MongoDB高可用架构：Replica Sets+Sharding

MongoDB的sharding解决了海量存储和动态扩容的问题。但是遇到单点故障就显得无能为力了。MongoDB的副本集可以很好的解决单点故障的问题。所以就有了Sharding+Replica Sets的高可用架构了。

架构图如上所述

环境配置如下：

1：Shard服务器：使用Replica Sets确保每个数据节点的数据都有备份，自动容灾转移，自动恢复的能力。

2：Config服务器：使用3个配置服务器确保元数据完整性。

3：路由进程：使用3个路由进程实现平衡，提高客户端接入的性能。

4：6个分片进程：Shard A_1、Shard A_2、Shard A_3组成一个副本集Shard A。Shard B_1、Shard B_2

、Shard B_3组成另外一个副本集 Shard B。

Server	IP	进程以及端口
Server A	192.168.91.128	Mongod Shard A_1:27017 Mongod Shard B_1:27018 Mongod config:30000 Mongos:40000
Server B	192.168.91.129	Mongod Shard A_2:27017 Mongod Shard B_2:27018 Mongod config:30000 Mongos:40000
Server C	192.168.91.130	Mongod Shard A_3:27017 Mongod Shard B_3:27018 Mongod config:30000 Mongos:40000

1:在Server A上启动mongod Shard A_1

[root@localhost mongodb]# ./bin/mongod --shardsvr --replSet shard1 --port 27017 --dbpath ./data/servera --logpath ./log/loga/sharda1 --fork
about to fork child process, waiting until server is ready for connections.
forked process: 4838
child process started successfully, parent exiting

　　

在Server B上启动mongod Shard A_2

[root@localhost mongodb]# ./bin/mongod --shardsvr --replSet shard1 --port 27017 --dbpath ./data/servera --logpath ./log/loga/shardb1 --fork
about to fork child process, waiting until server is ready for connections.
forked process: 4540
child process started successfully, parent exiting

在Server C上启动mongod Shard A_3

[root@localhost mongodb]# ./bin/mongod --shardsvr --replSet shard1 --port 27017 --dbpath ./data/servera --logpath ./log/loga/shardc1 --fork
about to fork child process, waiting until server is ready for connections.
forked process: 4505
child process started successfully, parent exiting

　　

在3台服务器的任意一台上执行

[root@localhost mongodb]# ./bin/mongo
MongoDB shell version: 2.6.9
connecting to: test

> config={_id:"shard1",members:[
...  {_id:0,host:"192.168.91.128:27017"},
...  {_id:1,host:"192.168.91.129:27017"},
...  {_id:2,host:"192.168.91.130:27017"}
... ]}
{
	"_id" : "shard1",
	"members" : [
		{
			"_id" : 0,
			"host" : "192.168.91.128:27017"
		},
		{
			"_id" : 1,
			"host" : "192.168.91.129:27017"
		},
		{
			"_id" : 2,
			"host" : "192.168.91.130:27017"
		}
	]
}

> rs.initiate(config)
{
	"info" : "Config now saved locally.  Should come online in about a minute.",
	"ok" : 1
}

　　

2：在Server A上启动mongod Shard B_1

[root@localhost mongodb]# ./bin/mongod --shardsvr --replSet shard2 --port 27018 --dbpath ./data/serverb --logpath ./log/logb/shardb1 --fork
about to fork child process, waiting until server is ready for connections.
forked process: 5150
child process started successfully, parent exiting

在Server B上启动mongod Shard B_2

[root@localhost mongodb]# ./bin/mongod --shardsvr --replSet shard2 --port 27018 --dbpath ./data/serverb --logpath ./log/logb/shardb2 --fork
about to fork child process, waiting until server is ready for connections.
forked process: 4861
child process started successfully, parent exiting

