MongDB集群容灾方案步骤

栏目: 数据库 · 发布时间: 6年前

内容简介：MongoDB复制集优/特点支持大数据量、高扩展性、高性能、灵活数据模型、高可用性。

MongoDB复制集

优/特点

支持大数据量、高扩展性、高性能、灵活数据模型、高可用性。

同步机制

数据复制的目的是使数据得到最大的可用性，避免单点故障引起的整站不能访问的情况的发生，Mongodb的副本集在同一时刻只有一台服务器是可以写的，副本集的主从复制也是一个异步同步的过程，是slave端从primary端获取日志，然后在自己身上完全顺序的执行日志所记录的各种操作（该日志是不记录查询操作的），这个日志就是local数据库中的oplog.rs表，默认在64位机器上这个表是比较大的，占磁盘大小的5%，oplog.rs的大小可以在启动参数中设定：--oplogSize 1000,单位是M。

鉴于双机房容灾意外情况可能放生，本方案选择故障时人工介入转移或恢复，不加入仲裁节点。其中A机房为主机房一个primary+2个Secondary节点，B机房作为灾备机房，2个Secondary节点。最坏当主机房挂掉时通过权重来启动B机房某节点为Primary，继续提供服务。

环境规划

A机房角色 B机房角色

192.168.70.214 Primary 192.168.71.214 Secondary 3 复制集节点 3

192.168.70.215 Secondary 1 复制集节点 1 192.168.71.215 Secondary 4 复制集节点 4

192.168.70.216 Secondary 2 复制集节点 2

架构示意图

其中下面是主机房断电断网时的故障转移示意图。

安装配置

这里所有节点目录创建一致，方便管理维护，从配置文件来判断各节点的角色。

创建目录

--为 MongoDB 创建软件、数据、日志目录，默认情况下它将数据存储在/mgdata

[root@test153 /]# mkdir -p /mgdb/mongodbtest/replset/data

[root@test153 /]# mkdir /mgdata

[root@test153 /]# mkdir /mglog

上传介质

sftp> cd /mgdb

sftp> put mongodb-linux-x86_64-2.2.3.tgz.tar

解压

[root@test153 /]# cd /mgdb

$ tar -xvf mongodb-linux-x86_64-2.2.3.tgz.tar

[root@test153 mgdb]# mv mongodb-linux-x86_64-2.2.3 mongodb

服务启动

每个节点都要执行

cd /root/mongodb/bin

192.168.70.214

/root/mongodb/bin/mongod --replSet repset --port 27017 --dbpath /root/data27011 --oplogSize 2048 --logpath /root/log27011/log27011.log &

./mongo 192.168.70.214:27017

192.168.70.215

/root/mongodb/bin/mongod --replSet repset --port 27017 --dbpath /root/data27012 --oplogSize 2048 --logpath /root/log27012/log27012.log &

./mongo 192.168.70.215:27017

192.168.70.216

/root/mongodb/bin/mongod --replSet repset --port 27017 --dbpath /root/data27013 --oplogSize 2048 --logpath /root/log27013/log27013.log &

./mongo 192.168.70.216:27017

192.168.71.214

/root/mongodb/bin/mongod --replSet repset --port 27017 --dbpath /root/data27017 --oplogSize 2048 --logpath /root/log27017/log27017.log &

./mongo 192.168.71.214:27017

192.168.71.215

/root/mongodb/bin/mongod --replSet repset --port 27017 --dbpath /root/data27018 --oplogSize 2048 --logpath /root/log27018/log27018.log &

./mongo 192.168.71.215:27017

分别通过 tail -f /root/log27011/log27011.log 来观察分析个节点运行情况

复制集配置

在任何一台mongodb实例上登录，进入admin库，执行config命令，配置相应权重

[root@localhost bin]# pwd

/root/mongodb/bin

[root@localhost bin]# ./mongo 192.168.70.214:27017

MongoDB shell version: 2.2.3

connecting to: test

Welcome to the MongoDB shell.

For interactive help, type "help".

