• Using stratis to manage local storage in centos8 (2)


    This article describes how to add new disks and cache disks to an existing stratis pool. Add, delete, snapshot, etc. are described below.System environmentCentos8Add additional disks to the stratis poolUnder stratis management, it is easy to add new block devices to an existing pool. In the previous article “creating stratis local storage in CentOS (I)”, […]

  • 14k Star! A fast, safe and efficient backup program!


    brief introduction Restic is a fast, efficient and secure backup program. It supports three major operating systems (Linux, MacOS, windows) and some smaller operating systems (FreeBSD, OpenBSD). Project address: https://github.com/restic/restic install Here we only introduce the installation methods of the three operating systems. For other types of operating systems, please refer to the official website. […]

  • Snapshot reading and lock reading – Notes on MySQL 8.0 official documents (III)


    Document version: 8.0Source:Consistent Nonlocking Reads 、Locking ReadsPrevious:Transaction isolation level This article mainly introduces the snapshot read and lock read of InnoDB.Strictly speaking, snapshot reading should be translated into consistent nonlocking reads, but it is generally called snapshot reading in China. It was mentioned in the previous chapterOrdinary reading、Unlocked readandConsistent readingWait, in fact, we are talking […]

  • Principle analysis of rrweb recording and playback


    Recently, when doing web recording and playback, I encountered a better library rrweb, but there are relatively few online materials. I reviewed the source code and made a small summary. After reading this article, you will probably understand the following aspects~ What is rrweb Applicable scenario Implementation principle of recording and playback Problems needing attention […]

  • Clickhouse transaction implementation of open source real-time data warehouse solution based on EMR OLAP


    Introduction: Alibaba cloud EMR OLAP cooperates deeply with Flink team and supports the exact once writing from Flink to Clickhouse to ensure the accuracy of the whole real-time warehouse data. This paper introduces the open source real-time data warehouse solution based on EMR OLAP. Introduction to the author Alibaba cloud emr-olap team; Mainly responsible for […]

  • Flink checkpoint mechanism and state management


    1 checkpoint mechanism 1.1 CheckPoints In order to make the state of Flink have good fault tolerance, Flink provides a checkpoint mechanism. Through the checkpoint mechanism, Flink periodically generates a checkpoint barrier on the data stream. When an operator receives a barrier, it will generate a snapshot based on the current state, and then transfer […]

  • [Part 6] – Summary of B2B2C e-commerce technology of spring cloud live mall of GIT basic operation


    Git basic operationGit’s job is to create and save snapshots of your project and compare them with subsequent snapshots. This chapter describes the commands for creating and submitting snapshots of your project. Git commonly uses the following six commands: git clone, GIT push, GIT add, GIT commit, GIT checkout, and git pull, which will be […]

  • Do you really understand the two persistence mechanisms of redis?


    Redis provides two persistence mechanisms RDB and AOF RDB (redis database): RDB saves snapshot data before a certain point in time. Aof (append only file): it means that all command line records are completely persisted and saved as AOF files in the format of redis command request protocol Mixed persistence (after version 4.0): when AOF […]

  • How to reduce and handle deadlocks – Notes on MySQL 8.0 official documents (IV)


    Document version: 8.0Source:How to Minimize and Handle DeadlocksPrevious:Snapshot read and lock read This chapter introduces how to reduce the occurrence of deadlock and how to deal with it.Deadlock refers to the situation where different transactions cannot continue to execute because they hold the lock waiting for each other. Because both sides are waiting for the […]

  • Apache Flink fault tolerance mechanism


    Original address:flink-release-1.2 Data Streaming Fault Tolerance Introduce Apache Flink provides a fault-tolerant mechanism that can recover the data flow and apply it to a consistent state. Ensure that in case of failure, each record of the program will only act on the state once (exactly once), of course, it can also be degraded to at […]

  • Redis Volume 16 of interview eight part essay


    The official account of WeChat:Moon chat TechnologyFocus on choice“Star Mark”, heavy dry goods, first time delivery![if you think the article is helpful to you, welcomeFollow, watch, like and forward] Hello, I’m moon. redisAs our most commonly used memory database, you can find its shadow in many places, such as the storage of login information and […]

  • Multi version concurrency control (mvcc) of MySQL


    1、 Snapshot read and current read Snapshot read is a consistent and unlocked read, which is one of the core reasons for the high concurrency of InnoDB. Under the read committed transaction isolation level, consistent unlocked reading means that the latest snapshot data of the locked row is always read. Therefore, if other transactions modify […]