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This article mainly introduces the relevant knowledge of "what is the architecture of web multithreaded programs and single-process programs". The editor shows you the operation process through actual cases, and the operation method is simple, fast and practical. I hope this article "what is the architecture of web multithreaded programs and single-process programs" can help you solve the problem.

It is used in both multithreaded programs and single-process programs, and in network services. Multithreaded programs are mainly used to process some requests synchronously in order to process more requests at the same time. The strategy of thread pool is generally adopted, and a main thread is used to allocate requests.

(1) Common process models:

(1) multithreading model

In this mode, the number of threads is fixed and the throughput is close to the number of threads per thread. It does not have the flexibility, the scalability is not strong, and the capacity is very limited under high load. It is widely used for synchronous data access when the load is not heavy.

(2) multithreading model II

In this model, a thread is responsible for scheduling tasks to different threads, usually maintaining a thread pool, and the number of threads in the thread pool can be scaled, which is determined by the scheduling thread. The reward is also handled by scheduling threads, and threads can communicate in other ways by sharing memory. But there is also a limit to the number of threads.

(1) single process model

This model uses the full asynchronous mode to process the request, the process maintains a global queue of each request, the worker process and the network process are independent, and uses the shared memory mode to communicate. In the case of full asynchronous, it can also achieve high concurrency and high throughput. This model is easy to control and needs to be protected from overload.

(2) comparison of several common models

(1) Program complexity

The most complex is to use the thread pool with scheduling function, this model requires a scheduling thread, the work of the scheduling thread includes assigning worker threads, overload protection, communicating with multiple threads and synchronizing. Shared resources between threads should be locked, so that shared resources can be eliminated and processing capacity can be improved. It can be accessed in synchronous processing mode, but it is risky.

The single-process model is relatively simple, a process will complete all functions, including packet collection, logical processing, overload protection.

(2) performance

Generally speaking, the front end that receives requests with multi-client, multi-version and multi-protocol is suitable to adopt multi-thread mode. If there is a unified protocol format, it should be completed by thread pool with scheduling threads. If the protocol is different, it needs to be solved by using different threads to listen to different ports.

Backend services are generally suitable for single process. Background threads require high concurrency and high throughput. The single-process model eliminates locks and avoids many complex problems of multithreading. Another big disadvantage of multithreading in the development process is that it is not conducive to debugging. There is a high demand for the developers' modulation skills.

Multithreading is also used in the background, and a single process is generally used in the background.

(3) Competition

Multithreading has competition problems, and multithreading will encounter many program traps. Global data, queues, map and other data structures need to be locked.

It is obvious that there is no competitive problem in a single-threaded program, and it is relatively simple to program in a single-threaded program. Many timing and competitive problems do not exist.

(4) Service robustness

In multithreading, a problem with any thread will cause the whole process to hang up, which is no different from a single process. One of the benefits of multithreading is that synchronous api can be called, while only asynchronous API is generally allowed in single-process network services.

This is the end of the introduction on "what is the architecture of web multithreaded programs and single-process programs". Thank you for reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.

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