mongodb学习笔记(5)——Sharding Cluster 分片集群及搭建过程


mongodb学习笔记(5)——Sharding Cluster 分片集群及搭建过程
shard
 存储应用数据记录。实际生产环境中一个shard server角色可由几台机器组个一个replica set承担,防止主机单点故障。

Config Server
 存储集群所有节点、分片数据路由信息。默认需要分配3个Config Server,mongod实例,存储了整个 ClusterMetadata,其中包括 chunk信息。

Mongos
 提供对外应用访问,所有操作均通过mongos执行。一般有多个mongos节点。数据迁移和数据自动平衡。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

5.1 规划

10个实例: 38017-38026
(1)configserver
 3台构成的复制集(1主2从,不支持arbiter)38018-38020(复制集名字configsvr)

(2)shard节点;
 shd1: 38021-23 (1主2从,其中一个节点为arbiter,复制集名字为shd1)
 shd2: 38024-26 (1主2从,其中一个节点为arbiter,复制集名字为shd2)

5.2 shard复制集配置:

5.2.1 目录创建:

mkdir -p /mongodb/38021/conf  /mongodb/38021/data  /mongodb/38021/log
mkdir -p /mongodb/38022/conf  /mongodb/38022/data  /mongodb/38022/log
mkdir -p /mongodb/38023/conf  /mongodb/38023/data  /mongodb/38023/log  
mkdir -p /mongodb/38024/conf  /mongodb/38024/data  /mongodb/38024/log
mkdir -p /mongodb/38025/conf  /mongodb/38025/data  /mongodb/38025/log  
mkdir -p /mongodb/38026/conf  /mongodb/38026/data  /mongodb/38026/log

5.2.2 修改配置文件:

shd1:

vi /mongodb/38021/conf/mongodb.conf

根据需求修改相应参数:

systemLog:
    destination: file
    path: "/mongodb/38021/log/mongodb.log"
    logAppend: true
storage:
    dbPath: "/mongodb/38021/data"
    journal:
        enabled: true
    directoryPerDB: true
    #engine: wiredTiger
    wiredTiger:
        engineConfig:
            cacheSizeGB: 1
            directoryForIndexes: true
        collectionConfig:
            blockCompressor: zlib
        indexConfig:
            prefixCompression: true
processManagement:
    fork: true
net:
    bindIp: 192.168.253.129,127.0.0.1
    port: 38021
replication:
    oplogSizeMB: 2048   
    replSetName: shd1
sharding:
    clusterRole: shardsvr
cp /mongodb/38021/conf/mongodb.conf  /mongodb/38022/conf/
cp /mongodb/38021/conf/mongodb.conf  /mongodb/38023/conf/

sed 's#38021#38022#g' /mongodb/38022/conf/mongodb.conf -i
sed 's#38021#38023#g' /mongodb/38023/conf/mongodb.conf -i

shd2:

vi /mongodb/38024/conf/mongodb.conf

根据需求修改相应参数:

systemLog:
   destination: file
   path: "/mongodb/38024/log/mongodb.log"
   logAppend: true
storage:
   dbPath: "/mongodb/38024/data"
   journal:
       enabled: true
   directoryPerDB: true
   #engine: wiredTiger
   wiredTiger:
       engineConfig:
           cacheSizeGB: 1
           directoryForIndexes: true
       collectionConfig:
           blockCompressor: zlib
       indexConfig:
           prefixCompression: true
processManagement:
   fork: true
net:
   bindIp: 192.168.253.129,127.0.0.1
   port: 38024
replication:
   oplogSizeMB: 2048   
   replSetName: shd2
sharding:
   clusterRole: shardsvr
cp /mongodb/38024/conf/mongodb.conf  /mongodb/38025/conf/
cp /mongodb/38024/conf/mongodb.conf  /mongodb/38026/conf/

sed 's#38024#38025#g' /mongodb/38025/conf/mongodb.conf -i
sed 's#38024#38026#g' /mongodb/38026/conf/mongodb.conf -i

5.2.3 启动所有节点,并搭建复制集

mongod -f  /mongodb/38021/conf/mongodb.conf
mongod -f  /mongodb/38022/conf/mongodb.conf
mongod -f  /mongodb/38023/conf/mongodb.conf
mongod -f  /mongodb/38024/conf/mongodb.conf
mongod -f  /mongodb/38025/conf/mongodb.conf
mongod -f  /mongodb/38026/conf/mongodb.conf
mongo  --port 38021

use admin

config ={ _id: 'shd1', members: [
                           {_id: 0, host: '192.168.253.129:38021'},
                           {_id: 1, host: '192.168.253.129:38022'},
                           {_id: 2, host: '192.168.253.129:38023',"arbiterOnly":true}
                           ]
        }
rs.initiate(config)
mongo  --port 38024

use admin

config ={ _id: 'shd2', members: [
                           {_id: 0, host: '192.168.253.129:38024'},
                           {_id: 1, host: '192.168.253.129:38025'},
                           {_id: 2, host: '192.168.253.129:38026',"arbiterOnly":true}
                           ]
        }
rs.initiate(config)

