无论Oracle还是mysql数据库都有分区的概念，即同一张表物理上不在同一台机器上，有效缓解了表都集中存在一台机器的压力。当然，mongodb也有类似的机制，即是分片。具体理论知识大家可以参考网上文档，我这里只记录下具体操作步骤dc166a30dd685af75d234808f3f9cdf6.png参考网络上一个图。我选用的是2个副本集+1个仲裁。实际上我这里分片集群需要3个mongos，3个config server，数据分片3个shard server，对应着还有3个副本，3个仲裁节点，总共需要15个实例。因为我资源确实紧张，又不想影响实验效果。冥思苦想了一阵，索性在一台机器上实现得了，分给不同的实例以不同的端口就好了。闲话少说，开始搞起！！！1. 资源划分（感觉这是最纠结的一步）

2. mongdb的安装这个可以参考博主的前一篇章进行安装高可用mongodb集群的学习记录(一安装配置MongoDB)3.创建所需要的目录#创建所需要的目录 [root@DB mongodb]# mkdir -p mongos{1..3}/log [root@DB mongodb]# mkdir -p config{1..3}/log [root@DB mongodb]# mkdir -p config{1..3}/data [root@DB mongodb]# mkdir -p shard{1..3}_{1..3}/log [root@DB mongodb]# mkdir -p shard{1..3}_{1..3}/data

4. 启动每一个配置服务器#启动配置服务器 mongod --configsvr --dbpath config1/data --port 21001 --logpath config1/log/config.log --fork mongod --configsvr --dbpath config2/data --port 21002 --logpath config2/log/config.log --fork mongod --configsvr --dbpath config3/data --port 21003 --logpath config3/log/config.log --fork

5.启动mongos服务器mongos --configdb 192.168.221.160:21001,192.168.221.160:21002,192.168.221.160:21003 --port 20001 --logpath mongos1/log/mongos.log --fork mongos --configdb 192.168.221.160:21001,192.168.221.160:21002,192.168.221.160:21003 --port 20002 --logpath mongos2/log/mongos.log --fork mongos --configdb 192.168.221.160:21001,192.168.221.160:21002,192.168.221.160:21003 --port 20003 --logpath mongos3/log/mongos.log --fork

6.启动分片的副本集 mongod --shardsvr --replSet shard1 --port 21101 --dbpath shard1_1/data --logpath shard1_1/log/shard.log --fork --nojournal --oplogSize 10    mongod --shardsvr --replSet shard1 --port 21201 --dbpath shard1_2/data --logpath shard1_2/log/shard.log --fork --nojournal --oplogSize 10    mongod --shardsvr --replSet shard1 --port 21301 --dbpath shard1_3/data --logpath shard1_3/log/shard.log --fork --nojournal --oplogSize 10    mongod --shardsvr --replSet shard2 --port 21102 --dbpath shard2_1/data --logpath shard2_1/log/shard.log --fork --nojournal --oplogSize 10    mongod --shardsvr --replSet shard2 --port 21202 --dbpath shard2_2/data --logpath shard2_2/log/shard.log --fork --nojournal --oplogSize 10    mongod --shardsvr --replSet shard2 --port 21302 --dbpath shard2_3/data --logpath shard2_3/log/shard.log --fork --nojournal --oplogSize 10    mongod --shardsvr --replSet shard3 --port 21103 --dbpath shard3_1/data --logpath shard3_1/log/shard.log --fork --nojournal --oplogSize 10    mongod --shardsvr --replSet shard3 --port 21203 --dbpath shard3_2/data --logpath shard3_2/log/shard.log --fork --nojournal --oplogSize 10    mongod --shardsvr --replSet shard3 --port 21303 --dbpath shard3_3/data --logpath shard3_3/log/shard.log --fork --nojournal --oplogSize 10

