尝试使用MongoDB进行分片
准备
在EC2上使用四台服务器进行测试。
MongoDB的版本是3.2.9。
服务器配置为core1、db1、db2和db3。
在core1上启动配置服务器和mongos服务器。
wget http://downloads.mongodb.org/linux/mongodb-linux-x86_64-rhel62-3.2.9.tgz
对于conf的配置和mongod的启动（db1，db2，db3）进行设置。
[root@db1 mongodb]# cat conf/shard.conf
port = 27011
dbpath = /root/mongodb/data/shard
fork = true
shardsvr = true
logpath = /root/mongodb/logs/mongo.log
logappend = yes
smallfiles = true
storageEngine = wiredTiger
启动
[root@db2 mongodb]# ./bin/mongod -f conf/shard.conf
在核心1上启动config服务器和mongos。
配置服务器是用于存储分片集群元数据的服务器。
路由服务器作为分片集群的mongod路由器。不存储实际数据。
配置服务器启动
[root@core1 mongodb]# cat conf/config.conf
port = 27001
dbpath = /root/mongodb/data/configdb
fork = true
configsvr = true
logpath = /root/mongodb/logs/mongolog.log
logappend = yes
smallfiles = true
[root@core1 mongodb]# ./bin/mongod -f conf/config.conf
启动mongos服务器时，请不要忘记端口的acl设置。
[root@core1 mongodb]# cat conf/mongos.conf
port = 27000
configdb = core1:27001
chunkSize = 1
fork = true
logpath = /root/mongodb/logs/shard.log
logappend = yes
[root@core1 mongodb]# ./bin/mongos -f conf/mongos.conf
[root@core1 mongodb]# pgrep -lf mongo
3190 ./bin/mongod -f conf/config.conf
3212 ./bin/mongos -f conf/mongos.conf
将Sharding配置在mongos服务器上。
将其添加到集群中
[root@core1 mongodb]# ./bin/mongo --port 27000
MongoDB shell version: 3.2.9
connecting to: 127.0.0.1:27000/test
mongos> sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("588dc5bf70cae5b0591f0d45")
}
shards:
active mongoses:
"3.2.9" : 1
balancer:
Currently enabled: yes
Currently running: no
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
No recent migrations
databases:
mongos> sh.addShard("db1:27011")
{ "shardAdded" : "shard0000", "ok" : 1 }
mongos> sh.addShard("db2:27011")
{ "shardAdded" : "shard0001", "ok" : 1 }
mongos> sh.addShard("db3:27011")
{ "shardAdded" : "shard0002", "ok" : 1 }
mongos> sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("588dc5bf70cae5b0591f0d45")
}
shards:
{ "_id" : "shard0000", "host" : "db1:27011" }
{ "_id" : "shard0001", "host" : "db2:27011" }
{ "_id" : "shard0002", "host" : "db3:27011" }
active mongoses:
"3.2.9" : 1
balancer:
Currently enabled: yes
Currently running: no
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
No recent migrations
databases:
数据输入
通过mongos向数据库插入数据
mongos> use logdb
switched to db logdb
mongos> for(var i=1; i<=100000; i++)db.logs.insert({"uid":i, "value":Math.floor(Math.random()*100000+1)})
WriteResult({ "nInserted" : 1 })
mongos> db.logs.count()
100000
设定索引并执行分片
mongos> db.logs.ensureIndex({uid:1});
{
"raw" : {
"db1:27011" : {
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 1,
"numIndexesAfter" : 2,
"ok" : 1
}
},
"ok" : 1
}
当计算 “chunk” 的数量时，可以看出尚未执行分片技术。
mongos> use config
switched to db config
mongos> show collections
changelog
chunks
databases
lockpings
locks
mongos
settings
shards
tags
version
mongos> db.chunks.count()
0
执行分片并确认
[root@core1 mongodb]# ./bin/mongo --port 27000