5.3 config 节点配置

5.3.1 目录创建

mkdir -p /mongodb/38018/conf  /mongodb/38018/data  /mongodb/38018/log
mkdir -p /mongodb/38019/conf  /mongodb/38019/data  /mongodb/38019/log  
mkdir -p /mongodb/38020/conf  /mongodb/38020/data  /mongodb/38020/log

5.3.2 修改配置文件

vi /mongodb/38018/conf/mongodb.conf
systemLog:
    destination: file
    path: "/mongodb/38018/log/mongodb.log"
    logAppend: true
storage:
    dbPath: "/mongodb/38018/data"
    journal:
        enabled: true
    directoryPerDB: true
    #engine: wiredTiger
    wiredTiger:
        engineConfig:
            cacheSizeGB: 1
            directoryForIndexes: true
        collectionConfig:
            blockCompressor: zlib
        indexConfig:
            prefixCompression: true
processManagement:
    fork: true
net:
    bindIp: 192.168.253.129,127.0.0.1
    port: 38018
replication:
    oplogSizeMB: 2048   
    replSetName: configReplSet
sharding:
    clusterRole: configsvr
cp /mongodb/38018/conf/mongodb.conf  /mongodb/38019/conf/
cp /mongodb/38018/conf/mongodb.conf  /mongodb/38020/conf/

sed 's#38018#38019#g' /mongodb/38019/conf/mongodb.conf -i
sed 's#38018#38020#g' /mongodb/38020/conf/mongodb.conf -i

5.3.3 启动节点,并配置复制集:

mongod -f  /mongodb/38018/conf/mongodb.conf
mongod -f  /mongodb/38019/conf/mongodb.conf
mongod -f  /mongodb/38020/conf/mongodb.conf
mongo --port 38018

use admin

config ={ _id: 'configReplSet', members: [
                           {_id: 0, host: '192.168.253.129:38018'},
                           {_id: 1, host: '192.168.253.129:38019'},
                           {_id: 2, host: '192.168.253.129:38020'}
                           ]
        }
rs.initiate(config)

 注:configserver可以是一个节点,官方建议复制集。configserver不能有arbiter。
新版本中,要求必须是复制集
 注:mongodb 3.4之后,虽然要求config server为replica set,但是不支持arbiter

==================================================

5.4 mongos节点配置

5.4.1 目录创建

mkdir -p /mongodb/38017/conf    /mongodb/38017/log

5.4.2 修改配置文件

vi /mongodb/38017/conf/mongos.conf
systemLog:
    destination: file
    path: "/mongodb/38017/log/mongodb.log"
    logAppend: true
processManagement:
    fork: true
net:
    bindIp: 192.168.253.129,127.0.0.1
    port: 38017
sharding:
    configDB: configReplSet/192.168.253.129:38018,192.168.253.129:38019,192.168.253.129:38020

5.4.3 启动mongos

mongos -f /mongodb/38017/conf/mongos.conf

5.5 分片集群操作:

连接到其中一个mongos(192.168.253.129),做以下配置:
(1)连接到mongos的admin数据库

su - mongodb
mongo 192.168.253.129:38017/admin

(2)添加分片

db.runCommand( { addshard : "shd1/192.168.253.129:38021,192.168.253.129:38022,192.168.253.129:38023",name:"shard1" } )
db.runCommand( { addshard : "shd2/192.168.253.129:38024,192.168.253.129:38025,192.168.253.129:38026",name:"shard2" } )

(3)列出分片

mongos> db.runCommand( { listshards : 1 } )

(4)整体状态查看

mongos> sh.status()

5.6 balancer操作

介绍:
mongos的一个重要功能,自动巡查所有shard节点上的chunk的情况,自动做chunk迁移。
什么时候工作:
 1、自动运行,会检测系统不繁忙的时候迁移
 2、在做节点删除的时候,立即开始迁移工作
 3、balancer只能在预定的时间窗口内运行

有需要的时可以关闭和开启balancer(备份的时候)

mongos> sh.stopBalancer()
mongos> sh.startBalancer()

5.6.1 自定义 自动平衡进行的时间段

https://docs.mongodb.com/manual/tutorial/manage-sharded-cluster-balancer/#schedule-the-balancing-window
// connect to mongos

use config
sh.setBalancerState( true )
db.settings.update(
  { "_id" : "balancer" },
  { $set : { activeWindow : { start : "3:00",stop : "5:00" }  } },
  true
)

sh.getBalancerWindow()
sh.status()

5.6.2 关于集合的balancer(了解)

关闭某个集合下的balance

sh.disableBalancing("students.grades")

打开某个集合的balancer

sh.enableBalancing("students.grades")

确定某个集合的balance是开启或者关闭

db.getSiblingDB("config").collections.findOne({_id : "students.grades"}).noBalance;