PHP中Zookeeper連接池的實現方式

在 PHP 中實現 Zookeeper 連接池，你可以使用開源庫 php-zookeeper。以下是一個簡單的實現方式：

1. 首先，確保已經安裝了 php-zookeeper 庫。你可以使用 Composer 安裝：

composer require zookeeper/zookeeper

2. 創建一個 Zookeeper 連接池類，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); // 設置連接超時時間（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 類創建一個連接池實例：

<?php

require_once 'ZookeeperPool.php';

$hosts = '127.0.0.1:2181'; // Zookeeper 服務器地址和端口
$maxConnections = 10; // 最大連接數

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

4. 從連接池中獲取和釋放連接：

<?php

// 獲取連接
$zk = $zkPool->connect();

// 使用連接操作 Zookeeper
// ...

// 釋放連接
$zkPool->releaseConnection($zk);

這樣，你就實現了一個簡單的 Zookeeper 連接池。你可以根據需要調整連接池的大小和連接超時時間。