For more comprehensive documentation, see

http://docs.mongodb.org/

Questions? Try the support group

http://groups.google.com/group/mongodb-user

> use admin

switched to db admin

> config = { _id:"repset", members:[

... {_id:0,host:"192.168.70.214:27017",priority:10},

... {_id:1,host:"192.168.70.215:27017",priority:7},

... {_id:2,host:"192.168.70.216:27017",priority:6},

... {_id:3,host:"192.168.71.214:27017",priority:9}]

... {_id:4,host:"192.168.71.215:27017",priority:8}]

... }

{

"_id" : "repset",

"members" : [

{

"_id" : 0,

"host" : "192.168.70.214:27017",

"priority" : 10

{

"_id" : 0,

"host" : "192.168.70.215:27017",

"priority" : 7

{

"_id" : 0,

"host" : "192.168.70.216:27017",

"priority" : 6

{

"_id" : 1,

"host" : "192.168.71.214:27017",

"priority" : 9

{

"_id" : 2,

"host" : "192.168.71.215:27017",

"priority" : 8

}

]

}

--查看

repset:PRIMARY> rs.conf()

{

"_id" : "repset",

"version" : 38349,

"members" : [

{

"_id" : 4,

"host" : "192.168.71.214:27017",

"priority" : 9

{

"_id" : 5,

"host" : "192.168.71.215:27017",

"priority" : 8

{

"_id" : 6,

"host" : "192.168.70.214:27017",

"priority" : 10

{

"_id" : 7,

"host" : "192.168.70.215:27017",

"priority" : 7

{

"_id" : 8,

"host" : "192.168.70.216:27017",

"priority" : 6

}

]

}

初始化副本集配置

> rs.initiate(config);

{

"info" : "Config now saved locally. Should come online in about a minute.",

"ok" : 1

}

初始需要一点时间同步

查看集群节点状态

repset:PRIMARY> rs.status()

{

"set" : "repset",

"date" : ISODate("2018-11-09T07:55:04Z"),

"myState" : 1,

"members" : [

{

"_id" : 4,

"name" : "192.168.71.214:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 1104,

"optime" : Timestamp(1541749003000, 1),

"optimeDate" : ISODate("2018-11-09T07:36:43Z"),

"lastHeartbeat" : ISODate("2018-11-09T07:55:03Z"),

"pingMs" : 0

{

"_id" : 5,

"name" : "192.168.71.215:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 1104,

"optime" : Timestamp(1541749003000, 1),

"optimeDate" : ISODate("2018-11-09T07:36:43Z"),

"lastHeartbeat" : ISODate("2018-11-09T07:55:03Z"),

"pingMs" : 0

{

"_id" : 6,

"name" : "192.168.70.214:27017",

"health" : 1,

"state" : 1,

"stateStr" : "PRIMARY",

"uptime" : 1680,

"optime" : Timestamp(1541749003000, 1),

"optimeDate" : ISODate("2018-11-09T07:36:43Z"),

"self" : true

{

"_id" : 7,

"name" : "192.168.70.215:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 1104,

"optime" : Timestamp(1541749003000, 1),

"optimeDate" : ISODate("2018-11-09T07:36:43Z"),

"lastHeartbeat" : ISODate("2018-11-09T07:55:03Z"),

"pingMs" : 0

{

"_id" : 8,

"name" : "192.168.70.216:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 1104,

"optime" : Timestamp(1541749003000, 1),

"optimeDate" : ISODate("2018-11-09T07:36:43Z"),

"lastHeartbeat" : ISODate("2018-11-09T07:55:03Z"),

"pingMs" : 0

}

"ok" : 1

}

repset:PRIMARY>

查看后台日志

[root@oracle_master ~]# tail -f /mgdata/mongodb/log27017/mongod.log

验证复制集数据一致性

先进去主库primary的mongodb上，录入数据

如

repset:PRIMARY> use dinpay

switched to db dinpay

repset:PRIMARY> db.dinpay.insert({"test1108":"xiawu1"})

repset:PRIMARY> db.getMongo().setSlaveOk();

去另一个备库上验证数据

repset:SECONDARY> db.dinpay.find()

{ "_id" : ObjectId("5bd676e97e238f7b0dddfb0d"), "MongoDB TEST" : "dinpay" }

{ "_id" : ObjectId("5bd823b65b237ec32e664db2"), "mdbtest" : "zgy20181030" }

{ "_id" : ObjectId("5be53e2c60074628c8509830"), "test1108" : "xiawu1" }

断电断网模拟

断电：直接kill mongdb进程

断网：开启某一机房的防火墙限制机房间通讯

B机房断电断网

192.168.71.214、192.16871.215断电断网后个节点状态

repset:PRIMARY> rs.status()

