我们这里讲解的是如何配置mongodb复制集，首先在每一个机器上面安装mongodb，我们是通过yum的方式安装mongodb3.2
1.在文章中添加yum安装的配置文件：
touch /etc/yum.repos.d/mongodb-org-3.2.repo
vim /etc/yum.repos.d/mongodb-org-3.2.repo
打开文件后里面添加内容：
[mongodb-org-3.2]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.2/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-3.2.asc
2.yum安装
sudo yum install -y mongodb-org
其他节点也进行进行上面的步骤，将其他的节点按照上面，进行安装mongodb，安装完成后，都关闭mongodb：
sudo service mongod stop
3. 在每一个mongodb的节点，修改hosts
节点：192.168.220.105 mongo0.example.com
节点：192.168.220.106 mongo1.example.com
vim /etc/hosts
192.168.220.105：在上面打开的文件中添加或修改：
127.0.0.1 localhost mongo0.example.com
192.168.220.105 mongo0.example.com
192.168.220.106 mongo1.example.com
192.168.220.106：在上面文件中添加或者修改：
127.0.0.1 localhost mongo1.example.com
192.168.220.105 mongo0.example.com
192.168.220.106 mongo1.example.com
4. 在每一个mongodb的节点，修改hostname
节点：192.168.220.105 mongo0.example.com
节点：192.168.220.106 mongo1.example.com
192.168.220.105:
sudo hostname mongo0.example.com
vim /etc/hostname
#在打开的文件中添加：
mongo0.example.com
192.168.220.106:
sudo hostname mongo1.example.com
vim /etc/hostname
mongo1.example.com
5.修改mongodb的配置 vim /etc/mongod.conf
进行的修改为： 把bingIp注释掉，因为这一行只让本地访问：
net:
port: 27017
# bindIp: 127.0.0.1 # Listen to local interface only, comment to listen on all interfaces.
添加复制集配置：
replication:
replSetName: rs0
编辑完的内容为：
# mongod.conf
# for documentation of all options, see:
# http://docs.mongodb.org/manual/reference/configuration-options/
# where to write logging data.
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod.log
# Where and how to store data.
storage:
dbPath: /var/lib/mongo
journal:
enabled: true
# engine:
# mmapv1:
# wiredTiger:
# how the process runs
processManagement:
fork: true # fork and run in background
pidFilePath: /var/run/mongodb/mongod.pid # location of pidfile
# network interfaces
net:
port: 27017
# bindIp: 127.0.0.1 # Listen to local interface only, comment to listen on all interfaces.
#security:
#operationProfiling:
replication:
replSetName: rs0
#sharding:
## Enterprise-Only Options
#auditLog:
#snmp:
保存文件后，重启linxu。
添加开机启动
chkconfig mongod on
启动mongodb：
/etc/init.d/mongod restart
8.现在有两台linux，现在开始配置，注意，只能进入一台mongodb，其他的mongdb不要配置，启动就好。
在mongo0中：（这个作为主节点）
mongo
执行log如下：
[root@mongo0 ~]# mongo
MongoDB shell version: 3.2.7
connecting to: test
Server has startup warnings:
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten]
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten]
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten]
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 1024 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.
2016-06-20T14:10:48.876+0800 I CONTROL [initandlisten]
然后初始化：（注意，从节点不要执行rs.initiate() , 只有主节点执行这个）
rs.initiate()
log如下：
rs.initiate()
{
"info2" : "no configuration specified. Using a default configuration for the set",
"me" : "mongo0.example.com:27017",
"ok" : 1
}
rs0:OTHER>
增加节点：（在主节点中执行，添加从节点，主要从节点的iptables要添加信任，如果是本地，则可以直接关掉iptables，最好是添加ip信任，添加ip信任的方式
/sbin/iptables -I INPUT -p tcp --dport 27017 -j ACCEPT
/etc/rc.d/init.d/iptables save
）
rs0:OTHER> rs.add("mongo1.example.com:27017");
{ "ok" : 1 }
rs.config() 查看配置，log如下：
rs0:PRIMARY> rs.config();
{
"_id" : "rs0",
"version" : 2,
"protocolVersion" : NumberLong(1),
"members" : [
{
"_id" : 0,
"host" : "mongo0.example.com:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 1,
"host" : "mongo1.example.com:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("5767896cd1595b8f30b7cd4a")
}
}
查看状态：
rs0:PRIMARY> rs.status()
如果后续添加节点，那么，安装完mongodb，设置完成mongodb后，启动mongodb后，设置完成hosts后，直接在主节点中执行添加：
执行log如下：
rs0:PRIMARY> rs.add("mongo2.example.com:27017");
{ "ok" : 1 }
rs0:PRIMARY> rs.status
function () {
return db._adminCommand("replSetGetStatus");
}
rs0:PRIMARY> rs.status();
{
"set" : "rs0",
"date" : ISODate("2016-10-08T02:45:54.068Z"),
"myState" : 1,
"term" : NumberLong(19),
"heartbeatIntervalMillis" : NumberLong(2000),
"members" : [
{
"_id" : 0,
