一 安装

1.1 下载MongoDB

我个人不太喜欢用wget url, 之前出现过wget下载的包有问题的情况

https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-3.4.7.tgz

1.2 上传服务器并解压

tar -zxvf mongodb-linux-x86_64-3.4.7.tgz 

1.3 移动到/data/program/software/mongodb

mv mongodb-linux-x86_64-3.4.7/ /data/program/software/mongodb

1.4 进入到mongodb目录下

mkdir dbmkdir logs

1.5 进入到bin目录下

新建配置文件:touch mongodb.conf

dbpath=/data/program/software/mongodb/dblogpath=/data/program/software/mongodb/logs/mongodb.logport=27017fork=truenohttpinterface=true

1.6 启动

分别在三台机器上启动

/data/program/software/mongodb/bin/mongod --replSet repset -f /data/program/software/mongodb/bin/mongodb.conf

1.7 查看是否启动成功

ps -ef |grep mongodb

1.8 建立集群

1.8.1 登录客户端

选择以上任意一台服务器登录客户端

/data/program/software/mongodb/bin/mongo

1.8.2 切换到admin数据库

use admin

1.8.3 建立集群

定义副本集配置变量，这里的_id:"repset"和上面命理参数--replSet repset保持一致

config={_id:"repset", members:[{_id:0,host:"132.232.47.139"},{_id:1,host:"45.40.199.46"},{_id:2,host:"132.232.40.31"}]}

输入以上变量后输入下面内容说明没问题

rs.initiate(config)

执行上面语句，如果输出下面内容说明没问题

1.8.5 查看集群状态

rs.status()

{ "set" : "repset", "date" : ISODate("2018-08-05T12:20:02.096Z"), "myState" : 1, "term" : NumberLong(1), "heartbeatIntervalMillis" : NumberLong(2000), "optimes" : { "lastCommittedOpTime" : { "ts" : Timestamp(1533471594, 1), "t" : NumberLong(1) }, "appliedOpTime" : { "ts" : Timestamp(1533471594, 1), "t" : NumberLong(1) }, "durableOpTime" : { "ts" : Timestamp(1533471594, 1), "t" : NumberLong(1) } }, "members" : [ { "_id" : 0, "name" : "132.232.47.139:27017", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "uptime" : 4360, "optime" : { "ts" : Timestamp(1533471594, 1), "t" : NumberLong(1) }, "optimeDate" : ISODate("2018-08-05T12:19:54Z"), "infoMessage" : "could not find member to sync from", "electionTime" : Timestamp(1533471513, 1), "electionDate" : ISODate("2018-08-05T12:18:33Z"), "configVersion" : 1, "self" : true }, { "_id" : 1, "name" : "45.40.199.46:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 100, "optime" : { "ts" : Timestamp(1533471594, 1), "t" : NumberLong(1) }, "optimeDurable" : { "ts" : Timestamp(1533471594, 1), "t" : NumberLong(1) }, "optimeDate" : ISODate("2018-08-05T12:19:54Z"), "optimeDurableDate" : ISODate("2018-08-05T12:19:54Z"), "lastHeartbeat" : ISODate("2018-08-05T12:20:01.211Z"), "lastHeartbeatRecv" : ISODate("2018-08-05T12:20:01.767Z"), "pingMs" : NumberLong(0), "syncingTo" : "132.232.47.139:27017", "configVersion" : 1 }, { "_id" : 2, "name" : "132.232.40.31:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 100, "optime" : { "ts" : Timestamp(1533471594, 1), "t" : NumberLong(1) }, "optimeDurable" : { "ts" : Timestamp(1533471594, 1), "t" : NumberLong(1) }, "optimeDate" : ISODate("2018-08-05T12:19:54Z"), "optimeDurableDate" : ISODate("2018-08-05T12:19:54Z"), "lastHeartbeat" : ISODate("2018-08-05T12:20:01.211Z"), "lastHeartbeatRecv" : ISODate("2018-08-05T12:20:01.769Z"), "pingMs" : NumberLong(0), "syncingTo" : "132.232.47.139:27017", "configVersion" : 1 } ], "ok" : 1}

1.8.6 测试集群功能

a 主节点服务器登录客户端

./mongo

b 连接test数据库

use test

c 往testdb表中插入数据

db.testdb.insert({"test1":"testval1"})

d 连接到副本节点客户端

./mongo 45.40.199.46:27017

e 使用test数据库

use test

f 查询表格

show tables

如果出现以下报错

mongodb默认是从主节点读写数据，副本节点上不允许读，设置副本节点可读

g 设置读权限

db.getMongo().setSlaveOk()

h 查询在主节点上插入的数据

db.testdb.find()

