MongoDB的sharding功能（转）

时间：2010-10-21 来源：不得闲

[[email protected]  ~/mongodata]$ mkdir 27020 27021 27022
[[email protected]  ~/mongodata]$ ls
27020  27021  27022

[[email protected]  ~/mongodb/bin]$ ./mongod --dbpath /home/falcon/mongodata/27020 --port 27020 > /home/falcon/mongodata/27020.log &
[[email protected]  ~/mongodb/bin]$ ./mongod --dbpath /home/falcon/mongodata/27021 --port 27021  > /home/falcon/mongodata/27021.log &
[[email protected]  ~/mongodb/bin]$ ./mongod --dbpath /home/falcon/mongodata/27022 --port 27022  > /home/falcon/mongodata/27022.log &

启动mongos时，默认开启了27017端口

[[email protected] ~/mongodb/bin]$ ./mongos --configdb localhost:27022 > /home/falcon/mongodata/config.log &

检查是否启动

[[email protected]  ~/mongodb/bin]$ ps -ef|grep mongo
falcon 2612    1  0 20:15 ?       00:00:00 ./mongod --dbpath /home/falcon/mongodata/27020 --port 27020
falcon 2619    1  0 20:15 ?       00:00:00 ./mongod --dbpath /home/falcon/mongodata/27021 --port 27021
falcon 2625    1  0 20:15 ?       00:00:00 ./mongod --dbpath /home/falcon/mongodata/27022 --port 27022
falcon 2658    1  0 20:15 ?       00:00:00 ./mongos --configdb localhost:27022
falcon 2804  2772  0 20:31 pts/0 00:00:00 bin/mongo
falcon 2847  2812  0 20:55 pts/2 00:00:00 grep mongo
[[email protected]  ~/mongodb/bin]$

[[email protected]  ~/mongodb/bin]$ netstat -an  -t
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address             Foreign Address          State
tcp       0    0 0.0.0.0:10022             0.0.0.0:*                LISTEN
tcp       0    0 0.0.0.0:27017             0.0.0.0:*                LISTEN
tcp       0    0 0.0.0.0:587                0.0.0.0:*                LISTEN
tcp       0    0 0.0.0.0:27020             0.0.0.0:*                LISTEN
tcp       0    0 0.0.0.0:27021             0.0.0.0:*                LISTEN
tcp       0    0 0.0.0.0:27022             0.0.0.0:*                LISTEN
......
tcp       0    0 0.0.0.0:28020             0.0.0.0:*                LISTEN
tcp       0    0 0.0.0.0:28021             0.0.0.0:*                LISTEN
tcp       0    0 0.0.0.0:28022             0.0.0.0:*                LISTEN
tcp       0    0 127.0.0.1:631             0.0.0.0:*                LISTEN
........

看到以上信息证明mongodb启动完整，对于开启的28020、28021、28022是对于的http接口

[[email protected] ~/mongodb/bin]$ ./mongo 默认连接到mongos上
MongoDB shell version: 1.2.4-
url: test
connecting to: test
type "help" for help
> show dbs
admin
config
Local

加入shard节点

> use admin
switched to db admin

> db.runCommand( { addshard : "localhost:27020", allowLocal : true } )
{"ok" : 1 , "added" : "localhost:27020"}

> db.runCommand( { addshard : "localhost:27021", allowLocal : true } )
{"ok" : 1 , "added" : "localhost:27021"}

> db.runCommand({listshards:1}); 查看shard节点列表
{
      "shards" : [
               {
                     "_id" : ObjectId("4b9cd380c33000afad27718e"),
                     "host" : "localhost:27020"
               },
               {
                     "_id" : ObjectId("4b9cd381c33000afad27718f"),
                     "host" : "localhost:27021"
               }
      ],
      "ok" : 1
}

新建自动切片的库user001：

> config = connect("localhost:27022")
> config = config.getSisterDB("config")
> user001=db.getSisterDB("user001");
user001
> db.runCommand({enablesharding:"user001"})
{ "ok" : 1 }

> db.printShardingStatus();
--- Sharding Status ---
sharding version: { "_id" : ObjectId("4b9cd354c33000afad27718d"), "version" : 2 }
shards:
   { "_id" : ObjectId("4b9cd380c33000afad27718e"), "host" : "localhost:27020" }
   { "_id" : ObjectId("4b9cd381c33000afad27718f"), "host" : "localhost:27021" }
databases:
      { "name" : "admin", "partitioned" : false, "primary" : "localhost:27022", "_id" : ObjectId("4b9cd3776693dcfa468dec13") }
      { "name" : "user001", "partitioned" : true, "primary" : "localhost:27021", "_id" : ObjectId("4b9cde866693dcfa468dec17") }
               my chunks

我们来在user001中新建表，插入数据

> use user001
switched to db user001
> db.createCollection("user_001")
{ "ok" : 1 }
> show collections
system.indexes
user_001
> db.user_001.insert({uid:1,username:"Falcon.C",sex:"男",age:25});
> db.user_001.find();
{ "_id" : ObjectId("4b9ce1a6c84d7f20576c4df1"), "uid" : 1, "username" : "Falcon.C", "sex" : "男", "age" : 25 }

我们来看看user001库被分配到了哪个shard上

[[email protected]  ~/mongodata]$ ls -R
.:
27020  27021  27022  mongos.log

./27020:
27020.log  mongod.lock  test.0  test.1  test.ns  _tmp

./27020/_tmp:

./27021:
27021.log  mongod.lock  _tmp  user.0  user001.0  user001.1  user001.ns  user.1  user.ns

./27021/_tmp:

./27022:
27022.log  config.0  config.ns  mongod.lock  mongos.log  _tmp

./27022/_tmp:
[[email protected]  ~/mongodata]$

从以上的文件可以看出，user001被分配到了27021的shard上了，但是通过mongos路由，我们并感觉不到是数据存放在哪个shard的chunk上

Sharding的管理命令

> db.$cmd.findOne({isdbgrid:1});
{ "isdbgrid" : 1, "hostname" : "www.fwphp.cn", "ok" : 1 }
> db.$cmd.findOne({ismaster:1});
{ "ismaster" : 1, "msg" : "isdbgrid", "ok" : 1 }
> printShardingStatus(db.getSisterDB("config"))
--- Sharding Status ---
sharding version: { "_id" : ObjectId("4b9cd354c33000afad27718d"), "version" : 2 }
shards:
   { "_id" : ObjectId("4b9cd380c33000afad27718e"), "host" : "localhost:27020" }
   { "_id" : ObjectId("4b9cd381c33000afad27718f"), "host" : "localhost:27021" }
databases:
      { "name" : "admin", "partitioned" : false, "primary" : "localhost:27022", "_id" : ObjectId("4b9cd3776693dcfa468dec13") }
               my chunks
      { "name" : "user001", "partitioned" : true, "primary" : "localhost:27021", "_id" : ObjectId("4b9cde866693dcfa468dec17") }
               my chunks
> use admin
switched to db admin
> db.runCommand({netstat:1})
{ "configserver" : "localhost:27022", "isdbgrid" : 1, "ok" : 1 }
>

参考信息：http://www.mongodb.org/display/DOCS/Sharding