搭建mongodb分布式集群(分片集群)
2020-01-02 12:56:37
介绍：
分片（sharding）是指将数据库拆分，将其分散在不同的机器上的过程。将数据分散到不同的机器上，不需要功能强大的服务器就可以存储更多的数据和处理更大的负载。基本思想就是将集合切成小块，这些块分散到若干片里，每个片只负责总数据的一部分，最后通过一个均衡器来对各个分片进行均衡（数据迁移）。通过一个名为mongos的路由进程进行操作，mongos知道数据和片的对应关系（通过配置服务器）。大部分使用场景都是解决磁盘空间的问题，对于写入有可能会变差（+++里面的说明+++），查询则尽量避免跨分片查询。使用分片的时机：
Shard Server: mongod 实例，用于存储实际的数据块，实际生产环境中一个shard server角色可由几台机器组个一个relica set承担，防止主机单点故障;
Config Server: mongod 实例，存储了整个 Cluster Metadata，其中包括 chunk 信息。
Route Server: mongos 实例，前端路由，客户端由此接入，且让整个集群看上去像单一数据库，前端应用可以透明使用
主机规划：
| IP地址 | 实例(端口) | 实例(端口) | 实例(端口) | 实例(端口) | 实例(端口) |
| 192.168.2.3 | mongos(27107) | configsvr(20000) | shard1(27018) | shard2(27019) | shard3(27020) |
| 192.168.2.4 | mongos(27107) | configsvr(20000) | shard1(27018) | shard2(27019) | shard3(27020) |
| 192.168.2.5 | mongos(27107) | configsvr(20000) | shard1(27018) | shard2(27019) | shard3(27020) |
目录创建：
在每台服务器创建对应的目录
1 mkdir -p /data/mongodb/{share1,share2,share3}/db
2 mkdir -p /data/mongodb/mongos/db
3 mkdir -p /data/mongodb/configsvr/db
4 mkdir -p /data/mongodb/{conf,logs}
创建配置文件：
1 touch /data/mongodb/conf/configsvr.conf
2 touch /data/mongodb/conf/mongos.conf
3 touch /data/mongodb/conf/shard1.conf
4 touch /data/mongodb/conf/shard2.conf
5 touch /data/mongodb/conf/shard3.conf
配置文件详情：
configsvr.conf
1 systemLog:
2 destination: file
3 logAppend: true
4 path: /data/mongodb/logs/configsvr.log
5 storage:
6 dbPath: /data/mongodb/configsvr/db 7 journal: 8 enabled: true 9 processManagement: 10 fork: true 11 pidFilePath: /data/mongodb/configsvr/configsvr.pid 12 net: 13 port: 20000 14 bindIp: 0.0.0.0 15 replication: 16 replSetName: config 17 sharding: 18 clusterRole: configsvr
shard1.conf
1 systemLog:
2 destination: file
3 logAppend: true
4 path: /data/mongodb/logs/shard1.log
5 storage:
6 dbPath: /data/mongodb/shard1/db 7 journal: 8 enabled: true 9 processManagement: 10 fork: true 11 pidFilePath: /data/mongodb/shard1/shard1.pid 12 net: 13 port: 27018 14 bindIp: 0.0.0.0 15 replication: 16 replSetName: shard1 17 sharding: 18 clusterRole: shardsvr
shard2.conf
1 systemLog:
2 destination: file
3 logAppend: true
4 path: /data/mongodb/logs/shard2.log
5 storage:
6 dbPath: /data/mongodb/shard2/db 7 journal: 8 enabled: true 9 processManagement: 10 fork: true 11 pidFilePath: /data/mongodb/shard2/shard2.pid 12 net: 13 port: 27019 14 bindIp: 0.0.0.0 15 replication: 16 replSetName: shard2 17 sharding: 18 clusterRole: shardsvr
shard3.conf
1 systemLog:
2 destination: file
3 logAppend: true
4 path: /data/mongodb/logs/shard3.log
5 storage:
