Garbage Priority Garbage Collector

Garbage Priority Garbage Collector (G1 GC) Use notes

G1 GC is a new garbage collection strategy, starting with JDK7, mainly for server-side JVM, and large memory applications, the goal is to achieve similar high-throughput CMS. G1 is still the idea of ??sub-management, the main use of the idea of ??block management, through the memory is […]

tomcat monitor script

#!/bin/bash echo $(date ‘+%Y-%m-%d %H:%M:%S’) whoami JAVA_HOME=/opt/java/jdk1.8.0_40 PATH=$JAVA_HOME/bin:$PATH export PATH JAVA_HOME port=8086 sn=“tomcat-image-$port“ th=“/home/dev/tomcat/$sn“ url=“http://you-app-server/” tomcat=`ps -ef | grep java | grep $sn | grep $port | wc -l` if [ $tomcat -eq 0 ] then echo $sn stoped. echo starting $sn …… $th/bin/ fi if [ $tomcat -ge 1 ] then tpid=`ps -ef | […]

How To Configure a Redis Cluster on CentOS 7

yum install gcc make cd ~ mkdir init wget tar -zxvf redis-3.2.3.tar.gz cd redis-3.2.3 make make install #cd utils #./ cd src/ cp redis-server redis-cli /usr/local/bin cp redis-sentinel redis-benchmark redis-check-aof redis-check-dump /usr/local/bin mkdir /etc/redis mkdir -p /var/lib/redis/6379

Set the vm.overcommit_memory to 1, which means always, this will avoid data to be truncated, take a […]

Realize MySQL database automatic backup under Linux

1.Linux under MySQL to create a user backup role, and granted the role of SELECT, RELOAD, SHOW DATABASES, LOCK TABLES and other permissions.


mysql> create user ‘backuper’@’localhost’ identified by ‘********’; Query OK, 0 rows affected (0.00 sec) mysql> grant SELECT, RELOAD, SHOW DATABASES, LOCK TABLES on *.* to backuper@localhost; Query OK, 0 rows affected […]

MySQL 5.7 forget the root password


CentOS 6.6 X86_64


Forget how to do root, forget to initialize MySQL generated when the random password how to do, or simply did not register that random password, do not tell me to clear all the data under data, reinitialize, of course, you have to be so wayward can also be. Do not pull, […]

MySQL 5.7 multi-instance installation deployment instance

1. Background MySQL database centralized operation and maintenance, through a server, the deployment of running multiple MySQL service process, through a different socket to monitor different service ports to provide their services. Each instance is independent of each other, each instance of the datadir, port, socket, pid are different.

2. Multi-instance features * Effective use of […]

CentOS 7 rpm installed under the MySQL 5.6.36

CentOS 7 under the local installation of MySQL 5.7, but the springboot integration jpa will appear hibernateException, do not know why, for a MySQL5.6 version of MySQL, source installation, cmake has been through, and later into rpm installation.

Local installation of mysql5.7, but the integration of springboot jpa will appear hibernateException, do not know why, for […]

MySQL index conditions push a simple test

Since MySQL 5.6, there have been some improvements in the index, such as the index condition pushdown (ICP), strictly speaking, the optimizer level improvement.

If it is simple to understand, that is, the optimizer will try to index the treatment from the Server layer to the storage engine layer. As an example, there is a table […]

Oracle backup script

Oracle backup script

#!/bin/bash version1.0 chmod 700 #00 00 * * * /usr/local/scripts/ #chmod 700 /usr/local/scripts/ #You must first import the environment variables in the Oracle user’s bash_profile file #Must be used to define the DBA account first dpdata1 path and authorized directory to read and write, modify the dpdata1 group

export ORACLE_BASE=/usr/local/u01/oracle […]

CentOS 7.2 Installation Deployment OpenStack Tutorial

CentOS 7.2 Installation Deployment OpenStack Tutorial

Environmental preparation


Share CentOS 7.2 installation deployment OpenStack tutorial, we want to help.

1, the system environment

# Uname -r


# Cat / etc / RedHat -release

CentOS Linux release 7.2.1511 (Core)

2, the server deployment


CPU name




Control node

M: 4G; […]

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