MongoDB shell version: 3.2.9
connecting to: 127.0.0.1:27000/test
mongos> sh.enableSharding("logdb")
{ "ok" : 1 }
mongos> sh.shardCollection("logdb.logs", {uid:1})
{ "collectionsharded" : "logdb.logs", "ok" : 1 }
mongos> sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("588dc5bf70cae5b0591f0d45")
}
shards:
{ "_id" : "shard0000", "host" : "db1:27011" }
{ "_id" : "shard0001", "host" : "db2:27011" }
{ "_id" : "shard0002", "host" : "db3:27011" }
active mongoses:
"3.2.9" : 1
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" : "logdb", "primary" : "shard0000", "partitioned" : true }
logdb.logs
shard key: { "uid" : 1 }
unique: false
balancing: true
chunks:
shard0000 4
shard0001 3
shard0002 3
{ "uid" : { "$minKey" : 1 } } -->> { "uid" : 10486 } on : shard0001 Timestamp(2, 0)
{ "uid" : 10486 } -->> { "uid" : 20972 } on : shard0002 Timestamp(3, 0)
{ "uid" : 20972 } -->> { "uid" : 31458 } on : shard0001 Timestamp(4, 0)
{ "uid" : 31458 } -->> { "uid" : 41944 } on : shard0002 Timestamp(5, 0)
{ "uid" : 41944 } -->> { "uid" : 52430 } on : shard0001 Timestamp(6, 0)
{ "uid" : 52430 } -->> { "uid" : 62916 } on : shard0002 Timestamp(7, 0)
{ "uid" : 62916 } -->> { "uid" : 73402 } on : shard0000 Timestamp(7, 1)
{ "uid" : 73402 } -->> { "uid" : 83888 } on : shard0000 Timestamp(1, 7)
{ "uid" : 83888 } -->> { "uid" : 94374 } on : shard0000 Timestamp(1, 8)
{ "uid" : 94374 } -->> { "uid" : { "$maxKey" : 1 } } on : shard0000 Timestamp(1, 9)
mongos> use config
switched to db config
mongos> db.chunks.count()
10
进一步加入
mongos> db.logs.insert({"uid": 100001, "value":100001})
WriteResult({ "nInserted" : 1 })
mongos> for (var i=200000; i<250000; i++)db.logs.insert({"uid": i, "value":100001})
WriteResult({ "nInserted" : 1 })
mongos> db.logs.count()
150001
mongos> sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("588dc5bf70cae5b0591f0d45")
}
shards:
{ "_id" : "shard0000", "host" : "db1:27011" }
{ "_id" : "shard0001", "host" : "db2:27011" }
{ "_id" : "shard0002", "host" : "db3:27011" }
active mongoses:
"3.2.9" : 1
balancer:
Currently enabled: yes
Currently running: no
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
9 : Success
databases:
{ "_id" : "logdb", "primary" : "shard0000", "partitioned" : true }
logdb.logs
shard key: { "uid" : 1 }
unique: false
balancing: true
chunks:
shard0000 5
shard0001 5
shard0002 4
{ "uid" : { "$minKey" : 1 } } -->> { "uid" : 10486 } on : shard0001 Timestamp(10, 1)
{ "uid" : 10486 } -->> { "uid" : 20972 } on : shard0002 Timestamp(3, 0)
{ "uid" : 20972 } -->> { "uid" : 31458 } on : shard0001 Timestamp(4, 0)
{ "uid" : 31458 } -->> { "uid" : 41944 } on : shard0002 Timestamp(5, 0)
{ "uid" : 41944 } -->> { "uid" : 52430 } on : shard0001 Timestamp(6, 0)
{ "uid" : 52430 } -->> { "uid" : 62916 } on : shard0002 Timestamp(7, 0)
{ "uid" : 62916 } -->> { "uid" : 73402 } on : shard0002 Timestamp(9, 0)
