest/seq0000000006[zk: localhost:2181(CONNECTED) 30] create -s /stest/seq 1Created /stest/seq0000000007[zk: localhost:2181(CONNECTED) 31] create -s /stest/seq 2Created /stest/seq0000000008[zk: localhost:2181(CONNECTED) 32] create -s /stest/seq 2Created /stest/seq0000000009[zk: localhost:2181(CONNECTED) 33] create -s /stest/seq 2Created /stest/seq0000000010[zk: localhost:2181(CONNECTED) 34] create -s /stest/seq 2Created /stest/seq0000000011[zk: localhost:2181(CONNECTED) 35] create -s /stest/seq 2Created /stest/seq0000000012[zk: localhost:2181(CONNECTED) 36] create -s /stest/seq 2Created /stest/seq0000000013[zk: localhost:2181(CONNECTED) 37] create -s /stest/seq 2Created /stest/seq0000000014代码
$zookeeper = new Zookeeper('192.168.1.45:2181');$aclArray = array( ???array( ???????'perms' ?=> Zookeeper::PERM_ALL, ???????'scheme' => 'world', ???????'id' ????=> 'anyone', ???));$path = '/t3';//ZOO_EPHEMERAL = 1//ZOO_SEQUENCE ?= 2//这里这里的flag=NULL,flag=0 表示创建永久节点，=1创建临时节点，=2创建seq 顺序节点$realPath = $zookeeper->create($path, null, $aclArray, 1);var_dump($realPath);worker
一个利用顺序临时节点的leader迁移实现
# worker.php<?php/** * Created by PhpStorm. * User: qkl * Date: 2018/8/27 * Time: 14:25 */class Worker{ ???const CONTAINER = '/worker_test'; ???protected $acl = [ ???????[ ???????????'perms' => Zookeeper::PERM_ALL, ???????????'scheme' => 'world', ???????????'id' => 'anyone' ???????] ???]; ???private $isLeader = false; ???private $znode = ''; ???private $prevNode = ''; ???public function __construct($host = '', $watcher_cb = null, $recv_timeout = 10000) ???{ ???????$this->zk = new Zookeeper($host, $watcher_cb, $recv_timeout); ???} ???public function register() ???{ ???????if (!$this->zk->exists(self::CONTAINER)) { ???????????$this->zk->create(self::CONTAINER, null, $this->acl); ???????} ???????# 创建一个临时的顺序节点 ???????$this->znode = $this->zk->create(self::CONTAINER . '/w-', ???????????????????????????????????????null, ???????????????????????????????????????$this->acl, ???????????????????????????????????????Zookeeper::EPHEMERAL | Zookeeper::SEQUENCE); ???????//获取顺序节点名，去除父路径 ???????$this->znode = str_replace(self::CONTAINER . '/', '', $this->znode); ???????printf("我创建了节点: %s\n", self::CONTAINER . '/' . $this->znode); ???????$this->prevNode = $this->getPrev(); ???????if (is_null($this->prevNode)) { ???????????$this->setLeader(true); ???????} else { ???????????$this->zk->get(self::CONTAINER . "/" . $this->prevNode, [$this, 'watcher']); ???????} ???} ???public function getPrev() ???{ ???????$workers = $this->zk->getChildren(self::CONTAINER); ???????sort($workers); ???????$size = count($workers); ???????for ($i = 0; $i < $size; $i++) { ???????????if ($this->znode == $workers[$i] && $i > 0) { ???????????????return $workers[$i - 1]; ???????????} ???????} ???????return null; ???} ???public function watcher($type, $state, $key) ???{ ???????$prevNode = $this->prevNode; ???????printf("watchNode-getPrevious：%s\n", self::CONTAINER . "/" . $prevNode); ???????if (!is_null($prevNode)) { ???????????if ($type == 2) { ???????????????printf($prevNode . " had deleted\n"); ???????????} ???????????if ($type == 3) { ???????????????printf("我重新监控节点：%s\n", self::CONTAINER . "/" . $prevNode); ???????????????$this->zk->get(self::CONTAINER . "/" . $prevNode, [$this, 'watcher']); ???????????} ???????} ???} ???public function isLeader() ???{ ???????return $this->isLeader; ???} ???public function setLeader($flag) ???{ ???????$this->isLeader = $flag; ???} ???public function run() ???{ ???????$this->register(); ???????while (true) { ???????????if ($this->isLeader()) { ???????????????$this->leaderJob(); ???????????} else { ???????????????$this->watcherJob(); ???????????} ???????????sleep(2); ???????} ???} ???public function leaderJob() ???{ ???????echo "现在我是Leader\n"; ???} ???public function watcherJob() ???{ ???????echo "我在监控：".(self::CONTAINER . "/" . $this->prevNode)."\n"; ???}}$worker = new Worker('192.168.1.45:2181');$worker->run();尝试
# 终端1php worker.php# 终端2php worker.php# 终端3php worker.php# 此处运行不会被节点变化不会被监控到再次尝试
# zkClicreate /worker_test/w-/worker_test/0000000020php worker.php# output我创建了节点: /worker_test/w-0000000022我在监控：/worker_test/w-0000000020我在监控：/worker_test/w-0000000020watchNode-getPrevious：/worker_test/w-0000000020我重新监控节点：/worker_test/w-0000000020我在监控：/worker_test/w-0000000020我在监控：/worker_test/w-0000000020我在监控：/worker_test/w-0000000020我在监控：/worker_test/w-0000000020我在监控：/worker_test/w-0000000020watchNode-getPrevious：/worker_test/w-0000000020我重新监控节点：/worker_test/w-00000000202018-08-28 02:11:46,684:2486(0x7f28ed0a1700):ZOO_WARN@zookeeper_interest@1570: Exceeded deadline by 15ms我在监控：/worker_test/w-0000000020我在监控：/worker_test/w-0000000020watchNode-getPrevious：/worker_test/w-0000000020w-0000000020 had deleted我在监控：/worker_test/w-0000000020这边发现一个类似bug问题
如果我们直接运行worker.php在worker.php运行创建的临时顺序节点是不会被watcher到的我们必须先首先创建好相关的节点再启动监控，不知道这里是不是php版本的zookeeper的bug有了解的小伙伴可以告之下Watcher通知状态与事件类型一览
ZOO_CREATED_EVENT(value=1)：节点创建事件，需要watch一个不存在的节点，当节点被创建时触发，此watch通过zoo_exists()设置
ZOO_DELETED_EVENT(value=2)：节点删除事件，此watch通过zoo_exists()或zoo_get()设置
ZOO_CHANGED_EVENT(value=3)：节点数据改变事件，此watch通过zoo_exists()或zoo_get()设置
ZOO_CHILD_EVENT(value=4)：子节点列表改变事件，此watch通过zoo_get_children()或zoo_get_children2()设置
ZOO_SESSION_EVENT(value=-1)：会话事件，客户端与服务端断开或重连时触发
ZOO_NOTWATCHING_EVENT(value=-2)：watch移除事件，服务端出于某些原因不再为客户端watch节点时触发
原文地址：https://segmentfault.com/a/1190000016173878
PHP和zookeeper结合实践
原文地址：https://www.cnblogs.com/lalalagq/p/9973679.html