{

"set" : "repset",

"date" : ISODate("2018-11-09T08:02:36Z"),

"myState" : 1,

"members" : [

{

"_id" : 4,

"name" : "192.168.71.214:27017",

"health" : 0,

"state" : 8,

"stateStr" : "(not reachable/healthy)",

"uptime" : 0,

"optime" : Timestamp(1541750316000, 1),

"optimeDate" : ISODate("2018-11-09T07:58:36Z"),

"lastHeartbeat" : ISODate("2018-11-09T08:01:59Z"),

"pingMs" : 0,

"errmsg" : "socket exception [CONNECT_ERROR] for 192.168.71.214:27017"

{

"_id" : 5,

"name" : "192.168.71.215:27017",

"health" : 0,

"state" : 8,

"stateStr" : "(not reachable/healthy)",

"uptime" : 0,

"optime" : Timestamp(1541750316000, 1),

"optimeDate" : ISODate("2018-11-09T07:58:36Z"),

"lastHeartbeat" : ISODate("2018-11-09T08:01:57Z"),

"pingMs" : 0,

"errmsg" : "socket exception [CONNECT_ERROR] for 192.168.71.215:27017"

{

"_id" : 6,

"name" : "192.168.70.214:27017",

"health" : 1,

"state" : 1,

"stateStr" : "PRIMARY",

"uptime" : 2132,

"optime" : Timestamp(1541750316000, 1),

"optimeDate" : ISODate("2018-11-09T07:58:36Z"),

"self" : true

{

"_id" : 7,

"name" : "192.168.70.215:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 1556,

"optime" : Timestamp(1541750316000, 1),

"optimeDate" : ISODate("2018-11-09T07:58:36Z"),

"lastHeartbeat" : ISODate("2018-11-09T08:02:35Z"),

"pingMs" : 0

{

"_id" : 8,

"name" : "192.168.70.216:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 1556,

"optime" : Timestamp(1541750316000, 1),

"optimeDate" : ISODate("2018-11-09T07:58:36Z"),

"lastHeartbeat" : ISODate("2018-11-09T08:02:35Z"),

"pingMs" : 0

}

"ok" : 1

}

repset:PRIMARY>

结论：A机房运行正常。

A机房断电断网

192.168.70.214(PRI)、192.168.70.215、192.168.70.216

登录B机房任一台节点强制reconfig恢复副本集，仅保留活动着的节点

repset:SECONDARY> use admin

switched to db admin

--查看现有配置，其中70网段3个节点都已死掉了

repset:SECONDARY> cfg=rs.conf()

{

"_id" : "repset",

"version" : 79,

"members" : [

{

"_id" : 4,

"host" : "192.168.71.214:27017",

"priority" : 10

{

"_id" : 5,

"host" : "192.168.71.215:27017",

"priority" : 9

{

"_id" : 7,

"host" : "192.168.70.214:27017",

"priority" : 11

{

"_id" : 8,

"host" : "192.168.70.215:27017",

"priority" : 6

{

"_id" : 13,

"host" : "192.168.70.216:27017",

"priority" : 5

}

]

}

--只保留活着的节点

repset:SECONDARY> cfg.members = [cfg.members[0], cfg.members[1]]

[

{

"_id" : 4,

"host" : "192.168.71.214:27017",

"priority" : 10

{

"_id" : 5,

"host" : "192.168.71.215:27017",

"priority" : 9

}

]

--强制启动并新产生一个PRIMARY组成2节点的备份集

repset:SECONDARY> rs.reconfig(cfg, {force :true })

{ "ok" : 1 }

repset:SECONDARY> rs.status()

{

"set" : "repset",

"date" : ISODate("2018-11-09T03:45:29Z"),

"myState" : 1,

"members" : [

{

"_id" : 4,

"name" : "192.168.71.214:27017",

"health" : 1,

"state" : 1,

"stateStr" : "PRIMARY",

"uptime" : 69133,

"optime" : Timestamp(1541663971000, 1),

"optimeDate" : ISODate("2018-11-08T07:59:31Z"),

"self" : true

{

"_id" : 5,

"name" : "192.168.71.215:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 8,