{ "uid" : 73402 } -->> { "uid" : 83888 } on : shard0000 Timestamp(9, 1)
{ "uid" : 83888 } -->> { "uid" : 94374 } on : shard0000 Timestamp(1, 8)
{ "uid" : 94374 } -->> { "uid" : 204857 } on : shard0000 Timestamp(7, 2)
{ "uid" : 204857 } -->> { "uid" : 218713 } on : shard0000 Timestamp(7, 3)
{ "uid" : 218713 } -->> { "uid" : 229198 } on : shard0001 Timestamp(9, 2)
{ "uid" : 229198 } -->> { "uid" : 241131 } on : shard0001 Timestamp(9, 3)
{ "uid" : 241131 } -->> { "uid" : { "$maxKey" : 1 } } on : shard0000 Timestamp(10, 0)
由于设置已经完成，所以现在正在执行分片。
通过pymongo进行访问
向本地主机发送请求到mongos
from pymongo import MongoClient
from time import sleep
#c = MongoClient(host=['db1:27011', 'db2:27011', 'db3:27011'], replicaset='rs01')
#print(c.mydb.logs.count())
#print(c.nodes)
c = MongoClient(host="core1:27000")
print(c.logdb.logs.count())
结果如下
$ python -V
Python 3.5.1
$ pip list | grep pymongo
pymongo (3.4.0)
$ python req.py
150001
关闭db1中的mongod并进行确认试试看。
[root@db1 mongodb]# pgrep -lf mongo
2717 ./bin/mongod -f conf/shard.conf
[root@db1 mongodb]# pkill -f mongo
使用mongo客户端连接到mongos并进行确认。
[root@core1 mongodb]# ./bin/mongo --port 27000
MongoDB shell version: 3.2.9
connecting to: 127.0.0.1:27000/test
mongos> use logdb
switched to db logdb
mongos> show collections
2017-01-29T11:16:55.488+0000 E QUERY [thread1] Error: listCollections failed: {
"code" : 13328,
"ok" : 0,
"errmsg" : "connection pool: connect failed db1:27011 : couldn't connect to server db1:27011, connection attempt failed"
} :
_getErrorWithCode@src/mongo/shell/utils.js:25:13
DB.prototype._getCollectionInfosCommand@src/mongo/shell/db.js:773:1
DB.prototype.getCollectionInfos@src/mongo/shell/db.js:785:19
DB.prototype.getCollectionNames@src/mongo/shell/db.js:796:16
shellHelper.show@src/mongo/shell/utils.js:754:9
shellHelper@src/mongo/shell/utils.js:651:15
@(shellhelp2):1:1
从本地主机使用Python访问
$ python req.py
Traceback (most recent call last):
File "req.py", line 8, in <module>
print(c.logdb.logs.count())
File "/home/kw/.pyenv/versions/3.5.1/lib/python3.5/site-packages/pymongo/collection.py", line 1354, in count
return self._count(cmd, collation)
File "/home/kw/.pyenv/versions/3.5.1/lib/python3.5/site-packages/pymongo/collection.py", line 1310, in _count
collation=collation)
File "/home/kw/.pyenv/versions/3.5.1/lib/python3.5/site-packages/pymongo/collection.py", line 232, in _command
collation=collation)
File "/home/kw/.pyenv/versions/3.5.1/lib/python3.5/site-packages/pymongo/pool.py", line 419, in command
collation=collation)
File "/home/kw/.pyenv/versions/3.5.1/lib/python3.5/site-packages/pymongo/network.py", line 116, in command
parse_write_concern_error=parse_write_concern_error)
File "/home/kw/.pyenv/versions/3.5.1/lib/python3.5/site-packages/pymongo/helpers.py", line 210, in _check_command_response
raise OperationFailure(msg % errmsg, code, response)
pymongo.errors.OperationFailure: socket exception [CONNECT_ERROR] for db1:27011
