Is php not suitable for long connections?

PHP is a widely used server-side programming language suitable for a variety of application scenarios. In terms of network communication, long link technologies like WebSocket require a continuous connection and are therefore very different from PHP's short link model. This has also led many people to believe that PHP is not suitable for long connections.

However, in actual application, although PHP is a short connection model, we cannot deny that PHP has some solutions suitable for long connection scenarios. Below we will discuss the feasibility and implementation of PHP long connections.

Long connection and short connection

In the field of network communication, the two commonly used connection methods are long connection and short connection.

Short connection means disconnecting the connection immediately after transmitting the data, which requires frequent three-way handshake and four-way wave. The advantage is that it is easy to maintain the connection status, but the disadvantage is that the connection needs to be established frequently, causing system overhead.

Long connections maintain the connection status after establishing a connection and can continuously transmit data. The advantage is that it saves system resources. The disadvantage is that it requires maintaining a long-term connection status, which can easily lead to resource waste and memory leaks.

The feasibility of PHP long connections

Because the PHP scripting language itself does not support long connections, many people think that PHP is not suitable for long connections. However, in actual applications, PHP can be used in combination with other applications and technologies to implement long-term connection application scenarios.

For example, you can use PHP combined with WebSocket to implement long connections. WebSocket is an application layer protocol that performs a handshake on the HTTP protocol and then upgrades the TCP connection to full-duplex communication. In this way, a persistent connection can be maintained between the client and the server, by exchanging messages in real time.

In addition, you can use PHP combined with Redis to implement long connections. Redis is a memory-based data structure storage system that provides a variety of data structures and data operation methods. It supports publish/subscribe mode and can be used to implement Message queue, task queue and other functions.

The implementation method of PHP long connection

1. WebSocket

WebSocket is a protocol based on the HTTP protocol, supports full-duplex communication, and can be used Implement long connections. PHP can implement WebSocket server through PHP WebSocket related libraries, such as Ratchet. The advantage of using WebSocket is that it supports full-duplex communication and real-time data push. The disadvantage is that the client needs to support the WebSocket protocol.

2. Redis

Redis is a memory-based data structure storage system that supports a variety of data structures and data operation methods and can be implemented through the publish/subscribe model. Message queue, task queue and other functions. PHP can use Predis or Redis extensions to interact with Redis.

3. Process Pool

Long connections need to continuously receive client requests, which will lead to frequent connections, closures, and memory allocation and release operations, making the system become Slow and inefficient. To solve this problem, you can use a process pool to improve the efficiency of your code. PHP's Swoole extension provides process pool support, which can effectively improve the performance of long-connection servers.

Conclusion

Because the PHP scripting language itself does not support long connections, PHP cannot be used directly to implement long connections. But in actual applications, PHP can be used in combination with other technologies and applications, such as WebSocket, Redis, and process pools, to implement long-connection application scenarios.

Although PHP is not the most ideal long connection tool, it can solve the problem of long connections to a certain extent. I believe that with the continuous development of technology, more long-term connection solutions suitable for PHP will appear in the future.

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