mongodb安装

mongodb3.2.8安装步骤：

1、系统准备

（1）redhat或cnetos6.2以上系统
（2）系统开发包完整
（3）ip地址和hosts文件解析正常
（4）iptables防火墙&SElinux关闭
（5）关闭大页内存机制

root用户下,vim /etc/rc.local最后添加如下代码
    if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
      echo never > /sys/kernel/mm/transparent_hugepage/enabled
    fi
    if test -f /sys/kernel/mm/transparent_hugepage/defrag; then
       echo never > /sys/kernel/mm/transparent_hugepage/defrag
    fi

其他系统关参照官方文档：

为什么要关闭？
Transparent Huge Pages (THP) is a Linux memory management system
that reduces the overhead of Translation Lookaside Buffer (TLB)
lookups on machines with large amounts of memory by using larger memory pages.
However, database workloads often perform poorly with THP,
because they tend to have sparse rather than contiguous memory access patterns.
You should disable THP on Linux machines to ensure best performance with MongoDB.

2、mongodb安装

2.1官方tarball安装

（1）创建所需用户和组

    groupadd -g 800  mongod&&useradd -u 801 -g mongod  
    echo "123456"|passwd --stdin  mongod

（2）创建mongodb所需目录结构

    mkdir -p /mongodb/{bin,conf,log,data}

（3）上传并解压软件到指定位置

mongodb-linux-x86_64-3.2.8.tgz 
解压源码包
cd mongodb-linux-x86_64-3.2.8/bin/  
cp * /mongodb/bin

（4）设置目录结构权限

    chown -R mongod:mongod /mongodb

（5）设置用户环境变量

su - mongod 
cat >> /home/.bash_profile <

（6）启动mongodb

mongod --dbpath=/mongodb/data --logpath=/mongodb/log/mongodb.log --port=27017 --logappend --fork

（7）登录mongodb

mongo
MongoDB shell version: 3.2.8
connecting to: test

（8）使用配置文件启动实例

mongod -f /mongodb/config/mongodb.conf

配置文件支持普通格式和yaml格式

普通格式如下:
cat >> /mongodb/config/mongodb.conf < logptah=
dbpath=
port=
logappend=
fork=
auth=
EOF

---

YAML模式如下：
NOTE：
YAML does not support tab characters for indentation: use spaces instead.

systemLog:  
destination: file  
  path: "/mongodb/log/mongod.log"  
  logAppend: true  
storage:  
  journal:  
    enabled: true  
  dbPath: ""
processManagement:
  fork: true
  pidFilePath: 
net:
  bindIp: 
  port: 
setParameter:
  enableLocalhostAuthBypass: false
security:
  authorization: enabled
  
replication:
  oplogSizeMB: 
  replSetName: ""
  secondaryIndexPrefetch: "all"
sharding:
  clusterRole: 
  archiveMovedChunks: 
---for mongos only
replication:
  localPingThresholdMs: 
sharding:
  configDB: 

（9）mongodb的关闭方式

kill进程形式 kill -2 PID
原理：-2表示向mongod进程发送SIGINT信号。
或 kill -4 PID
原理：-4表示向mognod进程发送SIGTERM信号。

---

自带模式
admin> db.shutdownServer()
或admin>db.adminCommand({shutdown:1}) 或$ mongod -f mongodb.conf --shutdown
注：mongod进程收到SIGINT信号或者SIGTERM信号，会做一些处理
关闭所有打开的连接
将内存数据强制刷新到磁盘
当前的操作执行完毕
安全停止

切忌kill -9

数据库直接关闭
数据丢失
数据文件损失
修复数据库（成本高，有风险）

2.2 使用官方yum源安装

参考官方文档
(1)加载官方yum源

cat > /etc/yum.repos.d/mongodb-org-4.0.repo <

(2)使用yum安装即可

yum install -y mongodb-org-4.0.1 mongodb-org-server-4.0.1 mongodb-org-shell-4.0.1 mongodb-org-mongos-4.0.1 mongodb-org-tools-4.0.1

3、mongodb控制脚本

    #!/bin/bash
    . /etc/init.d/functions
    Bin=/mongodb/bin
    port=28017
    start () {
      a=`whoami`
      if [ $a == root ];then
        for i in $port;do 
            su - mongod -c  "$Bin/mongod -f /mongodb/$i/conf/mongodb.conf"  &>/dev/null
            [ $? == 0 ] && action "${1} ${i}" /bin/true || action  "${1} ${i}" /bin/false
        done
      elif [ $a == mongod ];then
        for i in $port;do
            $Bin/mongod -f /mongodb/$i/conf/mongodb.conf  &>/dev/null
            [ $? == 0 ] && action "${1} ${i}" /bin/true || action  "${1} ${i}" /bin/false
        done
      else
        echo "permission denied!Only root & mongod can run this command!"
      fi
    }
    stop () {
      a=`whoami`
      if [ $a == root ];then
        for i in $port;do 
            su - mongod -c "$Bin/mongos -f /mongodb/$i/conf/mongodb.conf --shutdown" &>/dev/null
            [ $? == 0 ] && action "${1} ${i}" /bin/true || action "${1} ${i}" /bin/false
        done
      elif [ $a == mongod ];then
        for i in $port;do
            $Bin/mongos -f /mongodb/$i/conf/mongodb.conf --shutdown &>/dev/null
            [ $? == 0 ] && action "${1} ${i}" /bin/true || action "${1} ${i}" /bin/false
        done
      else
        echo "permission denied!Only root & mongod can run this command!"
      fi  
    }
    case $1 in 
      start)
      start
      ;;
      stop)
      stop
      ;;
      restart)
      stop
      sleep 2
      start
      ;;
      *)
      echo "Usage: $0 {start|stop|restart}"
      exit 1
    esac