7.分别对每个分片配置副本集,任意登录一个节点#设置第一个分片副本集 [root@DB ~]# mongo 192.168.221.160:21101 MongoDB shell version: 3.0.6 connecting to: 192.168.221.160:21101/test> use admin switched to db admin #定义副本集配置信息 > config = {_id:"shard1",members:[{_id:0,host:"192.168.221.160:21101"},{_id:1,host:"192.168.221.160:21201"},{_id:2,host:"192.168.221.160:21301",arbiterOnly:true}]} { "_id" : "shard1", "members" : [ { "_id" : 0, "host" : "192.168.221.160:21101"}, { "_id" : 1, "host" : "192.168.221.160:21201"}, { "_id" : 2, "host" : "192.168.221.160:21301", "arbiterOnly" : true} ] } #初始化副本集信息 > rs.initiate(config) { "ok" : 1 } shard1:OTHER>    #设置第二个分片副本集 [root@DB ~]# mongo 192.168.221.160:21102 MongoDB shell version: 3.0.6 connecting to: 192.168.221.160:21102/test> use admin switched to db admin > config = {_id:"shard2",members:[{_id:0,host:"192.168.221.160:21102"},{_id:1,host:"192.168.221.160:21202"},{_id:2,host:"192.168.221.160:21302",arbiterOnly:true}]} { "_id" : "shard2", "members" : [ { "_id" : 0, "host" : "192.168.221.160:21102"}, { "_id" : 1, "host" : "192.168.221.160:21202"}, { "_id" : 2, "host" : "192.168.221.160:21302", "arbiterOnly" : true} ] } > rs.initiate(config) { "ok" : 1 } shard2:OTHER>  #设置第三个分片副本集 [root@DB ~]# mongo 192.168.221.160:21103 MongoDB shell version: 3.0.6 connecting to: 192.168.221.160:21103/test> use admin switched to db admin > config = {_id:"shard3",members:[{_id:0,host:"192.168.221.160:21103"},{_id:1,host:"192.168.221.160:21203"},{_id:2,host:"192.168.221.160:21303",arbiterOnly:true}]} { "_id" : "shard3", "members" : [ { "_id" : 0, "host" : "192.168.221.160:21103"}, { "_id" : 1, "host" : "192.168.221.160:21203"}, { "_id" : 2, "host" : "192.168.221.160:21303", "arbiterOnly" : true} ] } > rs.initiate(config) { "ok" : 1 } shard3:OTHER>

8.登录到每一个mongos，设置分片配置，让分片生效#串联路由服务器与分片副本集1 [root@DB ~]# mongo 192.168.221.160:20001 MongoDB shell version: 3.0.6 connecting to: 192.168.221.160:20001/testServer has startup warnings:  2017-11-15T13:51:20.732+0800 I CONTROL  ** WARNING: You are running this process as the root user, which is not recommended. 2017-11-15T13:51:20.733+0800 I CONTROL  mongos> use admin switched to db admin mongos> db.runCommand({addshard:"shard1/192.168.221.160:21101,192.168.221.160:21201,192.168.221.160:21301"}) { "shardAdded" : "shard1", "ok" : 1 } mongos>  #串联路由服务器与分片副本集2 [root@DB ~]# mongo 192.168.221.160:20002 MongoDB shell version: 3.0.6 connecting to: 192.168.221.160:20002/testServer has startup warnings:  2017-11-15T13:51:43.660+0800 I CONTROL  ** WARNING: You are running this process as the root user, which is not recommended. 2017-11-15T13:51:43.661+0800 I CONTROL  mongos> use admin switched to db admin mongos> db.runCommand({addshard:"shard2/192.168.221.160:21102,192.168.221.160:21202,192.168.221.160:21302"}) { "shardAdded" : "shard2", "ok" : 1 } mongos>    #串联路由服务器与分片副本集3 [root@DB ~]# mongo 192.168.221.160:20003 MongoDB shell version: 3.0.6 connecting to: 192.168.221.160:20003/testServer has startup warnings:  2017-11-15T13:51:59.589+0800 I CONTROL  ** WARNING: You are running this process as the root user, which is not recommended. 2017-11-15T13:51:59.589+0800 I CONTROL  mongos> use admin switched to db admin mongos> db.runCommand({addshard:"shard3/192.168.221.160:21103,192.168.221.160:21203,192.168.221.160:21303"}) { "shardAdded" : "shard3", "ok" : 1 } mongos>

9.查看分片服务器的配置信息：mongos> db.runCommand({listshards:1}) { "shards" : [ { "_id" : "shard1", "host" : "shard1/192.168.221.160:21101,192.168.221.160:21201"}, { "_id" : "shard2", "host" : "shard2/192.168.221.160:21102,192.168.221.160:21202"}, { "_id" : "shard3", "host" : "shard3/192.168.221.160:21103,192.168.221.160:21203"} ], "ok" : 1 } mongos>

