How to add fields to mysql large tables without stopping

Adding fields to a table of ten million or more levels in MySQL has always been a headache. In this case, how to deal with it? This paper uses three common scenarios to illustrate the case. 1. Environmental preparation Database version: 5.7.25-28 (Percona branch) Server configuration: three centos 7 virtual machines with 2CPU 2G memory Database ...

Posted by romilbm on Fri, 19 Jun 2020 23:20:57 -0700

mysql master and slave of Liunx service management

Introduction of master and slave What is master-slave? MySQL master-slave replication is one of its most important functions. Master-slave replication refers to that one server acts as the master database server and another or more servers act as the slave database server, and the data in the master ...

Posted by grimz on Fri, 19 Jun 2020 05:48:13 -0700

Storage of real-time data, Spark+TDengine application in China Telecom Power Dynamometer System Monitoring Platform

Small T guide: the monitoring platform of electric power dynamometer system is designed and developed based on the equipment data acquisition and equipment Bank V2.0 application of China Telecom Shanghai ideal information industry (Group) Co., Ltd. The real-time data of the collected devices are stored in TDengine. Application background The p ...

Posted by ainoy31 on Thu, 18 Jun 2020 20:14:38 -0700

A quick tutorial of building server project based on Hunt Framework 3.2.0

Hunt Framework is a full stack Web framework developed in D language, similar to Laravel / SpringBoot / Django, etc., which enables D language developers to create projects quickly. The built-in super multi business specifications are convenient for developers to use out of the box, and convenient for managers to review project code more easily ...

Posted by jesse_james on Thu, 18 Jun 2020 02:11:58 -0700

2. Event monitoring and cluster building of zookeeper

1. zookeeper event listener 1.1. watcher concept: zookeeper provides data publish / subscribe function. Multiple subscribers can listen to a specific subject object at the same time. When the subject object's own state changes, such as the node content changes, the list of child nodes under the ...

Posted by brandtj on Thu, 18 Jun 2020 00:35:26 -0700

Practical tutorial of using JWT token in OAuth2.0 series

Practical tutorial of using JWT token in OAuth2.0 series (8) 1. Introduction to the preface 2. Example experiment verification 3. Simple function test OAuth2.0 blog series: Basic concepts and operation process of OAuth2.0 series (1) OAuth 2.0 series authorization code mode practice tutorial (2) O ...

Posted by jstarkey on Wed, 17 Jun 2020 00:18:06 -0700

Spring boot implements read-write separation (based on Mybatis, mysql)

Recently, the task is relatively light, and I have free time to learn learning technology, so I come to study how to realize the separation of reading and writing. Here we use blog to record the process. On the one hand, it can be viewed in the future, and on the other hand, it can also be shared with you (most of the information on the Interne ...

Posted by ctoshack on Tue, 16 Jun 2020 23:22:11 -0700

My development diary

Today, I mainly solved the verification of the login status of the test account. My current solution is to use the special syntax uid=123 when writing the test case, which means that the field of the use case should go to the login credentials of the test account with uid equal to 123. The difficulty is that the login credentials will expire an ...

Posted by tbach2 on Tue, 16 Jun 2020 21:49:56 -0700

Spring boot integrates redis trampling diary

In addition to providing excellent automatic testing for common relational databases, spring boot also provides automatic configuration support for many NoSQL databases, including redis, mongodb, elastic search, Solr and Cassandra. 01 integrate redis Redis is a very fast non relational database. It can store the mapping between key and five di ...

Posted by carrotcake1029 on Tue, 16 Jun 2020 21:16:33 -0700

Chapter 2 Introduction to MyBatis

Simple Edition Create a test table Create the corresponding JavaBean Create mybatis configuration file and sql mapping file test MyBatis operation database Create MyBatis global profile The global configuration file of MyBatis contains settings and properties information, such as database connection pool information, which affect MyBatis' ...

Posted by sumolotokai on Tue, 16 Jun 2020 20:27:06 -0700