So fragrant log dynamic level and output, are you sure not to come in and have a look? ——Dynamic input log level and file of production environment

This article is a series, welcome to update This article is full of energy. Please be prepared before eating. Please remember to like it after reading. Preface In the last article, we discussed the performance of the log and the advantages and disadvantages of the log. A friend said that I didn't have any dry goods, so I decided to have a dry ...

Posted on Thu, 16 Jan 2020 08:30:01 -0500 by strangermaster

Hand in hand to teach you MySQL query optimization analysis

Preface MySQL is a kind of relational database, which has strong query function, high data consistency, high data security and supports secondary index. However, the performance is slightly inferior to that of non relational databases, especially for data above one million levels, which is easy to cause slow query. At this time, we need to ana ...

Posted on Thu, 16 Jan 2020 02:02:29 -0500 by nuying117

Model & Form & model form

Model & Form & model form 1, Model & Form & modelform Model: used for user request data validation (weak pertinence), but with strong database operation Form: powerful data validation (for user request data) Model form: powerful data validation, moderate database operation. For data ...

Posted on Thu, 16 Jan 2020 01:34:29 -0500 by 3.grosz

MySQL Master-Slave Synchronization-Principle-Practice

What is mysql's master-slave replication? MySQL master-slave replication refers to the replication of data from one MySQL database server master node to one or more slave nodes.MySQL replicates asynchronously by default, so that the master server is not always accessed by the slave node to update its own data, which can be updated over a remote ...

Posted on Wed, 15 Jan 2020 20:55:58 -0500 by Cinquecento

Non relational redis database

Article directory redis introduction redis installation Redis built in data type redis application scenario Redis string common operations Redis list common operations This machine connects to the redis Library of another host python and redis redis introduction NoSQL(NoSQL = Not Only SQL), whic ...

Posted on Wed, 15 Jan 2020 07:41:01 -0500 by binto

Kafka use summary and production and consumption Demo implementation

What is kafka Kafka official website's own introduction is: a distributed flow platform can be supported.kafka official website kafka has three key capabilities: 1. Publish / subscribe record flow, similar to message queue and enterprise information system 2. Store the record stream in a fault-tolerant and persistent way 3. Con ...

Posted on Wed, 15 Jan 2020 07:25:05 -0500 by xydra

mybatis advanced query - one way query

Catalog I. demand Two, analysis Three, design 4, Mapper layer 5, Test code Six, thinking I. demand Query the detailed information of a user. In addition to the basic information of the user, it also includes the user's department and the user's role Two, analysis Users and departments: 1. ...

Posted on Wed, 15 Jan 2020 04:53:50 -0500 by phpdragon

Technology sharing | some MySQL DBA practical SQL statements

Author: Du Kaisheng Contents: 1, Connection related 2, Long affairs 3, Metadata lock 4, Lock wait 5, Global read lock 6, Memory usage monitoring 7, Partition table 8, Database information overview 9, Tables not updated for a long time 10, Primary key, index 11, Storage engine 12, Real time load Reading tips: 1) This article involves a lar ...

Posted on Wed, 15 Jan 2020 04:10:52 -0500 by johnsonzhang

pandas notes of data analysis

Pandas A content that represents a table type Lesson 4: jupyter21:22 Session 5: pandas 24:31 Session 6: series 38:19 Lesson 7: data framework 25:50 # Load pandas Library import pandas as pd import numpy as np s = pd.Series([2,4,6,8,10]) s 0 2 1 4 2 6 3 8 4 10 dtype: int64 d = p ...

Posted on Wed, 15 Jan 2020 01:33:57 -0500 by mtb211

CentOS 7.5 uses MySQL multi mode to install multiple instances of MySQL 5.7.28

Because the MySQL 5.7.28 multiple instances installed using the source code will have problems when importing the database, the method of using mysql_multi to manage multiple instances will be studied again. After the verification of the test environment, the problem of MySQL 5.7.28 multiple instances has not been reported in all aspects of us ...

Posted on Tue, 14 Jan 2020 21:19:22 -0500 by Anant