    仲裁节点不储存数据，没有在这里显示出来10.连接mongos上，指定数据库、指定集合让分片生效[root@DB ~]# mongo 192.168.221.160:20001 MongoDB shell version: 3.0.6 connecting to: 192.168.221.160:20001/testmongos> db.runCommand({enablesharding:"testdb"}) { "ok" : 0, "errmsg" : "enableSharding may only be run against the admin database.", "code" : 13 } mongos> use admin switched to db admin mongos> db.runCommand({enablesharding:"testdb"}) { "ok" : 1 } mongos> db.runCommand({shardcollection:"testdb.table1",key:{id:1}}) { "collectionsharded" : "testdb.table1", "ok" : 1 } mongos>

设置testdb的 table1 表需要分片，根据 id 自动分片到 shard1 ，shard2，shard3 上面去。要这样设置是因为不是所有mongodb 的数据库和表都需要分片 11.测试分片片配置效果[root@DB ~]# mongo 192.168.221.160:20001 MongoDB shell version: 3.0.6 connecting to: 192.168.221.160:20001/testServer has startup warnings:  2017-11-15T13:51:20.732+0800 I CONTROL  ** WARNING: You are running this process as the root user, which is not recommended. 2017-11-15T13:51:20.733+0800 I CONTROL  mongos> use testdb; switched to db testdb mongos> for (var i = 1;i db.table1.stats() { "sharded" : true, "paddingFactorNote" : "paddingFactor is unused and unmaintained in 3.0. It remains hard coded to 1.0 for compatibility only.", "userFlags" : 1, "capped" : false, "ns" : "testdb.table1", "count" : 10000, "numExtents" : 7, "size" : 1120000, "storageSize" : 2809856, "totalIndexSize" : 654080, "indexSizes" : { "_id_" : 351568, "id_1" : 302512 }, "avgObjSize" : 112, "nindexes" : 2, "nchunks" : 3, "shards" : { "shard1" : { "ns" : "testdb.table1", "count" : 9991, "size" : 1118992, ... "ok" : 1, "$gleStats" : { "lastOpTime" : Timestamp(0, 0), "electionId" : ObjectId("5a0bd9cf86a6b76e11b5d820") } }, "shard2" : { "ns" : "testdb.table1", "count" : 1, "size" : 112, ... "ok" : 1, "$gleStats" : { "lastOpTime" : Timestamp(0, 0), "electionId" : ObjectId("5a0bdadd74c5945a33a4ae46") } }, "shard3" : { "ns" : "testdb.table1", "count" : 8, "size" : 896, ... "ok" : 1, "$gleStats" : { "lastOpTime" : Timestamp(0, 0), "electionId" : ObjectId("5a0bdb6f1c75115f41ff92f9") } } }, "ok" : 1 } mongos>

可以看到testdb.table1数据已经被分到三个分片，各自分片数量为 shard1 “count” : 9991，shard2 “count” : 1，shard3 “count” : 8。我也不知道为啥分配的不均匀。纳闷ing好了，实验到此结束，关于mongodb的学习会继续进行...

更多MongoDB相关教程见以下内容：

MongoDB文档、集合、数据库简介  http://www.linuxidc.com/Linux/2016-12/138529.htm

MongoDB 3分片部署及故障模拟验证  http://www.linuxidc.com/Linux/2016-12/138529.htm

Linux CentOS 6.5 yum安装MongoDB  http://www.linuxidc.com/Linux/2016-12/137790.htm

CentOS 7 yum方式快速安装MongoDB  http://www.linuxidc.com/Linux/2016-11/137679.htm

MongoDB的查询操作  http://www.linuxidc.com/Linux/2016-10/136581.htm

在 Azure 虚拟机上快速搭建 MongoDB 集群  http://www.linuxidc.com/Linux/2017-09/146778.htm

MongoDB复制集原理  http://www.linuxidc.com/Linux/2017-09/146670.htm

MongoDB 3.4 远程连接认证失败  http://www.linuxidc.com/Linux/2017-06/145070.htm

Ubuntu 16.04中安装MongoDB3.4数据库系统  http://www.linuxidc.com/Linux/2017-07/145526.htm

MongoDB权威指南第2版PDF完整带书签目录 下载见 http://www.linuxidc.com/Linux/2016-12/138253.htm

MongoDB 的详细介绍：请点这里MongoDB 的下载地址：请点这里

本文永久更新链接地址：http://www.linuxidc.com/Linux/2017-11/148740.htm