PHP中Zookeeper连接池的实现方式

在 PHP 中实现 Zookeeper 连接池，你可以使用开源库 php-zookeeper。以下是一个简单的实现方式：

1. 首先，确保已经安装了 php-zookeeper 库。你可以使用 Composer 安装：

composer require zookeeper/zookeeper

2. 创建一个 Zookeeper 连接池类，例如 ZookeeperPool.php：

<?php

use Zookeeper;

class ZookeeperPool
{
    private $zk;
    private $hosts;
    private $pool;
    private $maxConnections;

    public function __construct($hosts, $maxConnections = 5)
    {
        $this->hosts = $hosts;
        $this->maxConnections = $maxConnections;
        $this->pool = [];
    }

    public function connect()
    {
        if (empty($this->pool)) {
            for ($i = 0; $i < $this->maxConnections; $i++) {
                $this->pool[] = $this->createConnection();
            }
        }

        $key = array_rand($this->pool);
        return $this->pool[$key];
    }

    private function createConnection()
    {
        $zk = new Zookeeper();
        $connection = $zk->connect($this->hosts, 3000); // 设置连接超时时间（毫秒）

        if (!$connection) {
            throw new Exception("Failed to connect to Zookeeper");
        }

        return $connection;
    }

    public function releaseConnection($connection)
    {
        if (is_resource($connection)) {
            $key = array_search($connection, $this->pool);
            if ($key !== false) {
                unset($this->pool[$key]);
            }
        }
    }

    public function __destruct()
    {
        foreach ($this->pool as $connection) {
            if (is_resource($connection)) {
                $this->releaseConnection($connection);
            }
        }
    }
}

3. 使用 ZookeeperPool 类创建一个连接池实例：

<?php

require_once 'ZookeeperPool.php';

$hosts = '127.0.0.1:2181'; // Zookeeper 服务器地址和端口
$maxConnections = 10; // 最大连接数

$zkPool = new ZookeeperPool($hosts, $maxConnections);

4. 从连接池中获取和释放连接：

<?php

// 获取连接
$zk = $zkPool->connect();

// 使用连接操作 Zookeeper
// ...

// 释放连接
$zkPool->releaseConnection($zk);

这样，你就实现了一个简单的 Zookeeper 连接池。你可以根据需要调整连接池的大小和连接超时时间。