i 测试集群恢复功能

1 将主节点服务停掉后在登录其他节点客户端查看集群状态

{ "set" : "repset", "date" : ISODate("2018-08-05T13:15:05.136Z"), "myState" : 1, "term" : NumberLong(2), "heartbeatIntervalMillis" : NumberLong(2000), "optimes" : { "lastCommittedOpTime" : { "ts" : Timestamp(1533474896, 1), "t" : NumberLong(2) }, "appliedOpTime" : { "ts" : Timestamp(1533474896, 1), "t" : NumberLong(2) }, "durableOpTime" : { "ts" : Timestamp(1533474896, 1), "t" : NumberLong(2) } }, "members" : [ { "_id" : 0, "name" : "132.232.47.139:27017", "health" : 0, "state" : 8, "stateStr" : "(not reachable/healthy)", "uptime" : 0, "optime" : { "ts" : Timestamp(0, 0), "t" : NumberLong(-1) }, "optimeDurable" : { "ts" : Timestamp(0, 0), "t" : NumberLong(-1) }, "optimeDate" : ISODate("1970-01-01T00:00:00Z"), "optimeDurableDate" : ISODate("1970-01-01T00:00:00Z"), "lastHeartbeat" : ISODate("2018-08-05T13:15:03.341Z"), "lastHeartbeatRecv" : ISODate("2018-08-05T13:12:24.585Z"), "pingMs" : NumberLong(0), "lastHeartbeatMessage" : "Connection refused", "configVersion" : -1 }, { "_id" : 1, "name" : "45.40.199.46:27017", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "uptime" : 7653, "optime" : { "ts" : Timestamp(1533474896, 1), "t" : NumberLong(2) }, "optimeDate" : ISODate("2018-08-05T13:14:56Z"), "electionTime" : Timestamp(1533474755, 1), "electionDate" : ISODate("2018-08-05T13:12:35Z"), "configVersion" : 1, "self" : true }, { "_id" : 2, "name" : "132.232.40.31:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 3401, "optime" : { "ts" : Timestamp(1533474896, 1), "t" : NumberLong(2) }, "optimeDurable" : { "ts" : Timestamp(1533474896, 1), "t" : NumberLong(2) }, "optimeDate" : ISODate("2018-08-05T13:14:56Z"), "optimeDurableDate" : ISODate("2018-08-05T13:14:56Z"), "lastHeartbeat" : ISODate("2018-08-05T13:15:03.282Z"), "lastHeartbeatRecv" : ISODate("2018-08-05T13:15:03.165Z"), "pingMs" : NumberLong(0), "syncingTo" : "45.40.199.46:27017", "configVersion" : 1 } ], "ok" : 1}

结论:_id=1的服务现在变成了主节点，_id=0的服务现在不可用了

2 再次将原来的132.232.47.139这台机器启动起来

{ "set" : "repset", "date" : ISODate("2018-08-05T13:19:08.073Z"), "myState" : 1, "term" : NumberLong(2), "heartbeatIntervalMillis" : NumberLong(2000), "optimes" : { "lastCommittedOpTime" : { "ts" : Timestamp(1533475146, 1), "t" : NumberLong(2) }, "appliedOpTime" : { "ts" : Timestamp(1533475146, 1), "t" : NumberLong(2) }, "durableOpTime" : { "ts" : Timestamp(1533475146, 1), "t" : NumberLong(2) } }, "members" : [ { "_id" : 0, "name" : "132.232.47.139:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 4, "optime" : { "ts" : Timestamp(1533474744, 1), "t" : NumberLong(1) }, "optimeDurable" : { "ts" : Timestamp(1533474744, 1), "t" : NumberLong(1) }, "optimeDate" : ISODate("2018-08-05T13:12:24Z"), "optimeDurableDate" : ISODate("2018-08-05T13:12:24Z"), "lastHeartbeat" : ISODate("2018-08-05T13:19:07.545Z"), "lastHeartbeatRecv" : ISODate("2018-08-05T13:19:03.326Z"), "pingMs" : NumberLong(0), "configVersion" : 1 }, { "_id" : 1, "name" : "45.40.199.46:27017", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "uptime" : 7896, "optime" : { "ts" : Timestamp(1533475146, 1), "t" : NumberLong(2) }, "optimeDate" : ISODate("2018-08-05T13:19:06Z"), "electionTime" : Timestamp(1533474755, 1), "electionDate" : ISODate("2018-08-05T13:12:35Z"), "configVersion" : 1, "self" : true }, { "_id" : 2, "name" : "132.232.40.31:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 3644, "optime" : { "ts" : Timestamp(1533475146, 1), "t" : NumberLong(2) }, "optimeDurable" : { "ts" : Timestamp(1533475146, 1), "t" : NumberLong(2) }, "optimeDate" : ISODate("2018-08-05T13:19:06Z"), "optimeDurableDate" : ISODate("2018-08-05T13:19:06Z"), "lastHeartbeat" : ISODate("2018-08-05T13:19:07.360Z"), "lastHeartbeatRecv" : ISODate("2018-08-05T13:19:07.255Z"), "pingMs" : NumberLong(0), "syncingTo" : "45.40.199.46:27017", "configVersion" : 1 } ], "ok" : 1}

结论：_id=1的这个服务还是主节点，_id=0的服务变成了副本节点