Recommendation systems are information filtering systems designed to suggest potentially interesting content to users based on their preferences and behavioral data. From product recommendations on e-commerce websites to personalized playlists on streaming platforms, recommendation systems have perm ... More >>

Introduction Flutter is an open source user interface (UI) toolkit developed by Google for building high-performance, beautiful, and smooth mobile applications on multiple platforms. It uses the Dart programming language and provides a wealth of UI components and tools to quickly build modern applic ... More >>

promise Key pointsThe ‘Promise’ object represents an asynchronous operation with three states: ‘pending’ (in progress), ‘fulfilled’ (successful), and ‘rejected’ (failed) A Promise must be in one of the following states: pending: An initial state that is neither cashed nor rejected. fulfilled: The o ... More >>

The so-called high concurrency refers to: at the same time or within a very short period of time, there are a large number of requests to reach the server, each request requires the server to spend resources to process, and make the corresponding feedback. Commonly used ideas and tools for high conc ... More >>

IntroductionNginx (pronounced “engine-x”) is an open-source web server that also functions as a reverse proxy, load balancer, mail proxy, and HTTP cache. Created by Igor Sysoev and publicly released in 2004, Nginx has grown in popularity due to its high performance, stability, rich feature set, simp ... More >>

In the past, iOS page layout was relatively traditional, and most people used Frame or AutoLayout for layout. After iOS9, UIStackView was introduced. UIStackView is a control for linear layout that can automatically manage subview layout and automatic filling. It draws on the front-end layout algori ... More >>

Component Communication SecurityWhat is local denial of service?Before understanding local denial of service, let’s briefly understand denial of service attacks (dos attacks) and distributed denial of service attacks (ddos). The so-called denial of service attack is to occupy all the service threads ... More >>

1.conceptThe Timing Wheel is the result of George Varghese and Tony Lauck’s 1996 paper [Hashed and Hierarchical Timing Wheels: data structures to efficiently implement a timer facility], which is widely used in the Linux kernel and is one of the implementations and foundations of Linux kernel timers ... More >>

Let’s rewind a bit and have a close look at this TIME-WAIT state. What is it? See the TCP state diagram below: TCP state diagram Only the end closing the connection first will reach the TIME-WAIT state. The other end will follow a path which usually permits it to quickly get rid of the connection. ... More >>

backgroundWith the popularity of microservices, many companies have split the system into many microservices according to business boundaries, when troubleshooting and checking logs. Because business links run through many microservice nodes, it becomes very difficult to locate the logs of a certain ... More >>