• Flame graph: Linux performance analysis from a global perspective


    Background In our daily work, we will receive a lot of warning mail about high CPU utilization, and encounter some service failureThe CPU is fullAt this time, we need to see what process is taking up the CPU resources of the server. Usually we passtopperhapshtopTo quickly view the process that occupies the highest CPU, as […]

  • Source code analysis of spool — shared memory of memory module


    preface We know, becausePHPThere is no multithreading model, soswooleMore use of multi process model, so the code is relatively more concise, reducing the blocking and synchronization of various thread locks, but it also brings a new problem: data synchronization. Compared with multithreading, process memory can be shared directly, and data synchronization between processes depends on […]

  • Computer basic summary of 2021 autumn recruitment interview – operating system


    A series of articles: 2021 autumn recruitment interview computer foundation summary – algorithm, data structure, design pattern, Linux Computer foundation summary of 2021 autumn recruitment interview – Java foundation, JVM, spring framework Computer foundation summary of 2021 autumn recruitment interview database, redis Computer basic summary of 2021 autumn recruitment interview – operating system Computer foundation […]

  • How do technical people grow up?


    By Xiao Yi, senior technical expert of Ali culture and entertainment Introduction:In the twinkling of an eye, half of 2020 has passed. It’s time to make a mid year summary. In this article, Xiao Yi, senior technology expert of Ali entertainment, summarizes his growth and harvest in the past six years in Ali, and shares […]

  • The process of entering URL to display page


    The whole process includes two sub processesNavigationandRendering 1、 Navigation The user enters the URL and returns The browser process checks the URL and assembles the protocol to form a complete URL The browser process sends the URL request to the network process through IPC After receiving the URL request, the network process checks whether the […]

  • Hand to hand teaching you to write a command line terminal


    preface ElectronIt’s very famous. Many people may have known that it is used to develop desktop applications, but it has never been practiced in the project and lacks hands-on practice projects. Many open source command line terminals are usedElectronTo develop, this article will start from scratch, hand-in-hand teachingElectronWrite a command line terminal. As a complete […]

  • 02 operation and control of nginx


    1. Nginx command line parameters Unlike many other software systems, nginx has only a few command line parameters, which are completely configured through configuration filessudo nginx -t-C < / path / to / config > specifies a configuration file for nginx instead of the default. -T does not run, just tests the configuration file. Nginx […]

  • Notes on Linux performance optimization


    Share basisLinux performance optimizationNotes of course pictures. preface Experimental environment: Ubuntu 18.04, switch to the root authority operation To view the detailed usage of the command, you can:man xxxWhen it comes to paths, you can generallycat /x/xx/xxxWhen it comes to tools, if they are not installed, you can:apt-get install xxx CPU CPU performance index Find […]

  • The electron rendering process communicates with the main process


    thinking The main process listens for an event The rendering process triggers an event to send a message to the main process The main process receives the message from the rendering process and gives the rendering process a response The rendering process receives a response from the main process code implementation The main process listens […]

  • How to develop electron desktop program with Vue


    1、 Introduction to electron Electron is an open source project jointly maintained by GitHub and many contributors. It uses JavaScript, HTML and CSS to build cross platform desktop applications 1. Features Cross platform applications can be packaged into Mac, windows and Linux platforms Simplify desktop development (1) electron is based on chromium and Node.js (2) […]

  • Introduction of lua level CPU flame diagram


    It’s becoming more and more common to run Lua code in openresty or nginx servers because people want their non blocking web servers to have super high performance and great flexibility. Some people use Lua to complete some very simple tasks, such as checking and modifying some request header and response body data, while others […]

  • [1 minute tutorial] LNMP architecture application practical OpenSSL upgrade operation


    Due to the requirements of the actual production environment, it is necessary to upgrade the OpenSSL version in the LNMP environment to the latest version openssl-1.1.0c. The upgrade of this tool is really not a general trouble. Because it is related to various services of the system, such as SSH service, the upgrade is very […]