MongoDB数据库分片操作
集群概况
| 机器1 | 机器2 | 机器3 |
|---|---|---|
| 172.19.147.247 | 172.19.147.248 | 172.19.147.249 |
| mongos1:27000 | mongos2:27000 | mongos3:27000 |
| config1:27000 | config1:27000 | config1:27000 |
| shard1 master:27001 | shard1 secondary:27001 | shard1 arbiter:27001 |
| shard2 arbiter:27002 | shard2 master:27002 | shard2 secondary:27002 |
| shard3 secondary:27003 | shard3 arbiter:27003 | shard3 master:27003 |
一、进入MongoDB目录，连接
[root@cluster-1 /]# cd /data/mongodb/bin/
[root@cluster-1 bin]# ./mongo 172.19.147.247:27000
MongoDB shell version v4.2.7
connecting to: mongodb://172.19.147.247:27000/test?compressors=disabled&gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("d41801c0-37b1-4802-b2e6-c4a53345cff4") }
MongoDB server version: 4.2.7
Server has startup warnings:
2021-08-10T17:31:37.241+0800 I CONTROL [main]
2021-08-10T17:31:37.241+0800 I CONTROL [main] ** WARNING: Access control is not enabled for the database.
2021-08-10T17:31:37.241+0800 I CONTROL [main] ** Read and write access to data and configuration is unrestricted.
2021-08-10T17:31:37.241+0800 I CONTROL [main] ** WARNING: You are running this process as the root user, which is not recommended.
2021-08-10T17:31:37.241+0800 I CONTROL [main]
mongos>
二、新建数据库，新建表
mongos> use test
switched to db test
mongos> db.createCollection("table")
{
"ok" : 1,
"operationTime" : Timestamp(1628818042, 8),
"$clusterTime" : {
"clusterTime" : Timestamp(1628818042, 8),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
}
}
三、查看数据库当前情况
primary：数据库主分片在shard1上面
partitioned：false表示分片未开启
mongos> sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("611239f7d5eb662c357d1f8a")
}
shards:
{ "_id" : "shard1", "host" : "shard1/172.19.147.247:27001,172.19.147.248:27001", "state" : 1 }
{ "_id" : "shard2", "host" : "shard2/172.19.147.248:27002,172.19.147.249:27002", "state" : 1 }
{ "_id" : "shard3", "host" : "shard3/172.19.147.247:27003,172.19.147.249:27003", "state" : 1 }
active mongoses:
"4.2.7" : 3
autosplit:
Currently enabled: yes
balancer:
Currently enabled: yes
Currently running: no
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
6 : Success
databases:
{ "_id" : "test", "primary" : "shard1", "partitioned" : false, "version" : { "uuid" : UUID("4903b5ec-3f05-401b-8ee3-7449e14e8b67"), "lastMod" : 1 } }
四、开启数据库的分片
mongos> sh.enableSharding("test")
{
"ok" : 1,
"operationTime" : Timestamp(1628818551, 3),
"$clusterTime" : {
"clusterTime" : Timestamp(1628818551, 3),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
}
}
五、新建表的索引
命令db.table.ensureIndex中
{"_id":“hashed”}：哈希(hash)分片，对单列使用hash索引作为分片键
{"_id":1}：范围(range)分片，可以使用多个字段作为分片键，并将数据划分为由分片键确定的连续范围
mongos> db.table.ensureIndex({"_id":1})
{
"raw" : {
"shard1/172.19.147.247:27001,172.19.147.248:27001" : {
"numIndexesBefore" : 1,
"numIndexesAfter" : 1,
"note" : "all indexes already exist",
"ok" : 1
}
},
"ok" : 1,
"operationTime" : Timestamp(1628818639, 1),
"$clusterTime" : {
"clusterTime" : Timestamp(1628818639, 1),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
}
}
六、开启表分片
mongos> sh.shardCollection( "test.table", { "_id" : 1 } )
{
"collectionsharded" : "test.table",
"collectionUUID" : UUID("dc4df1ae-045f-4c94-82b0-557474f1942d"),
"ok" : 1,
"operationTime" : Timestamp(1628819535, 14),
"$clusterTime" : {
"clusterTime" : Timestamp(1628819535, 14),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
}
}
七、插入数据
mongos> for (var i = 0; i < 100000; i++) db.table.insert({_id: Math.random()});
八、再次查看状态
mongos> sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("611239f7d5eb662c357d1f8a")
}
shards:
{ "_id" : "shard1", "host" : "shard1/172.19.147.247:27001,172.19.147.248:27001", "state" : 1 }
{ "_id" : "shard2", "host" : "shard2/172.19.147.248:27002,172.19.147.249:27002", "state" : 1 }
{ "_id" : "shard3", "host" : "shard3/172.19.147.247:27003,172.19.147.249:27003", "state" : 1 }
active mongoses:
"4.2.7" : 3
autosplit:
Currently enabled: yes
balancer:
Currently enabled: yes
Currently running: no
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
8 : Success
databases:
{ "_id" : "test", "primary" : "shard1", "partitioned" : true, "version" : { "uuid" : UUID("4903b5ec-3f05-401b-8ee3-7449e14e8b67"), "lastMod" : 1 } }
test.table
shard key: { "_id" : 1 }
unique: false
balancing: true
chunks:
shard1 2
shard2 1
shard3 1
{ "_id" : { "$minKey" : 1 } } -->> { "_id" : 0.29220988526755465 } on : shard3 Timestamp(2, 0)
{ "_id" : 0.29220988526755465 } -->> { "_id" : 0.5833127748590623 } on : shard2 Timestamp(3, 0)
{ "_id" : 0.5833127748590623 } -->> { "_id" : 0.8756424820024329 } on : shard1 Timestamp(3, 1)
{ "_id" : 0.8756424820024329 } -->> { "_id" : { "$maxKey" : 1 } } on : shard1 Timestamp(1, 3)
九、其他命令
查看分片数据分布
mongos> db.table.getShardDistribution()
Shard shard3 at shard3/172.19.147.247:27003,172.19.147.249:27003
data : 511KiB docs : 29127 chunks : 1
estimated data per chunk : 511KiB
estimated docs per chunk : 29127
Shard shard1 at shard1/172.19.147.247:27001,172.19.147.248:27001
data : 1.71MiB docs : 100000 chunks : 2
estimated data per chunk : 878KiB
estimated docs per chunk : 50000
Shard shard2 at shard2/172.19.147.248:27002,172.19.147.249:27002
data : 512KiB docs : 29128 chunks : 1
estimated data per chunk : 512KiB
estimated docs per chunk : 29128
Totals
data : 2.71MiB docs : 158255 chunks : 4
Shard shard3 contains 18.4% data, 18.4% docs in cluster, avg obj size on shard : 18B
Shard shard1 contains 63.18% data, 63.18% docs in cluster, avg obj size on shard : 18B
Shard shard2 contains 18.4% data, 18.4% docs in cluster, avg obj size on shard : 18B
查看表的状态
mongos> db.trade.stats()
内容较多不再展示
mongos> db.table.stats().sharded
true
查看MongoDB整体分片情况
mongos> use config
switched to db config
mongos> db.shards.find()
{ "_id" : "shard1", "host" : "shard1/172.19.147.247:27001,172.19.147.248:27001", "state" : 1 }
{ "_id" : "shard2", "host" : "shard2/172.19.147.248:27002,172.19.147.249:27002", "state" : 1 }
{ "_id" : "shard3", "host" : "shard3/172.19.147.247:27003,172.19.147.249:27003", "state" : 1 }
mongos>