MongoDB实战系列之六：mongodb的高可用集群设计实战

jopen 12年前

环境：
CentOS 6.0 x64

md01: 10.0.0.11
md02: 10.0.0.12
md03: 10.0.0.14
md04: 10.0.0.15
md05: 10.0.0.16
md06: 10.0.0.17

设计思路：

md01、md02、md03 做一组复制集
md04、md05、md06 做一组复制集
再把这两组复制集用分片做成 shard1、shard2 用LVS 调用

下载安装mongodb

cd /root /tools
wget http: //fastdl.mongodb.org /linux /mongodb-linux-x86_64-2.0.0.tgz
tar zxvf mongodb-linux-x86_64-2.0.0.tgz
mv mongodb-linux-x86_64-2.0.0 /elain /apps /mongodb-linux-x86_64-2.0.0
ln -s /elain /apps /mongodb-linux-x86_64-2.0.0 /elain /apps /mongodb
ln -s /elain /apps /mongodb /bin /* /bin /

#添加用户组

/usr /sbin /groupadd -g 690 mongodb
/usr /sbin /useradd -g mongodb mongodb -u 690 -s /sbin /nologin

各节点hosts文件添加：

true > /etc /hosts
echo -ne "
10.0.0.11 md01
10.0.0.12 md02
10.0.0.14 md03
10.0.0.15 md04
10.0.0.16 md05
10.0.0.17 md06
" >>/etc /hosts

———————————————
副本集配置：
启动各节点：

md01
mkdir -p /elain /logs /mongodb /
mkdir -p /elain /data /mongodb /db
/elain /apps /mongodb /bin /mongod --rest --replSet elain /md01: 27017 --fork --port 27017 --dbpath /elain /data /mongodb /db / --logpath /elain /logs /mongodb /mongodb.log
md02
mkdir -p /elain /logs /mongodb /
mkdir -p /elain /data /mongodb /db
/elain /apps /mongodb /bin /mongod --rest --replSet elain /md02: 27017 --fork --port 27017 --dbpath /elain /data /mongodb /db / --logpath /elain /logs /mongodb /mongodb.log
md03
mkdir -p /elain /logs /mongodb /
mkdir -p /elain /data /mongodb /db
/elain /apps /mongodb /bin /mongod --rest --replSet elain /md03: 27017 --fork --port 27017 --dbpath /elain /data /mongodb /db / --logpath /elain /logs /mongodb /mongodb.log

#启动仲裁节点
在md02上

mkdir /elain /data /mongodb /arb
/elain /apps /mongodb /bin /mongod --fork --rest --replSet elain --dbpath /elain /data /mongodb /arb --port 27015 --logpath /elain /logs /mongodb /mongodb.log

初始化节点:
md01:(登录其中任何一个节点操作皆可)

> rs.initiate ( {
_id : "elain",
members : [
{_id : 1, host : "md01:27017" },
{_id : 2, host : "md02:27017" },
{_id : 3, host : "md03:27017" },
{_id : 4, host : "md02:27015", "arbiterOnly": true },
]
} );

#验证

PRIMARY > rs.status ( )

也可浏览：http://10.0.0.11:28017/_replSet 查看状态

查看副本集状态

>rs.status ( )
>user local;
>rs.isMaster ( )
>db.system.replset.find ( )

查看当前主库：

>db. $cmd.findOne ( {ismaster: 1 } );

另一组副本集同理操作即可;这里为省篇幅就不再写出,但切记两复制集名称不可以重复

—————————————————

启动并配置三台Config Server

#md01,03,05上执行

mkdir -p /elain /data /mongodb /config /
/elain /apps /mongodb /bin /mongod --configsvr --dbpath /elain /data /mongodb /config / --port 20000 --logpath /elain /logs /mongodb /config.log --logappend --fork

5、部署并配置三台Routing Server

指定所有的config sever地址参数，chunkSize是分割数据时每块(Chunk)的单位大小

#md02,md04,md06
/elain /apps /mongodb /bin /mongos --configdbmd01: 20000,md03: 20000,md05: 20000 --port 30000 --chunkSize 100 --logpath /elain /logs /mongodb /mongos.log --logappend --fork

6、命令行添加分片

连接到mongs服务器，并切换到admin

/elain /apps /mongodb /bin /mongo 10.0.0.11: 30000 /admin

db.runCommand ( {
addshard : "elain/md01:27017",
name: "shard1",
maxsize: 2048,
allowLocal:true } );

db.runCommand ( {
addshard : "chujq/md04:27017",
name: "shard2",
maxsize: 2048,
allowLocal:true } );