"name" : "mongo0.example.com:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 1126,
"optime" : {
"ts" : Timestamp(1475894744, 1),
"t" : NumberLong(19)
},
"optimeDate" : ISODate("2016-10-08T02:45:44Z"),
"electionTime" : Timestamp(1475894303, 1),
"electionDate" : ISODate("2016-10-08T02:38:23Z"),
"configVersion" : 3,
"self" : true
},
{
"_id" : 1,
"name" : "mongo1.example.com:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 617,
"optime" : {
"ts" : Timestamp(1475894744, 1),
"t" : NumberLong(19)
},
"optimeDate" : ISODate("2016-10-08T02:45:44Z"),
"lastHeartbeat" : ISODate("2016-10-08T02:45:52.842Z"),
"lastHeartbeatRecv" : ISODate("2016-10-08T02:45:52.847Z"),
"pingMs" : NumberLong(0),
"syncingTo" : "mongo0.example.com:27017",
"configVersion" : 3
},
{
"_id" : 2,
"name" : "mongo2.example.com:27017",
"health" : 0,
"state" : 8,
"stateStr" : "(not reachable/healthy)",
"uptime" : 0,
"optime" : {
"ts" : Timestamp(0, 0),
"t" : NumberLong(-1)
},
"optimeDate" : ISODate("1970-01-01T00:00:00Z"),
"lastHeartbeat" : ISODate("2016-10-08T02:45:52.842Z"),
"lastHeartbeatRecv" : ISODate("1970-01-01T00:00:00Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "No route to host",
"configVersion" : -1
}
],
"ok" : 1
}
rs0:PRIMARY>
日志：
rs0:PRIMARY> rs.status()
{
"set" : "rs0",
"date" : ISODate("2016-06-20T06:14:17.377Z"),
"myState" : 1,
"term" : NumberLong(1),
"heartbeatIntervalMillis" : NumberLong(2000),
"members" : [
{
"_id" : 0,
"name" : "mongo0.example.com:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 92,
"optime" : {
"ts" : Timestamp(1466403201, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2016-06-20T06:13:21Z"),
"infoMessage" : "could not find member to sync from",
"electionTime" : Timestamp(1466403181, 1),
"electionDate" : ISODate("2016-06-20T06:13:01Z"),
"configVersion" : 2,
"self" : true
},
{
"_id" : 1,
"name" : "mongo1.example.com:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 55,
"optime" : {
"ts" : Timestamp(1466403201, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2016-06-20T06:13:21Z"),
"lastHeartbeat" : ISODate("2016-06-20T06:14:15.784Z"),
"lastHeartbeatRecv" : ISODate("2016-06-20T06:14:14.010Z"),
"pingMs" : NumberLong(0),
"configVersion" : 2
}
],
"ok" : 1
}
如果连接的机器是另外一个机器，也就说不是mongodb复制集中的机器，需要添加host（此处需要说明的是php，如果是和mongodb分开的那么需要在php机器的hosts中添加hosts）
vim /etc/hosts
192.168.220.105 mongo0.example.com
192.168.220.106 mongo1.example.com
在shell 下面链接：（test是数据库的名字，rs0是复制集的名字）
mongo --host rs0/mongo0.example.com:27017,mongo1.example.com:27017 test
在php中连接：
'dsn' => 'mongodb://192.168.220.105:27017/erp,192.168.220.106:27017/erp?replicaSet=rs0&readPreference=primaryPreferred',
备份：
mongodump -h 192.168.220.60:27500 -d erp -o /terry/erp
恢复：
mongorestore -h 192.168.220.105:27017 -d erp /terry/erp
如果在配置复制集过程中出现了问题，无法进行，一般是想重新配置，但有一种比较好的办法，就是删除掉dbPath，在配置文件中dbPath的配置如下：
dbPath: /var/lib/mongo
rm -rf /var/lib/mongo/*
其他：
1. 删除mongodb的库，重新启动
mv /var/lib/mongo /var/lib/mongo1
mkdir /var/lib/mongo
chown mongod:mongod /var/lib/mongo
2.删除复制集节点：
rs.remove("mongo0.example.com:27017")
3.在副本集的副节点读数据：
db.setSlaveOk()
4.主从切换
进入主mongo 执行：
rs.stepDown(15);
log如下：
rs0:PRIMARY> rs.stepDown(15);
2016-10-08T10:37:25.511+0800 E QUERY [thread1] Error: error doing query: failed: network error while attempting to run command 'replSetStepDown' on host '127.0.0.1:27017' :
DB.prototype.runCommand@src/mongo/shell/db.js:135:1
DB.prototype.adminCommand@src/mongo/shell/db.js:153:16
rs.stepDown@src/mongo/shell/utils.js:1181:12
@(shell):1:1
2016-10-08T10:37:25.513+0800 I NETWORK [thread1] trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed
2016-10-08T10:37:25.525+0800 I NETWORK [thread1] reconnect 127.0.0.1:27017 (127.0.0.1) ok
rs0:SECONDARY>
rs0:SECONDARY>
rs0:SECONDARY>
rs0:SECONDARY>
rs0:SECONDARY>
参考：
https://gist.github.com/leommoore/309de7c0042ed697ee84
https://docs.mongodb.com/manual/tutorial/install-mongodb-on-red-hat/
https://docs.mongodb.com/manual/tutorial/deploy-replica-set/
https://docs.mongodb.com/manual/reference/configuration-options/