6 dbPath: /data/mongodb/shard3/db 7 journal: 8 enabled: true 9 processManagement: 10 fork: true 11 pidFilePath: /data/mongodb/shard3/shard3.pid 12 net: 13 port: 27020 14 bindIp: 0.0.0.0 15 replication: 16 replSetName: shard3 17 sharding: 18 clusterRole: shardsvr
mongos.conf
1 systemLog:
2 destination: file
3 logAppend: true
4 path: /data/mongodb/logs/mongos.log
5 processManagement:
6 fork: true 7 pidFilePath: /data/mongodb/mongos/mongos.pid 8 net: 9 port: 27017 10 bindIp: 0.0.0.0 11 sharding: 12 configDB: config/192.168.2.3:20000,192.168.2.4:20000,192.168.2.5:20000
启动命令：
1 /data/mongodb/bin/mongod -f /data/mongodb/config/configser.conf
2 /data/mongodb/bin/mongod -f /data/mongodb/config/shard1.conf
3 /data/mongodb/bin/mongod -f /data/mongodb/config/shard2.conf
4 /data/mongodb/bin/mongod -f /data/mongodb/config/shard3.conf
5 /data/mongodb/bin/mongod -f /data/mongodb/config/mongos.conf
停止命令:
killall mongod #停止config 和shard
killall mongos #停止 mongos
连接 shard1
/data/mongodb/bin/mongo 192.168.2.3:27018
执行
1 rs.initiate({
2 "_id":"shard1",
3 "members":[
4 {
5 "_id":0,
6 "host":"192.168.2.3:27018"
7 }, 8 { 9 "_id":1, 10 "host":"192.168.2.4:27018" 11 }, 12 { 13 "_id":2, 14 "host":"192.168.2.5:27018" 15 } 16 ] 17 })
连接 shard2
/data/mongodb/bin/mongo 192.168.2.3:27019
执行
1 rs.initiate({
2 "_id":"shard2",
3 "members":[
4 {
5 "_id":0,
6 "host":"192.168.2.3:27019"
7 }, 8 { 9 "_id":1, 10 "host":"192.168.2.4:27019" 11 }, 12 { 13 "_id":2, 14 "host":"192.168.2.5:27019" 15 } 16 ] 17 })
连接 shard3
/data/mongodb/bin/mongo 192.168.2.3:27020
执行
1 rs.initiate({
2 "_id":"shard3",
3 "members":[
4 {
5 "_id":0,
6 "host":"192.168.2.3:27020"
7 }, 8 { 9 "_id":1, 10 "host":"192.168.2.4:27020" 11 }, 12 { 13 "_id":2, 14 "host":"192.168.2.5:27020" 15 } 16 ] 17 })
连接 config
/data/mongodb/bin/mongo 192.168.2.3:20000
1 rs.initiate({
2 "_id":"config",
3 "members":[
4 {
5 "_id":0,
6 "host":"192.168.2.3:20000"
7 }, 8 { 9 "_id":1, 10 "host":"192.168.2.4:20000" 11 }, 12 { 13 "_id":2, 14 "host":"192.168.2.5:20000" 15 } 16 ] 17 })
连接 mongos 添加路由
/data/mongodb/bin/mongo 192.168.2.3:27017
1 sh.addShard("shard1/192.168.2.3:27018,192.168.2.4:27018,192.168.2.5:27018")
2 sh.addShard("shard2/192.168.2.3:27019,192.168.2.4:27019,192.168.2.5:27019")
3 sh.addShard("shard3/192.168.2.3:27020,192.168.2.4:27020,192.168.2.5:27020")
登录 mongos 授权管理员
1 use admin
2 db.createUser({user:'admin',pwd:'admin',roles:['clusterAdmin','dbAdminAnyDatabase','userAdminAnyDatabase','readWriteAnyDatabase']})
授权库账号
use df_test
db.createUser({user:'df_test',pwd:'admin',roles:['readWrite']})