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101,102 Machines haproxy settings 1. Unzip the file and enter the unzipped folder tar xvf haproxy-1.9.8.tar.gz cd haproxy-1.9.8 2. Compile and install haproxy, compile parameters make ARCH=x86_64 TARGET=linux2628 USE_PCRE=1 USE_OPENSSL=1 USE_ZLIB=1 USE_SYSTEMD=1 USE_CPU_AFFINITY=1 PREFIX=/usr/local/haproxy make install PREFIX=/usr/local/h ...

SETNX is an instruction in Redis, called "Set If Not Exist", which sets value to key only when it does not exist, otherwise no operation is performed. SETNX can also be used to implement locks in Redis. Problem introduction Before introducing how to use SETNX to implement locks, let's consider the following question: Suppose we now ha ...

Previously, I learned how to create a database tool class, as follows: import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class DBUtil { // Privatization Construction Method private DBUtil() { } private static String url = ""; ...

DDL, DML statements DDL (Data Definition Language) data definition language is to create, delete and modify the internal objects of the database; DML (Data manipulation language) is a data manipulation language, which operates on the data in the table. Create a database - CREATE Display the currently created database mysql> SHOW DATA ...

  MySQL triggers, like stored procedures, are a program embedded in MySQL.Triggers are actions triggered by time, including INSERT, UODATE, and DELETE statements.If triggers are defined, they trigger actions when the database executes these statements. A trigger is a named database object related to a table that is activated when a specifi ...

SELECT..FOR UPDATE has been extended in MySQL version 8.0 to implement new clauses NOWAIT and SKIP LOCKED ( WL#3597 and WL #8919 ).This is a simple try and see how it works.Finally, similar functionality in AliSQL is described below test Like the literal meaning of the new syntax, NOWAIT means that an error is returned directly when a lock cann ...

Linux install MySQL. 1. Installation Files mysql website I can't find how to download it.So, I upload to Baidu cloud for everyone Free Download. 2. Installation 1. Upload Files Use linux The sz and rz commands of can be uploaded, or can be uploaded using the filezila tool. After uploading, see the following file: ( ...

Get set First go to the official website https://www.zabbix.com/documentation/3.2/manual/installation/install_from_packages/repository_installation Here you install some trusted certificates, or components, based on your own system. In order to be able to use it quickly, I did not go into it. After the installation is completed, Now you a ...

Distributed MySql Deployment Scheme Solution System Environment mysql master-slave backup MyCat Middleware Build haproxy load agent keepalived for single point failure mycat-eye monitoring web Overall structure of experimental environment supplement Solution describe 1. Start mysql master-slave backup 2. Scheduling and routing using ...

What is FTWL FTWRL is short for FLUSH TABLES WITH READ LOCK (FTWRL). This command is mainly used to ensure backup consistency. In order to achieve this goal, it needs to close all table objects, so this command is very lethal and easy to cause hang when executing the command. If it is executed in the main library, the business cannot access it ...