MongoDB集群搭建
MongoDB的复制集群类型：
·主从模式(master/slave)
·副本集模式（replica set）
副本及模式至少3个节点（一主二从），从节点负责复制主节点的oplog到本地并且应用到本地从而实现冗余。
（·arbiter：仅参与选举，但不持有任何数据
·0优先级：可以触发选举，但是不能被选举成为主节点
·可以使用repiset来定义集群名称）
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相关阅读：
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1.编译安装MongDB
准备环境：
系统：Debian 7.2 64位
mongodb：mongodb-linux-x86_64-2.4.5.tgz（官网有下）
root@namenode1:/usr/local/tools# tar xfmongodb-linux-x86_64-2.4.5.tgz
root@namenode1:/usr/local/tools# mv mongodb-linux-x86_64-2.4.5 /usr/local/
root@namenode1:/usr/local/tools# cd /usr/local/
root@namenode1:/usr/local# ln -s /usr/local/mongodb-linux-x86_64-2.4.5//usr/local/mongodb
root@namenode1:/usr/local# ll | grep mongo
lrwxrwxrwx 1 root staff 38 3月 17 15:35 mongodb ->/usr/local/mongodb-linux-x86_64-2.4.5/
drwxr-sr-x 3 root staff 4096 3月 17 15:08 mongodb-linux-x86_64-2.4.5
#创建用户
root@namenode1:~# groupadd -r mongod
root@namenode1:~# useradd -M -r -g mongod -d /data/db -s /bin/false -c mongodmongod
#建立目录
root@namenode1:~# mkdir -p /var/log/mongo/
root@namenode1:~# mkdir -p /mongo/data
root@namenode1:~# chown mongod /mongo/data /var/log/mongo/
root@namenode1:~# ll /var/log/ | grep mongo
drwxr-xr-x 2mongod root 4096 Mar 17 15:25mongo
root@namenode1:~# ll /mongo/
total 4
drwxr-xr-x 2 mongod root 4096 Mar 17 15:27 data
#将LC_ALL="C"加入环境变量，以防启动出错
root@namenode1:~# echo ‘export LC_ALL="C"’ >> /etc/profile
#创建配置文件(将之前rpm包安装mongodb后的配置文件拷贝过来即可)
root@namenode1:~# cat /etc/mongod.conf
# mongo.conf
#where to log
logpath=/var/log/mongo/mongod.log
logappend=true
# fork and run in background
fork = true
#port = 27017
dbpath=/mongo/data
# location of pidfile
pidfilepath = /var/run/mongodb/mongod.pid
# Disables write-ahead journaling
# nojournal = true
# Enables periodic logging of CPU utilization and I/O wait
#cpu = true
# Turn on/off security. Off is currently the default
#noauth = true
#auth = true
# Verbose logging output.
#verbose = true
# Inspect all client data for validity on receipt (useful for
# developing drivers)
#objcheck = true
# Enable db quota management
#quota = true
# Set oplogging level where n is
# 0=off (default)
# 1=W
# 2=R
# 3=both
# 7=W+some reads
#diaglog = 0
# Ignore query hints
#nohints = true
# Disable the HTTP interface (Defaults to localhost:27018).
#nohttpinterface = true
# Turns off server-side scripting. This will result in greatly limited
# functionality
#noscripting = true
# Turns off table scans. Any query that would do a table scan fails.
#notablescan = true
# Disable data file preallocation.
#noprealloc = true
# Specify .ns file size for new databases.
# nssize =
# Accout token for Mongo monitoring server.
#mms-token =
# Server name for Mongo monitoring server.
#mms-name =
# Ping interval for Mongo monitoring server.
#mms-interval =
# Replication Options
# in replicated mongo databases, specify here whether this is a slave or master
#slave = true
#source = master.example.com
# Slave only: specify a single database to replicate
#only = master.example.com
# or
#master = true
#source = slave.example.com
启动mongodb
export LC_ALL="C"
root@namenode2:/usr/local/mongodb/bin# mongod -f /etc/mongod.conf
2.安装Rockmongo
RockMongo 是一个PHP5写的MongoDB管理工具。主要特征:使用宽松的New BSD License协议，速度快，安装简单，与mysql的phpmyadmin相似
root@namenode1:~# apt-get install apache2 php5 php5-dev php5-cli
root@namenode1:/etc/apache2# cd /var/www/
root@namenode