• MySQL indexing and SQL tuning summary


    MySQL index MySQL supports many storage engines, and various storage engines support indexes differently. Therefore, MySQL database supports a variety of index types, such as BTREE index, hash index, full-text index and so on. In order to avoid confusion, this article will only focus on the BTREE index, which is the index we mainly deal […]

  • Learn a Linux command every day (112): vmstat


    Command introduction The vmstat command is used for virtual memory statistics. Vmstat reports information about processes, memory, paging, block IO, traps, disks, and CPU activity. Syntax format vmstat [options] [delay [count]] Option description -A # show active inner page -F # displays the total number of processes created since startup -M # display slab information […]

  • Operation and maintenance practice: Linux system expands the partition where Oracle database is located


    The production environment often encounters insufficient disk space. Next, let’s introduce the solution of LVM volume expansion.Operation and maintenance practice: the Linux system extends the partition where the Oracle database is located. Operation and maintenance practice: the Linux system extends the partition where the Oracle database is locatedExperimental environment:System: centos7The installation adopts LVM volume partition, […]

  • Talk about Kafka: why is Kafka so fast?


    Welcome to my official account, old Chou chat architecture, the principle of Java’s back-end technology stack, source analysis, architecture and various Internet high concurrency, high-performance and high availability solutions. 1、 Foreword We all know that Kafka is based on disk storage, but Kafka officials also say that it has the characteristics of high performance, high […]

  • For win10 and Ubuntu dual systems, the startup item is damaged after Aomei partition, and only grub > is displayed


    Pre observation tips Read this tip first. The method is not appropriate. Turn left in advance to avoid wasting your valuable time [this tutorial directly and safely deletes the Ubuntu system. If there are important files in Ubuntu, it is recommended to repair the Ubuntu startup item.] [this article is attached with some common software […]

  • Webpack Basics


    brief introduction In essence,webpackIs an example of a modern JavaScript applicationStatic module packaging tool。 When a webpack processes an application, it builds one internallyDependency graph, this dependency graph maps each module required by the project and generates one or morebundle。 webpackIt is a tool for packaging modular JavaScript. It will start from the entry module, […]

  • How to resolve abnormal data?


    When a customer database (Oracle did not make any changes, the business was frequently stuck every weekend morning. After careful diagnosis, it was preliminarily determined that tuxedo parameters reached the threshold due to the surge of business volume. After optimizing tuxedo parameters on May 10, the business interruption did not occur. A week later, […]

  • Raid concept – how raid-0-1-5-10 works


    Raid concept – how enterprise raid-0-1-5-10 works Redundant arrays of independent disks (RAID) are composed of “Independent Disks” with redundancyThe meaning of “array of capabilities” (one disk is broken and data is not lost). Disk array consists of many cheaper disks to hardware (RAID)Card) or software (mdadm) forms are combined into a disk group with […]

  • Write OS kernel from scratch – simple file system


    Series catalog Preface preparation BIOS boot to real mode GDT and protection mode On virtual memory Load and enter the kernel Display and print Global descriptor table GDT Interrupt processing Virtual memory perfection Implement heap and malloc First kernel thread Multithreading operation and switching Lock and multithreading synchronization Enter user status Process implementation system call […]

  • Learn a Linux command every day (117): atop


    Command introduction Atop command is a tool for monitoring Linux system resources and processes. It is not an internal command and needs to be installed. [[email protected] ~]# atop -bash: atop: command not found [[email protected] ~]# yum install atop -y #Debian && Ubuntu apt-get install atop #Fedora dnf install atop Atop records the operation status of […]

  • Learn a Linux command every day (116): cfdisk


    Command introduction The cfdisk command can be used to display information about the disk partition table. Its function andfdiskThe same, but it has a text-based “graphical” interface, which is more intuitive, easy to use and convenient in operation and visualization. The above is the graphical interface of cfdisk Syntax format cfdisk [-agvz] [-c cylinders] [-h heads] [-s sectors-per-track]  [-P opt] [device] Option description -a  # […]

  • How to perform Linux performance analysis in 60 seconds


    When you log in to a Linux server and need to do performance analysis because of a problem: what tests will you do in the first minute? In Netflix, we have many EC2 Linux machines, and we also need many performance analysis tools to monitor and check their performance. It includes atlas, a monitoring tool […]