PHP操作Zookeeper節點監控與告警的實現

在PHP中操作Apache ZooKeeper進行節點監控和告警的實現可以分為以下幾個步驟：

1. 安裝和配置ZooKeeper 首先，確保你已經在服務器上安裝并啟動了ZooKeeper。你可以從ZooKeeper官方網站下載并安裝它：https://zookeeper.apache.org/download.html

2. 安裝PHP的ZooKeeper客戶端庫 為了在PHP中與ZooKeeper交互，你需要安裝一個客戶端庫。推薦使用php-zookeeper庫，你可以通過Composer安裝它：

composer require zookeeper/zookeeper

3. 編寫PHP代碼來監控ZooKeeper節點 創建一個PHP腳本，使用php-zookeeper庫連接到ZooKeeper并監控指定節點。例如，監控一個名為/my_node的節點：

<?php
require_once __DIR__ . '/vendor/autoload.php';

use Zookeeper;

$zk = new Zookeeper();
$connection_string = '127.0.0.1:2181';
$timeout = 3000; // 連接超時時間（毫秒）

if (!$zk->connect($connection_string, $timeout)) {
    die("Failed to connect to ZooKeeper");
}

$nodePath = "/my_node";
$watchType = Zookeeper::WATCH_EVENT_NODE_Children;

$callback = function ($data) use ($nodePath) {
    echo "Node $nodePath has been modified\n";
};

try {
    $stat = $zk->exists($nodePath, $watchType, $callback);
} catch (ZookeeperException $e) {
    echo "Error: " . $e->getMessage();
}

// Keep the script running to continuously monitor the node
while (true) {
    sleep(1);
}

$zk->close();
?>

4. 實現告警功能 為了實現告警功能，你可以將監控結果發送到告警服務，例如發送電子郵件或短信。這里以發送電子郵件為例，使用PHPMailer庫：

composer require phpmailer/phpmailer

修改監控腳本，添加電子郵件告警功能：

<?php
require_once __DIR__ . '/vendor/autoload.php';

use Zookeeper;
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

$zk = new Zookeeper();
$connection_string = '127.0.0.1:2181';
$timeout = 3000; // 連接超時時間（毫秒）

if (!$zk->connect($connection_string, $timeout)) {
    die("Failed to connect to ZooKeeper");
}

$nodePath = "/my_node";
$watchType = Zookeeper::WATCH_EVENT_NODE_CHILDREN;

$callback = function ($data) use ($nodePath) {
    echo "Node $nodePath has been modified\n";
    sendEmailAlert($nodePath);
};

try {
    $stat = $zk->exists($nodePath, $watchType, $callback);
} catch (ZookeeperException $e) {
    echo "Error: " . $e->getMessage();
}

// Keep the script running to continuously monitor the node
while (true) {
    sleep(1);
}

$zk->close();

function sendEmailAlert($nodePath)
{
    $mail = new PHPMailer(true);

    try {
        // Server settings
        $mail->isSMTP();                                            // Send using SMTP
        $mail->Host       = 'smtp.example.com';                     // Set the SMTP server to send through
        $mail->SMTPAuth   = true;                                   // Enable SMTP authentication
        $mail->Username   = 'your_email@example.com';                     // SMTP username
        $mail->Password   = 'your_email_password';                               // SMTP password
        $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;         // Enable TLS encryption; `PHPMailer::ENCRYPTION_SMTPS` encouraged
        $mail->Port       = 587;                                    // TCP port to connect to, use 465 for `PHPMailer::ENCRYPTION_SMTPS` above

        // Recipients
        $mail->setFrom('your_email@example.com', 'Your Name');
        $mail->addAddress('recipient@example.com', 'Recipient Name');     // Add a recipient

        // Content
        $mail->isHTML(true);                                  // Set email format to HTML
        $mail->Subject = 'ZooKeeper Node Alert: ' . $nodePath;
        $mail->Body    = "A node has been modified:\n$nodePath";

        $mail->send();
        echo 'Message has been sent';
    } catch (Exception $e) {
        echo "Message could not be sent. Mailer Error: {$mail->ErrorInfo}";
    }
}
?>

現在，當/my_node節點發生變化時，監控腳本將發送一封電子郵件通知。你可以根據需要修改此腳本以適應你的環境和告警服務。