mongodb分片(sharding)搭建、应用及管理

1.启动shard server
# mkdir -p /data/shard/s0
# mkdir -p /data/shard/s1
# mkdir -p /data/shard/log

# cd /usr/local/mongodb/bin
# ./mongod --shardsvr --port 20000 --dbpath /data/shard/s0 --fork --logpath /data/shard/log/s0.log --directoryperdb
# ./mongod --shardsvr --port 20001 --dbpath /data/shard/s1 --fork --logpath /data/shard/log/s1.log --directoryperdb

2.启动config server
# mkdir -p /data/shard/config
# cd /usr/local/mongodb/bin
# ./mongod --configsvr --port 30000 --dbpath /data/shard/config --fork --logpath /data/shard/log/config.log --directoryperdb

3.启动route process
# /usr/local/mongodb/bin/mongos --prot 40000 --configdb localhost:30000 --fork --logpath /data/shard/log/route.log --chunkSize 1

4.配置sharding
# /usr/local/mongodb/bin/mongo admin --port 40000
> db.runCommand({addshard:"localhost:20000"})
> db.runCommand({addshard:"localhost:20001"})
> db.runCommand({enablesharding:"test"})
> db.runCommand({shardcollection:"test.users",key:{_id:1}})

5.验证sharding
# /usr/local/mongodb/bin/mongo admin --port 40000
> use test
> for(var i=1;i<=500000;i++) db.users.insert({age:i,name:"smith",addr:"newyork",country:"america"})
> db.users.stats()
> exit
# ll /data/shard/s0/test
# ll /data/shard/s1/test

6.维护sharding
1)列出所有shard server
# /usr/local/mongodb/bin/mongo admin --port 40000
> db.runCommand({listshards:1})

2)查看sharding信息
# /usr/local/mongodb/bin/mongo admin --port 40000
> printShardingStatus()

3)查看特定实例是否为shard server
# /usr/local/mongodb/bin/mongo admin --port 20001
> db.runCommand({isdbgrid:1})

4)对现有表进行sharding
# /usr/local/mongodb/bin/mongo admin --port 40000
> use test
> db.users_2.stats()
> use admin
> db.runCommand({shardcollection:"test.users_2",key{_id:1}})
> use test
> db.users_2.stats()

5)新增shard server
# mkdir /data/shard/s2
# /usr/local/mongodb/bin/mongod --shardsvt --port 20002 --dbpath /data/shard/s2 --fork --logpath /data/shard/log/s2.log --directoryperdb
# /usr/local/mongodb/bin/mongo admin --port 40000
> db.runCommand({addshard:"localhost:20002"})
> use test
> db.users_2.stats()

6)移除shard server
# /usr/local/mongodb/bin/mongo admin --port 40000
>use admin
> db.runCommand({removeshard:"localhost:20002"})
--可反复运行该命令，直到shard server服务器移除，期间，state值：started-->ongoing,直到最后errmsg:db assertion failure,表示该shard server移除成功.
> use test
> db.users_2.stats()