javascript - If there are multiple ajax accesses to the background on a page, is the background single-threaded at this time? Or multi-threaded

If the backend uses the thinkphp framework and multiple ajaxes on the page access the backend server, will the backend server operate asynchronously with single threads or multi-threads at this time? I hope someone who knows me can tell me

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If the backend uses the thinkphp framework and multiple ajaxes on the page access the backend server, will the backend server operate asynchronously with single threads or multi-threads at this time? I hope someone who knows me can tell me

The default is multi-process, not multi-thread, and one process handles one request. PHP multi-threading requires the installation of extension implementations, but the same process still receives an http request. Unless you implement a web server in PHP and then distribute the request using multi-threading, you can implement one thread and one request.
Apache defaults to prefork working mode. PHP is a module module. A new process is created in response to a request. The maximum number of processes depends on the apache configuration. nginx communicates with php-fpm through fast-cgi, which is also a process per request. The maximum number of processes depends on the php-fpm configuration.
If the backend processing time of a request is too long and it is blocked, and multiple identical requests will fill up the number of processes, all subsequent requests will be waiting for available sockets

This depends on your server, whether it is single-threaded or multi-threaded, or even multi-process.

What I understand about single thread and multithread is this,

For example, if you use a formto upload a file, ​​this is just a request. You only initiated a request to upload a file. After receiving your request to upload a file, the server found that your file was really big. He wanted it to be If he had to carry it alone, he probably wouldn't be able to get off work at 10 pm. Then he automatically (fork) some helpers, which is equivalent to creating some new threads to help him complete the file upload. Multi-person collaboration must be very fast, so You can complete your large file upload in minutes, this is multi-threading,

Single threading means one person has to work hard until dawn,

So, whether the server is single-threaded or multi-threaded does not depend on how many requests your client initiates. The client initiates 10,000 requests at the same time (whether synchronously or asynchronously). This is called concurrency, and multi-threading It doesn’t matter,

A single thread cannot implement concurrent requests.

You can imagine this scenario: the user's download speed is 1k, and then requests a 1M picture. If the server is single-threaded, the next request will take 17 minutes to start responding. Obviously, it is impossible for you to play like this.

So the web server must be multi-threaded.

In terms of the number of threads, it is usually a single digit above 4. However, this is a limitation of the browser. There is a limit to the number of requests initiated by a single page. If there are too many, they will be thrown into the queue and wait. This is why sometimes a page It quoted Google's CDN file, but even the web page images were stuck and could not be loaded.

What I’m confused about is this: What I’m confused about is that apache+php is blocking and nginx+php is asynchronous. So if it is an apache server, is PHP blocked in responding to ajax requests?

php is a single-process single-thread model. The ajax request you mentioned is also equivalent to an http request, so there is no multi-threading. The ajax of js is implemented by asynchronous request! ! !

The client-side concurrency and server-side request processing methods (single-threaded, multi-threaded) depend on the application scenario. In most scenarios, the server-side is parallel and non-blocking