"optime" : Timestamp(1541663971000, 1),

"optimeDate" : ISODate("2018-11-08T07:59:31Z"),

"lastHeartbeat" : ISODate("2018-11-09T03:45:29Z"),

"pingMs" : 0

}

"ok" : 1

}

repset:PRIMARY>

--检查数据，先前数据仍存在

repset:PRIMARY> use test

switched to db test

repset:PRIMARY> show collections

system.indexes

test

Testdb

--状态查询

repset:PRIMARY> rs.conf()

{

"_id" : "repset",

"version" : 38342,

"members" : [

{

"_id" : 4,

"host" : "192.168.71.214:27017",

"priority" : 10

{

"_id" : 5,

"host" : "192.168.71.215:27017",

"priority" : 9

}

]

}

结论：B机房强制启动，变成新的备份集

尽管已产生新的备份集，但不能保证断电断网瞬间存在旧PRIMARY未同步至各从节点而导致数据丢失的可能性。

恢复初始状态

Kill并重启A机房个节点mongdb

192.168.70.214

/root/mongodb/bin/mongod --replSet repset --port 27017 --dbpath /root/data27011 --oplogSize 2048 --logpath /root/log27011/log27011.log &

192.168.70.215

/root/mongodb/bin/mongod --replSet repset --port 27017 --dbpath /root/data27012 --oplogSize 2048 --logpath /root/log27012/log27012.log &

192.168.70.216

/root/mongodb/bin/mongod --replSet repset --port 27017 --dbpath /root/data27013 --oplogSize 2048 --logpath /root/log27013/log27013.log &

将A机房个节点加入新备份集（B机房），并对A机房某节点提权升为新的PRIMARY，恢复至断电断网前的状态

epset:PRIMARY> use admin

switched to db admin

repset:PRIMARY> cfg=rs.conf()

repset:PRIMARY> cfg.members[XX].priority = 8

repset:PRIMARY> rs.reconfig(cfg)

////////////////////////////////////////////////////////////////////////////////

主机房挂了再恢复测试。。。比上面恢复详细

--A机房(主机房) 192.168.70.214（主）/192.168.70.215/192.168.70.216断电断网，B机房强制重启后成为了新的集群，现在将2机房重新回到初始状态，首先要确认之前各节点都是什么角色

--加节点

--设权重

repset:PRIMARY> use admin

switched to db admin

repset:PRIMARY> rs.add("192.168.70.214:27017")

{ "ok" : 1 }

repset:PRIMARY> rs.add("192.168.70.215:27017")

{ "ok" : 1 }

repset:PRIMARY> rs.add("192.168.70.216:27017")

{ "ok" : 1 }

repset:PRIMARY>

repset:PRIMARY> cfg=rs.conf()

{

"_id" : "repset",

"version" : 63044,

"members" : [

{

"_id" : 4,

"host" : "192.168.71.214:27017",

"priority" : 9

{

"_id" : 5,

"host" : "192.168.71.215:27017",

"priority" : 8

{

"_id" : 6,

"host" : "192.168.70.214:27017"

{

"_id" : 7,

"host" : "192.168.70.215:27017"

{

"_id" : 8,

"host" : "192.168.70.216:27017"

}

]

}

repset:PRIMARY> cfg.members[2].priority = 11

repset:PRIMARY> cfg.members[3].priority = 6

repset:PRIMARY> cfg.members[4].priority = 5

repset:PRIMARY> rs.reconfig(cfg)

Mon Nov 12 16:04:10 DBClientCursor::init call() failed

Mon Nov 12 16:04:10 query failed : admin.$cmd { replSetReconfig: { _id: "repset", version: 63045, members: [ { _id: 4, host: "192.168.71.214:27017", priority: 9.0 }, { _id: 5, host: "192.168.71.215:27017", priority: 8.0 }, { _id: 6, host: "192.168.70.214:27017", priority: 11.0 }, { _id: 7, host: "192.168.70.215:27017", priority: 6.0 }, { _id: 8, host: "192.168.70.216:27017", priority: 5.0 } ] } } to: 192.168.71.214:27017

