MongoDB分片群集的部署（用心描述，详细易懂）！！

概念：

MongoDB分片是使用多个服务器存储数据的方法，以支持巨大的数据存储和对数据进行存储

优势：

1、减少了每个分片需啊哟处理的请求数，群集可以提高自己的存储容量和吞吐量

2、减少了每个分片存储的数据

三个主要组件：

shard：分片服务器，用于存储实际的数据块，由多台服务器组成一个复制集承担，防止主机单点故障

config server：配置服务器，存储整个分片群集的配置信息，包括块信息

routers：前端路由，客户端由此进入，让整个群集看上去像单一数据库

如何部署MongoDB分片群集！！！

1、安装MongoDB3.2版本包和openssl-devel包

[root@localhost ~]# yum install openssl-devel -y

[root@localhost ~]# mkdir /abc
[root@localhost ~]# mount.cifs //192.168.200.1/orc /abc
Password for root@//192.168.200.1/orc:
[root@localhost ~]# cd /abc
[root@localhost abc]# ls
mongodb-linux-x86_64-3.2.1.tgz  //MongoDB 3.2版本
[root@localhost abc]# tar zxvf mongodb-linux-x86_64-3.2.1.tgz -C /opt
[root@localhost abc]# cd /opt
[root@localhost opt]# ls
mongodb-linux-x86_64-3.2.1  rh
[root@localhost opt]# mv mongodb-linux-x86_64-3.2.1/ /usr/local/mongodb                 

[root@localhost opt]# cd /usr/local/bin/
[root@localhost bin]# ln -s /usr/local/mongodb/bin/mongo /usr/bin/mongo //建立软连接
[root@localhost bin]# ln -s /usr/local/mongodb/bin/mongod /usr/bin/mongod

[root@localhost bin]# mkdir -p /data/mongodb/mongodb{1,2,3,4}
[root@localhost bin]# mkdir /data/mongodb/logs
[root@localhost bin]# touch /data/mongodb/logs/mongodb{1,2,3,4}.log
[root@localhost bin]# chmod -R 777 /data/mongodb/logs/*.log

[root@localhost bin]# ulimit -n 25000   //打开文件数量
[root@localhost bin]# ulimit -u 25000    //进程并发数

2、部署配置服务器

编辑mongodb1.conf配置文件，端口为37017，设置configsvr=true，启动配置服务器

[root@localhost bin]# vim mongodb1.con
port=37017
dbpath=/data/mongodb/mongodb1
logpath=/data/mongodb/logs/mongodb1.log
logappend=true
fork=true
maxConns=5000
storageEngine=mmapv1
configsvr=true                //开启配置服务器

3、某节点内存不足，从其它节点分配内存

[root@localhost bin]# sysctl -w vm.zone_reclaim_mode=0
vm.zone_reclaim_mode = 0
[root@localhost bin]# echo never > /sys/kernel/mm/transparent_hugepage/enabled
[root@localhost bin]# echo never > /sys/kernel/mm/transparent_hugepage/defrag

[root@localhost bin]# mongod -f mongodb1.conf
about to fork child process, waiting until server is ready for connections.
forked process: 6895
child process started successfully, parent exiting

4、部署分片服务器

编辑mongodb2.conf配置文件，端口为47017，设置shardsvr=true；编辑mongodb3.conf配置文件，端口为47018，启动两个分片服务器

[root@localhost bin]# cp -p mongodb1.conf mongodb2.conf 

[root@localhost bin]# vim mongodb2.conf
port=47017                   //修改端口
dbpath=/data/mongodb/mongodb2
logpath=/data/mongodb/logs/mongodb2.log
logappend=true
fork=true
maxConns=5000
storageEngine=mmapv1
shardsvr=true                //开启分片服务器

[root@localhost bin]# cp -p mongodb2.conf mongodb3.conf
[root@localhost bin]# vim mongodb3.conf
port=47018
dbpath=/data/mongodb/mongodb3
logpath=/data/mongodb/logs/mongodb3.log
logappend=true
fork=true
maxConns=5000
storageEngine=mmapv1
shardsvr=true

[root@localhost bin]# mongod -f mongodb2.conf
about to fork child process, waiting until server is ready for connections.
forked process: 7080
child process started successfully, parent exiting
[root@localhost bin]# mongod -f mongodb3.conf
about to fork child process, waiting until server is ready for connections.
forked process: 7107
child process started successfully, parent exiting

[root@localhost bin]# netstat -antp | grep mongod
tcp        0      0 0.0.0.0:37017           0.0.0.0:*               LISTEN      god
tcp        0      0 0.0.0.0:47017           0.0.0.0:*               LISTEN      god
tcp        0      0 0.0.0.0:47018           0.0.0.0:*               LISTEN      god  

