在此链接https://www.oreilly.com/library/view/kafka-the-definitive/9781491936153/ch04.html中，标题为“使用具有特定偏移量的记录的消费”部分引用了一种策略，该策略有效地“按需更新”外部存储中的主题分区偏移量，然后撤销分区（例如重新平衡）只需将任何中断的事务提交到外部存储。
现在，我假设此策略意味着在分区撤销回调中，我不需要处理传入的TopicPartition集合的偏移量，因为任何被中断的“进行中”事务都将保留并将包含需要提交/保存的分区偏移量。
（如果我对此有误，请纠正我。）
那么，既然这是Spring Kafka，并且我正在使用@Transactional服务来保存必要的数据，那么上述策略是否相关/可行？换句话说，我不确定如何恢复/提交标记为@Transactional的内容，因为事务管理器，边界等都是在后台进行处理的。
这甚至是个问题吗？如果是这样，那么实现此策略的最佳方法是什么？手动跟踪交易（在方法和回调之间听起来很糟糕）？
还是我应该在分区撤销时浏览TopicPartition集合并更新分区偏移量？
希望这很有意义，因为我想确保我做对了。
谢谢。
答案 0 :(得分：0)
2017年9月发布
从卡夫卡的角度来看，那本书很老。具有现代版本；在Kafka中保留偏移量要简单得多；只需确保您的消费者可以处理<?php
namespace Sample;
require_once '/home/server/public/vendor/autoload.php';
//1. Import the PayPal SDK client that was created in `Set up Server-Side SDK`.
use Sample\PayPalClient;
use PayPalCheckoutSdk\Orders\OrdersGetRequest;
use PayPalCheckoutSdk\Core\PayPalHttpClient;
use PayPalCheckoutSdk\Core\SandboxEnvironment;
ini_set('error_reporting', E_ALL); // or error_reporting(E_ALL);
ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
class PayPalClient
{
/**
* Returns PayPal HTTP client instance with environment that has access
* credentials context. Use this instance to invoke PayPal APIs, provided the
* credentials have access.
*/
public static function client()
{
return new PayPalHttpClient(self::environment());
}
/**
* Set up and return PayPal PHP SDK environment with PayPal access credentials.
* This sample uses SandboxEnvironment. In production, use LiveEnvironment.
*/
public static function environment()
{
$clientId = getenv("CLIENT_ID") ?: "CLIENT_ID-here";
$clientSecret = getenv("CLIENT_SECRET") ?: "CLIENT_SECRET-here";
return new SandboxEnvironment($clientId, $clientSecret);
}
}
class GetOrder
{
// 2. Set up your server to receive a call from the client
/**
*You can use this function to retrieve an order by passing order ID as an argument.
*/
public static function getOrder($orderId)
{
echo "testtttt ".$orderId;
// 3. Call PayPal to get the transaction details
$client = PayPalClient::client();
$response = $client->execute(new OrdersGetRequest($orderId));
/**
*Enable the following line to print complete response as JSON.
*/
print json_encode($response->result);
print "Status Code: {$response->statusCode}\n";
print "Status: {$response->result->status}\n";
print "Order ID: {$response->result->id}\n";
print "Intent: {$response->result->intent}\n";
print "Links:\n";
foreach($response->result->links as $link)
{
print "\t{$link->rel}: {$link->href}\tCall Type: {$link->method}\n";
}
// 4. Save the transaction in your database. Implement logic to save transaction to your database for future reference.
print "Gross Amount: {$response->result->purchase_units[0]->amount->currency_code} {$response->result->purchase_units[0]->amount->value}\n";
// To print the whole response body, uncomment the following line
// echo json_encode($response->result, JSON_PRETTY_PRINT);
}
}
/**
*This driver function invokes the getOrder function to retrieve
*sample order details.
*
*To get the correct order ID, this sample uses createOrder to create a new order
*and then uses the newly-created order ID with GetOrder.
*/
$request_body = file_get_contents('php://input');
$data = json_decode($request_body);
print_r($data);
echo 'order id = '.$data->orderID;
if (!count(debug_backtrace()))
{
GetOrder::getOrder($data->orderID, true);
}
?>
中poll()返回的所有记录，以避免完全重新平衡。