在Server C上启动mongod Shard B_3

[root@localhost mongodb]# ./bin/mongod --shardsvr --replSet shard2 --port 27018 --dbpath ./data/serverb --logpath ./log/logb/shardb3 --fork
about to fork child process, waiting until server is ready for connections.
forked process: 4800
child process started successfully, parent exiting

　　

[root@localhost mongodb]# ./bin/mongo --port 27018
MongoDB shell version: 2.6.9
connecting to: 127.0.0.1:27018/test
> config={_id:"shard2",members:[
... ...  {_id:0,host:"192.168.91.128:27018"},
... ...  {_id:1,host:"192.168.91.129:27018"},
... ...  {_id:2,host:"192.168.91.130:27018"}
... ... ]}
{
	"_id" : "shard2",
	"members" : [
		{
			"_id" : 0,
			"host" : "192.168.91.128:27018"
		},
		{
			"_id" : 1,
			"host" : "192.168.91.129:27018"
		},
		{
			"_id" : 2,
			"host" : "192.168.91.130:27018"
		}
	]
}
> rs.initiate(config)
{
	"info" : "Config now saved locally.  Should come online in about a minute.",
	"ok" : 1
}

注意：

到这里可以检查A、B、C上的相应的监听服务是否正常？

[root@localhost mongodb]# netstat -nat | grep 2701

　　

副本集至此配置完毕。

3：分别在3台服务器上配置Config Server

在Server A上执行：

[root@localhost mongodb]# ./bin/mongod --port 30000 --dbpath ./data --logpath ./log/configlog --fork
about to fork child process, waiting until server is ready for connections.
forked process: 5430
child process started successfully, parent exiting

在Server B上执行：

[root@localhost mongodb]# ./bin/mongod --port 30000 --dbpath ./data --logpath ./log/configlog --fork
about to fork child process, waiting until server is ready for connections.
forked process: 5120
child process started successfully, parent exiting

在Server C上执行：

[root@localhost mongodb]# ./bin/mongod --port 30000 --dbpath ./data --logpath ./log/configlog --fork
about to fork child process, waiting until server is ready for connections.
forked process: 5056
child process started successfully, parent exiting

　　

4：配置Route Process

在Server A上执行：

[root@localhost mongodb]# ./bin/mongos --configdb 192.168.91.128:30000,192.168.91.129:30000,192.168.91.130:30000 --port 40000 --logpath ./log/route.log --chunkSize 1 --fork
about to fork child process, waiting until server is ready for connections.
forked process: 5596
child process started successfully, parent exiting

chunkSize ：指定chunk的大小，默认为200M。为了方便测试指定为1M。意思是当这个分片中插入的数据大于1M时候开始数据转移。

5：配置分片的表和片键

[root@localhost mongodb]# ./bin/mongo --port 40000
MongoDB shell version: 2.6.9
connecting to: 127.0.0.1:40000/test
mongos> use admin
switched to db admin
mongos> db.runCommand({addshard:"shard1/192.168.91.128:27017,192.168.91.129:27017,192.168.91.130:27017})
2015-05-06T00:38:37.360-0700 SyntaxError: Unexpected token ILLEGAL
mongos> db.runCommand({addshard:"shard1/192.168.91.128:27017,192.168.91.129:27017,192.168.91.130:27017"})
{ "shardAdded" : "shard1", "ok" : 1 }
mongos> db.runCommand({addshard:"shard2/192.168.91.128:27018,192.168.91.129:27018,192.168.91.130:27018"})
{ "shardAdded" : "shard2", "ok" : 1 }

　　

mongos> db.person.insert({"uid":1,"uname":"gechong","tel":"158"})
WriteResult({ "nInserted" : 1 })
mongos> db.runCommand({enablesharding:"person"})
{ "ok" : 1 }
mongos> db.runCommand({shardcollection:"person.per",key:{_id:1}})
{ "collectionsharded" : "person.per", "ok" : 1 }

使用person库的per集合来做分片。片键是_id.

至此整个架构已经部署完毕。