5、启动路由服务器

./mongos --help命令可以查看路由相关参数信息。chunkSize为数据块大小，默认为200M，这里将值设为1

[root@localhost bin]# ./mongos --port 27017 --fork --logpath=/usr/local/mongodb/bin/route.log --configdb 192.168.200.142:37017 --chunkSize 1

6、启用分片服务器

mongos> sh.addShard("192.168.200.142:47017")
{ "shardAdded" : "shard0000", "ok" : 1 }
mongos> sh.addShard("192.168.200.142:47018")
{ "shardAdded" : "shard0001", "ok" : 1 }
mongos> sh.status()
--- Sharding Status ---
  sharding version: {
    "_id" : 1,
    "minCompatibleVersion" : 5,
    "currentVersion" : 6,
    "clusterId" : ObjectId("5b4f68599dcf397cc4e7c598")
}
  shards:                 //分片服务器开启
    {  "_id" : "shard0000",  "host" : "192.168.200.142:47017" }
    {  "_id" : "shard0001",  "host" : "192.168.200.142:47018" }
  active mongoses:
    "3.2.1" : 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 migratio

7、分片功能

[root@localhost bin]# mongo
mongos> use school
switched to db school

mongos> for(var i=1;i<=10000;i++)db.users.insert({"id":i,"name":"jack"+i})
WriteResult({ "nInserted" : 1 })

mongos> show dbs
config  0.031GB
school  0.078GB             

mongos> use school
switched to db school

mongos> show collections
system.indexes
users

mongos> db.users.find().limit(10)  //查看头十行内容
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4ae"), "id" : 1, "name" : "jack1" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4af"), "id" : 2, "name" : "jack2" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4b0"), "id" : 3, "name" : "jack3" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4b1"), "id" : 4, "name" : "jack4" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4b2"), "id" : 5, "name" : "jack5" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4b3"), "id" : 6, "name" : "jack6" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4b4"), "id" : 7, "name" : "jack7" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4b5"), "id" : 8, "name" : "jack8" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4b6"), "id" : 9, "name" : "jack9" }
{ "_id" : ObjectId("5b4f6a24ef33d588c0dbc4b7"), "id" : 10, "name" : "jack10" }

mongos> sh.status()             //查看数据库分片信息
--- Sharding Status ---
  sharding version: {
    "_id" : 1,
    "minCompatibleVersion" : 5,
    "currentVersion" : 6,
    "clusterId" : ObjectId("5b4f68599dcf397cc4e7c598")
}
  shards:
    {  "_id" : "shard0000",  "host" : "192.168.200.142:47017" }
    {  "_id" : "shard0001",  "host" : "192.168.200.142:47018" }
  active mongoses:
    "3.2.1" : 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:
    {  "_id" : "school",  "primary" : "shard0000",  "partitioned" : false }

mongos> sh.enableSharding("school") //启用数据库分片
{ "ok" : 1 }

mongos> sh.status()
--- Sharding Status ---
  sharding version: {
    "_id" : 1,
    "minCompatibleVersion" : 5,
    "currentVersion" : 6,
    "clusterId" : ObjectId("5b4f68599dcf397cc4e7c598")
}
  shards:
    {  "_id" : "shard0000",  "host" : "192.168.200.142:47017" }
    {  "_id" : "shard0001",  "host" : "192.168.200.142:47018" }
  active mongoses:
    "3.2.1" : 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:
    {  "_id" : "school",  "primary" : "shard0000",  "partitioned" : true }

mongos> db.users.createIndex({"id":1})  //对users表创建索引
{
    "raw" : {
        "192.168.200.142:47017" : {
            "createdCollectionAutomatically" : false,
            "numIndexesBefore" : 1,
            "numIndexesAfter" : 2,
            "ok" : 1
        }
    },
    "ok" : 1
}

mongos> sh.shardCollection("school.users",{"id":1})//表分片
{ "collectionsharded" : "school.users", "ok" : 1 }

mongos> sh.status()
--- Sharding Status ---
  sharding version: {
    "_id" : 1,
    "minCompatibleVersion" : 5,
    "currentVersion" : 6,
    "clusterId" : ObjectId("5b4f68599dcf397cc4e7c598")
}
  shards:
    {  "_id" : "shard0000",  "host" : "192.168.200.142:47017" }
    {  "_id" : "shard0001",  "host" : "192.168.200.142:47018" }
  active mongoses:
    "3.2.1" : 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:
    {  "_id" : "school",  "primary" : "shard0000",  "partitioned" : true }
        school.users
            shard key: { "id" : 1 }
            unique: false
            balancing: true
            chunks:
                shard0000   3
            { "id" : { "$minKey" : 1 } } -->> { "id" : 4682 } on : shard0000 Timestamp(1, 0)
            { "id" : 4682 } -->> { "id" : 9364 } on : shard0000 Timestamp(1, 1)
            { "id" : 9364 } -->> { "id" : { "$maxKey" : 1 } } on : shard0000 Timestamp(1, 2)        //分片成功