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In modern highly concurrent web development, API requests often require handling large amounts of HTTP connections. To improve efficiency and reduce the cost of establishing and destroying connections, connection reuse becomes particularly important. PHP's curl library and Swoole provide efficient solutions. The curl_upkeep() function is used in conjunction with Swoole to effectively realize connection multiplexing of HTTP requests and improve the concurrency performance of the system.
This article will introduce how to use the curl_upkeep() function to achieve efficient connection multiplexing with Swoole, reducing unnecessary connection overhead, and thereby improving application performance.
When making HTTP requests, a new TCP connection is usually required to initiate a request. Each time a connection is established, data is transmitted, and connection is closed, it consumes a certain amount of time and resources. Connection multiplexing allows multiple requests to share the same connection by maintaining long connections, reducing the overhead of frequently setting up and closing connections and improving overall performance.
curl_upkeep() is a custom function that keeps the connection to the target server active so that the same connection can be reused in subsequent requests. By using curl_upkeep() we can avoid re-establishing the connection every time we request, which greatly reduces latency and resource waste.
function curl_upkeep($url, $timeout = 30) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
'Connection: keep-alive', // use keep-alive head
]);
curl_exec($ch);
curl_close($ch);
}
The above code shows how to use the curl_upkeep() function to maintain a long connection to the server. By setting the Connection: keep-alive header, tell the server to maintain the connection, rather than re-establishing the connection every time you request.
Swoole is a high-performance PHP extension that provides coroutine, asynchronous IO, multi-threading and other functions, greatly improving the concurrent processing capabilities of PHP. When Swoole is used in conjunction with the curl_upkeep() function, a large number of concurrent HTTP requests can be implemented in a single process, thereby further improving the performance of the system.
In the Swoole environment, we can implement concurrent requests through coroutines and use curl_upkeep() for connection multiplexing. Swoole provides a coroutine HTTP client that simplifies code and improves efficiency.
Through the Swoole coroutine, we can make HTTP requests in multiple coroutines at the same time and share a persistent connection. Here is an example of how to use the Swoole coroutine with curl_upkeep() :
use Swoole\Coroutine\Http\Client;
Swoole\Coroutine::create(function () {
// initialization Swoole HTTP Client
$client = new Client('m66.net', 80);
$client->set([
'timeout' => 3,
'keepalive' => true, // Enable long connection
]);
// send GET ask
$client->get('/path/to/resource');
// Stay connected
curl_upkeep('http://m66.net/path/to/resource');
// Processing response
echo $client->body;
$client->close();
});
In this example, we use Swoole's coroutine HTTP client to send requests and use curl_upkeep() to keep the connection active. By enabling keepalive , the client maintains a connection to the server, sharing the same connection between multiple requests.
To fully utilize the advantages of connection multiplexing, we can also share a curl handle between multiple concurrent requests. Specifically, a shared curl resource pool can be used to manage connections, reusing the same connection between different coroutines or requests.
use Swoole\Coroutine\Pool;
$pool = new Pool(10); // Create a connection pool，Maximum support 10 Each coroutine is executed simultaneously
Swoole\Coroutine::create(function () use ($pool) {
$client = $pool->get(); // Get an idle connection from the connection pool
$client->get('http://m66.net/path/to/resource');
$pool->put($client); // Put the connection back to the connection pool
});
By using the curl_upkeep() function and the Swoole coroutine, we can efficiently implement connection multiplexing, greatly improving the system's throughput and response speed. Combined with the asynchronous IO feature of Swoole, PHP's HTTP requests can handle higher concurrent requests without adding additional resource consumption.
Using these technologies, developers can easily deal with highly concurrent web services and improve the overall performance of the system. Connection multiplexing is a very practical optimization strategy when dealing with large numbers of external API calls.
