Mongodb 逻辑结构                         MySQL逻辑结构
库database                                 库
集合（collection）                          表
文档（document）                            数据行

（1）redhat或centos6.2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
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root用户下
在vi /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
        
cat  /sys/kernel/mm/transparent_hugepage/enabled        
cat /sys/kernel/mm/transparent_hugepage/defrag  
其他系统关闭参照官方文档：   

https://docs.mongodb.com/manual/tutorial/transparent-huge-pages/
---------------
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.
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useradd mongod
passwd mongod

mkdir -p /mongodb/conf
mkdir -p /mongodb/log
mkdir -p /mongodb/data

chown -R mongod:mongod /mongodb

[root@db01 data]# cd   /data
[root@db01 data]# tar xf mongodb-linux-x86_64-rhel70-3.6.12.tgz 
[root@db01 data]#  cp -r /data/mongodb-linux-x86_64-rhel70-3.6.12/bin/ /mongodb

su - mongod
vi .bash_profile
export PATH=/mongodb/bin:$PATH
source .bash_profile

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

[mongod@server2 ~]$ mongo　　# 连接mongodb

YAML模式

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

--系统日志有关  
systemLog:
   destination: file        
   path: "/mongodb/log/mongodb.log"    --日志位置
   logAppend: true                     --日志以追加模式记录
  
--数据存储有关   
storage:
   journal:
      enabled: true
   dbPath: "/mongodb/data"            --数据路径的位置

-- 进程控制  
processManagement:
   fork: true                         --后台守护进程
   pidFilePath: <string>              --pid文件的位置，一般不用配置，可以去掉这行，自动生成到data中
    
--网络配置有关   
net:            
   bindIp: <ip>                       -- 监听地址
   port: <port>                       -- 端口号,默认不配置端口号，是27017
   
-- 安全验证有关配置      
security:
  authorization: enabled              --是否打开用户名密码验证
  
------------------以下是复制集与分片集群有关----------------------  

replication:
 oplogSizeMB: <NUM>
 replSetName: "<REPSETNAME>"
 secondaryIndexPrefetch: "all"
 
sharding:
   clusterRole: <string>
   archiveMovedChunks: <boolean>
      
---for mongos only
replication:
   localPingThresholdMs: <int>

sharding:
   configDB: <string>
---
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
YAML例子
cat >  /mongodb/conf/mongo.conf <<EOF
systemLog:
   destination: file
   path: "/mongodb/log/mongodb.log"
   logAppend: true
storage:
   journal:
      enabled: true
   dbPath: "/mongodb/data/"
processManagement:
   fork: true
net:
   port: 27017
   bindIp: 10.0.0.51,127.0.0.1
EOF
mongod -f /mongodb/conf/mongo.conf --shutdown　　# 关闭mongodb
mongod -f /mongodb/conf/mongo.conf   # 启动mongodb

mongod -f /mongodb/conf/mongo.conf --shutdown

[root@db01 ~]# cat > /etc/systemd/system/mongod.service <<EOF
[Unit]
Description=mongodb 
After=network.target remote-fs.target nss-lookup.target
[Service]
User=mongod
Type=forking
ExecStart=/mongodb/bin/mongod --config /mongodb/conf/mongo.conf
ExecReload=/bin/kill -s HUP $MAINPID
ExecStop=/mongodb/bin/mongod --config /mongodb/conf/mongo.conf --shutdown
PrivateTmp=true  
[Install]
WantedBy=multi-user.target
EOF

[root@db01 ~]# systemctl restart mongod
[root@db01 ~]# systemctl stop mongod
[root@db01 ~]# systemctl start mongod