注：添加复制集elain，其中包含一个服务器md01:27017(还饿别的服务器，如md02、md03)，如果md01挂了，mongos会知道它所连接的是一个复制集，并会使用新的主节点（md02或md03）

db.runCommand ( { listshards : 1 } );

如果列出(sharding)了以上二个你加的shards，表示shards已经配置成功

导入数据：

mongoimport -d elain -c elain --type csv --headerline --file /root /bak /test.csv --host md02: 30000

注：数据自备，我这里是从生产环境下MYSQL里导出的一些真实数据来做测试

#激活数据库分片

db.runCommand ( { enablesharding : "elain" } );
mongos > db.runCommand ( { enablesharding : "elain" } );
{ "ok" : 1 }

mongos > show dbs
config 0.1875GB
elain 0.453125GB
test (empty )

#进入数据库，建立索引，为分片做准备

/elain /apps /mongodb /bin /mongo 10.0.0.12: 30000 /admin

use elain;
db.elain.ensureIndex ( { "client_userid": 1 } );

查看索引：

mongos > db.elain.find ( { "client_userid" : 151512 } ).explain ( );
{
"cursor" : "BtreeCursor client_userid_1",
"nscanned" : 3,
"nscannedObjects" : 3,
"n" : 3,
"millis" : 0,
"nYields" : 0,
"nChunkSkips" : 0,
"isMultiKey" : false,
"indexOnly" : false,
"indexBounds" : {
"client_userid" : [
[
151512,
151512
]
]
}
}

#添加分片：

use admin;
db.runCommand ( { shardcollection : "elain.elain",key : {client_userid: 1 } } )

mongos > db.runCommand ( { shardcollection : "elain.elain",key : {client_userid: 1 } } )
{ "collectionsharded" : "elain.elain", "ok" : 1 }

#查看分片状态

use elain;
db.elain.stats ( );

mongos > db.elain.stats ( );
{
"sharded" : true,
"flags" : 1,
"ns" : "elain.elain",
"count" : 507372,
"numExtents" : 10,
"size" : 84375328,
"storageSize" : 97849344,
"totalIndexSize" : 29253728,
"indexSizes" : {
"_id_" : 16474640,
"client_userid_1" : 12779088
},
"avgObjSize" : 166.29874727024747,
"nindexes" : 2,
"nchunks" : 1,
"shards" : {
"shard2" : {
"ns" : "elain.elain",
"count" : 507372,
"size" : 84375328,
"avgObjSize" : 166.29874727024747,
"storageSize" : 97849344,
"numExtents" : 10,
"nindexes" : 2,
"lastExtentSize" : 26099712,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 29253728,
"indexSizes" : {
"_id_" : 16474640,
"client_userid_1" : 12779088
},
"ok" : 1
}
},
"ok" : 1
}

在分片后新写数据第一次：

mongos > db.elain.stats ( );
{
"sharded" : true,
"flags" : 1,
"ns" : "elain.elain",
"count" : 676496,
"numExtents" : 12,
"size" : 112500436,
"storageSize" : 129179648,
"totalIndexSize" : 47551616,
"indexSizes" : {
"_id_" : 21968912,
"client_userid_1" : 25582704
},
"avgObjSize" : 166.29874529930703,
"nindexes" : 2,
"nchunks" : 8,
"shards" : {
"shard1" : {
"ns" : "elain.elain",
"count" : 0,
"size" : 0,
"storageSize" : 8192,
"numExtents" : 1,
"nindexes" : 2,
"lastExtentSize" : 8192,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 16352,
"indexSizes" : {
"_id_" : 8176,
"client_userid_1" : 8176
},
"ok" : 1
},
"shard2" : {
"ns" : "elain.elain",
"count" : 676496,
"size" : 112500436,
"avgObjSize" : 166.29874529930703,
"storageSize" : 129171456,
"numExtents" : 11,
"nindexes" : 2,
"lastExtentSize" : 31322112,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 47535264,
"indexSizes" : {
"_id_" : 21960736,
"client_userid_1" : 25574528
},
"ok" : 1
}
},
"ok" : 1
}

