PHP rdkafka如何实现消息重放

在PHP中使用rdkafka实现消息重放，可以通过以下步骤进行操作：

1. 创建一个消费者实例，并订阅相应的主题。

$conf = new \RdKafka\Conf();
$conf->set('group.id', 'myGroup');
$conf->set('bootstrap.servers', 'localhost:9092');
$consumer = new \RdKafka\KafkaConsumer($conf);
$consumer->subscribe(['myTopic']);

2. 持续轮询并处理消息。

while (true) {
    $message = $consumer->consume(120*1000);

    switch ($message->err) {
        case RD_KAFKA_RESP_ERR__PARTITION_EOF:
            // End of partition reached, but more messages are available
            echo "Reached end of partition event\n";
            break;
        case RD_KAFKA_RESP_ERR__TIMED_OUT:
            // Timeout occurred
            echo "Timed out\n";
            break;
        case RD_KAFKA_RESP_ERR__PARTITION_NOT_FOUND:
            // Partition does not exist
            echo "Partition does not exist\n";
            break;
        case RD_KAFKA_RESP_ERR__UNKNOWN:
            // Unknown error
            echo "Unknown error\n";
            break;
        default:
            // Handle other errors
            echo "Error: " . $message->errstr() . "\n";
            break;
    }

    if ($message->err == RD_KAFKA_RESP_ERR__PARTITION_EOF) {
        // Continue consuming from this partition
        $consumer->seek($message->partition, 0);
    } elseif ($message->err != RD_KAFKA_RESP_ERR__NO_ERROR) {
        // Handle the error appropriately
        break;
    }

    // Process the message
    $payload = $message->payload;
    $topic = $message->topic;
    $offset = $message->offset;
    echo "Message received: " . $payload . "\n";

    // Implement your logic to replay the message or handle it as needed
}

3. 在处理消息的逻辑中，如果需要重放消息，可以使用rdkafka的produce方法将消息发送回同一个主题。

// Assuming you want to replay the message on the same topic
$producer = new \RdKafka\Producer();
$producer->addBrokers('localhost:9092');
$producer->setMetadataRefreshIntervalMs(10000);
$producer->setMetadataRefreshIntervalCallback(function () use ($producer) {
    $producer->refreshMetadata();
});
$producer->start();

// Produce the message back to the same topic
$producer->produce([
    'topic' => $topic,
    'value' => $payload,
    'key' => '', // Optional: If you want to specify a key, pass it here
]);

// Wait for the message to be sent
$producer->flush();

通过这种方式，可以在处理消息时选择性地重放消息，确保消息被正确处理。