Mon Nov 12 16:04:10 trying reconnect to 192.168.71.214:27017

Mon Nov 12 16:04:10 reconnect 192.168.71.214:27017 ok

reconnected to server after rs command (which is normal)

repset:PRIMARY>

Mon Nov 12 16:04:29 Socket recv() errno:104 Connection reset by peer 192.168.71.214:27017

Mon Nov 12 16:04:29 SocketException: remote: 192.168.71.214:27017 error: 9001 socket exception [1] server [192.168.71.214:27017]

Mon Nov 12 16:04:29 DBClientCursor::init call() failed

Mon Nov 12 16:04:29 query failed : admin.$cmd { replSetGetStatus: 1.0, forShell: 1.0 } to: 192.168.71.214:27017

Mon Nov 12 16:04:37 trying reconnect to 192.168.71.214:27017

Mon Nov 12 16:04:37 reconnect 192.168.71.214:27017 ok

repset:SECONDARY>

repset:SECONDARY> rs.conf()

{

"_id" : "repset",

"version" : 63045,

"members" : [

{

"_id" : 4,

"host" : "192.168.71.214:27017",

"priority" : 9

{

"_id" : 5,

"host" : "192.168.71.215:27017",

"priority" : 8

{

"_id" : 6,

"host" : "192.168.70.214:27017",

"priority" : 11

{

"_id" : 7,

"host" : "192.168.70.215:27017",

"priority" : 6

{

"_id" : 8,

"host" : "192.168.70.216:27017",

"priority" : 5

}

]

}

repset:SECONDARY>

repset:SECONDARY> rs.status()

{

"set" : "repset",

"date" : ISODate("2018-11-12T08:05:16Z"),

"myState" : 2,

"syncingTo" : "192.168.70.214:27017",

"members" : [

{

"_id" : 4,

"name" : "192.168.71.214:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 19426,

"optime" : Timestamp(1542009850000, 1),

"optimeDate" : ISODate("2018-11-12T08:04:10Z"),

"errmsg" : "syncing to: 192.168.70.214:27017",

"self" : true

{

"_id" : 5,

"name" : "192.168.71.215:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 50,

"optime" : Timestamp(1542009850000, 1),

"optimeDate" : ISODate("2018-11-12T08:04:10Z"),

"lastHeartbeat" : ISODate("2018-11-12T08:05:14Z"),

"pingMs" : 0,

"errmsg" : "syncing to: 192.168.70.214:27017"

{

"_id" : 6,

"name" : "192.168.70.214:27017",

"health" : 1,

"state" : 1,

"stateStr" : "PRIMARY",

"uptime" : 64,

"optime" : Timestamp(1542009850000, 1),

"optimeDate" : ISODate("2018-11-12T08:04:10Z"),

"lastHeartbeat" : ISODate("2018-11-12T08:05:14Z"),

"pingMs" : 1

{

"_id" : 7,

"name" : "192.168.70.215:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 64,

"optime" : Timestamp(1542009850000, 1),

"optimeDate" : ISODate("2018-11-12T08:04:10Z"),

"lastHeartbeat" : ISODate("2018-11-12T08:05:14Z"),

"pingMs" : 0,

"errmsg" : "syncing to: 192.168.70.214:27017"

{

"_id" : 8,

"name" : "192.168.70.216:27017",

"health" : 1,

"state" : 2,

"stateStr" : "SECONDARY",

"uptime" : 64,

"optime" : Timestamp(1542009850000, 1),

"optimeDate" : ISODate("2018-11-12T08:04:10Z"),

"lastHeartbeat" : ISODate("2018-11-12T08:05:14Z"),

"pingMs" : 1,

"errmsg" : "syncing to: 192.168.70.214:27017"

}

"ok" : 1

}

repset:SECONDARY>

以上所述就是小编给大家介绍的《MongDB集群容灾方案步骤》，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对码农网的支持！

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Practical Django Projects, Second Edition

James Bennett / Apress / 2009 / 44.99

Build a django content management system, blog, and social networking site with James Bennett as he introduces version 1.1 of the popular Django framework. You’ll work through the development of ea......一起来看看《Practical Django Projects, Second Edition》这本书的介绍吧!

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Practical Django Projects, Second Edition

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