分片后新写数据第二次：

mongos > db.elain.stats ( );
{
"sharded" : true,
"flags" : 1,
"ns" : "elain.elain",
"count" : 1189194,
"numExtents" : 23,
"size" : 194533928,
"storageSize" : 252874752,
"totalIndexSize" : 87262448,
"indexSizes" : {
"_id_" : 43692544,
"client_userid_1" : 43569904
},
"avgObjSize" : 163.58468677103988,
"nindexes" : 2,
"nchunks" : 8,
"shards" : {
"shard1" : {
"ns" : "elain.elain",
"count" : 396370,
"size" : 62195348,
"avgObjSize" : 156.91234957236924,
"storageSize" : 86114304,
"numExtents" : 11,
"nindexes" : 2,
"lastExtentSize" : 20881408,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 35949872,
"indexSizes" : {
"_id_" : 17954496,
"client_userid_1" : 17995376
},
"ok" : 1
},
"shard2" : {
"ns" : "elain.elain",
"count" : 792824,
"size" : 132338580,
"avgObjSize" : 166.9205019020615,
"storageSize" : 166760448,
"numExtents" : 12,
"nindexes" : 2,
"lastExtentSize" : 37588992,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 51312576,
"indexSizes" : {
"_id_" : 25738048,
"client_userid_1" : 25574528
},
"ok" : 1
}
},
"ok" : 1
}

分片后新写数据第三次：

mongos > db.elain.stats ( );
{
"sharded" : true,
"flags" : 1,
"ns" : "elain.elain",
"count" : 1376876,
"numExtents" : 23,
"size" : 225576604,
"storageSize" : 252874752,
"totalIndexSize" : 100826432,
"indexSizes" : {
"_id_" : 50249696,
"client_userid_1" : 50576736
},
"avgObjSize" : 163.83218532387812,
"nindexes" : 2,
"nchunks" : 10,
"shards" : {
"shard1" : {
"ns" : "elain.elain",
"count" : 494202,
"size" : 77551984,
"avgObjSize" : 156.92365469990003,
"storageSize" : 86114304,
"numExtents" : 11,
"nindexes" : 2,
"lastExtentSize" : 20881408,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 42057344,
"indexSizes" : {
"_id_" : 21600992,
"client_userid_1" : 20456352
},
"ok" : 1
},
"shard2" : {
"ns" : "elain.elain",
"count" : 882674,
"size" : 148024620,
"avgObjSize" : 167.70021548159343,
"storageSize" : 166760448,
"numExtents" : 12,
"nindexes" : 2,
"lastExtentSize" : 37588992,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 58769088,
"indexSizes" : {
"_id_" : 28648704,
"client_userid_1" : 30120384
},
"ok" : 1
}
},
"ok" : 1
}

分片后新写数据第四次（DOWN 掉md04的mongo服务）

mongos > db.elain.stats ( );
{
"sharded" : true,
"flags" : 1,
"ns" : "elain.elain",
"count" : 1686310,
"numExtents" : 26,
"size" : 275761376,
"storageSize" : 353116160,
"totalIndexSize" : 129033632,
"indexSizes" : {
"_id_" : 63265888,
"client_userid_1" : 65767744
},
"avgObjSize" : 163.52946729842083,
"nindexes" : 2,
"nchunks" : 10,
"shards" : {
"shard1" : {
"ns" : "elain.elain",
"count" : 740264,
"size" : 116213588,
"avgObjSize" : 156.98938216636228,
"storageSize" : 141246464,
"numExtents" : 13,
"nindexes" : 2,
"lastExtentSize" : 30072832,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 61810560,
"indexSizes" : {
"_id_" : 32556832,
"client_userid_1" : 29253728
},
"ok" : 1
},
"shard2" : {
"ns" : "elain.elain",
"count" : 946046,
"size" : 159547788,
"avgObjSize" : 168.64696642657967,
"storageSize" : 211869696,
"numExtents" : 13,
"nindexes" : 2,
"lastExtentSize" : 45109248,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 67223072,
"indexSizes" : {
"_id_" : 30709056,
"client_userid_1" : 36514016
},
"ok" : 1
}
},
"ok" : 1
}

总结：通过以上四次的写数据测试，我们可以看到分片是成功的，每次写数据,shard1、shard2都有数据写入，且，在下面的复制集中DOWN 掉任意一台，不影响整个架构的正常服务。

删除片操作

mongos > db.runCommand ( { "removeshard" : "10.0.0.11:27011" } );
{
"msg" : "draining started successfully",
"state" : "started",
"shard" : "shard2",
"ok" : 1
}

再执行，可看到removeshard的挪动进度

mongos > db.runCommand ( { "removeshard" : "10.0.0.11:27011" } );
{
"msg" : "draining ongoing",
"state" : "ongoing",
"remaining" : {
"chunks" : NumberLong ( 3 ),
"dbs" : NumberLong ( 0 )
},
"ok" : 1
}

到此结束

MongoDB实战系列之六：mongodb的高可用集群设计实战

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