1. Index
1. Index operation
1.1 Insert data
> use testdb
switched to db testdb
> for (i=1;i<=10000;i++) db.students.insert({name:"student"+i,age:(i%120),address:"#85 Wenhua Road,Zhengzhou,China"})
> db.students.find().count()
10000
1.2 Create an index
在name字段构建升序索引：
> db.students.ensureIndex({name: 1})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 1,
"numIndexesAfter" : 2,
"ok" : 1
}
查看索引：
> db.students.getIndexes()
[
{
"v" : 1,
"key" : {
"_id" : 1
},
"name" : "_id_",
"ns" : "testdb.students"
},
{
"v" : 1,
"key" : {
"name" : 1
},
"name" : "name_1",
"ns" : "testdb.students"
}
]
1.3 delete index
> db.students.dropIndex("name_1")
{ "nIndexesWas" : 2, "ok" : 1 }
> db.students.getIndexes()
[
{
"v" : 1,
"key" : {
"_id" : 1
},
"name" : "_id_",
"ns" : "testdb.students"
}
]
>
1.4 Create a unique key index
> db.students.ensureIndex({name: 1},{unique: true})
> db.students.getIndexes()
{
"v" : 1,
"unique" : true,
"key" : {
"name" : 1
},
"name" : "name_1",
"ns" : "testdb.students"
插入同样的值会有约束：
> db.students.insert({name: "student20",age: 20})
WriteResult({
"nInserted" : 0,
"writeError" : {
"code" : 11000,
"errmsg" : "E11000 duplicate key error index: testdb.students.$name_1 dup key: { : \"student20\" }"
}
})
1.5 View the detailed execution process of the find statement
> db.students.find({name: "student5000"}).explain("executionStats")
{
"queryPlanner" : {
"plannerVersion" : 1,
"namespace" : "testdb.students",
"indexFilterSet" : false,
"parsedQuery" : {
"name" : {
"$eq" : "student5000"
}
},
"winningPlan" : {
"stage" : "FETCH",
"inputStage" : {
"stage" : "IXSCAN",
"keyPattern" : {
"name" : 1
},
"indexName" : "name_1",
"isMultiKey" : false,
"direction" : "forward",
"indexBounds" : {
"name" : [
"[\"student5000\", \"student5000\"]"
]
}
}
},
"rejectedPlans" : [ ]
},
"serverInfo" : {
"host" : "master1.com",
"port" : 27017,
"version" : "3.0.0",
"gitVersion" : "a841fd6394365954886924a35076691b4d149168"
},
"ok" : 1
}
查看大于5000的记录执行过程
db.students.find({name: {$gt: "student5000"}}).explain("executionStats")
在15万条记录中查找name大于8万的记录，不做索引和做所用对比。
> for (i=1;i<=150000;i++) db.test.insert({name:"student"+i,age:(i%120),address:"#85 Wenhua Road,Zhengzhou,China"})
查找：
db.test.find({name: {$gt: "student80000"}}).explain("executionStats")
对比截图，左边是全表查找，右边是添加索引后查找
2. MongoDB replica set
1. mongod replica set configuration
1.1 Miscellaneous
主节点将数据修改操作保存至oplog中，从节点通过oplog复制到本地并应用。oplog一般存储在local数据库
> show dbs
local 0.078GB
testdb 0.078GB
> use local
switched to db local
> show collections
startup_log
system.indexes
只有启动副本集，才会产生相关的文件
1.2 Prepare three nodes
master1（主节点）,2,3
1.3 Install MongoDB
master2,3安装MongoDB
[root@master2 mongodb-3.0.0]# ls
mongodb-org-server-3.0.0-1.el7.x86_64.rpm
mongodb-org-shell-3.0.0-1.el7.x86_64.rpm
mongodb-org-tools-3.0.0-1.el7.x86_64.rpm
[root@master2 mongodb-3.0.0]# yum install *.rpm
master2配置：
[root@master2 ~]# mkdir -pv /mongodb/data
[root@master2 ~]# chown -R mongod.mongod /mongodb/
从master1拷贝配置到master2,并修改
[root@master1 ~]# scp /etc/mongod.conf root@master2:/etc/
[root@master1 ~]# scp /etc/mongod.conf root@master3:/etc/
启动服务：
[root@master2 ~]# systemctl start mongod.service
master3同上配置，并启动mongod服务。
1.4 Master node configuration
先停止刚才master1的mongod服务：
[root@master1 ~]# systemctl stop mongod.service
启动主节点复制集功能
[root@master1 ~]# vim /etc/mongod.conf
replSet=testSet #复制集名称
replIndexPrefetch=_id_only
重新启动服务：
[root@master1 ~]# systemctl start mongod.service
查看：
[root@master1 ~]# mongo
1.5 Primary node (master1), replication set initialization
获取复制命令相关帮助：
> rs.help()
主节点复制集初始化
> rs.initiate()
主节点rs状态：
> rs.initiate()
{
"info2" : "no configuration explicitly specified -- making one",
"me" : "master1.com:27017",
"ok" : 1
}
testSet:OTHER>
testSet:PRIMARY> rs.status()
{
"set" : "testSet", #复制集名称
"date" : ISODate("2017-01-16T14:36:29.948Z"),
"myState" : 1,
"members" : [
{
"_id" : 0, #节点标识
"name" : "master1.com:27017", #节点名称
"health" : 1, #节点健康状态
"state" : 1, #有没有状态信息
"stateStr" : "PRIMARY", #节点角色
"uptime" : 790, #运行时长
"optime" : Timestamp(1484577363, 1), #最后一次oplog时间戳
"optimeDate" : ISODate("2017-01-16T14:36:03Z"), #最后一次oplog时间
"electionTime" : Timestamp(1484577363, 2), #选举时间戳
"electionDate" : ISODate("2017-01-16T14:36:03Z"), #选举时间
"configVersion" : 1,
"self" : true #是不是当前节点
}
],
"ok" : 1
}
主节点rs配置：
testSet:PRIMARY> rs.conf()
{
"_id" : "testSet",
"version" : 1,
"members" : [
{
"_id" : 0,
"host" : "master1.com:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : 0,
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatTimeoutSecs" : 10,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
}
}
}
1.6 Add a slave node to the master node
testSet:PRIMARY> rs.add("10.201.106.132")
{ "ok" : 1 }
查看
testSet:PRIMARY> rs.status()
{
"_id" : 1,
"name" : "10.201.106.132:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 35,
"optime" : Timestamp(1524666332, 1),
"optimeDate" : ISODate("2018-04-25T14:25:32Z"),
"lastHeartbeat" : ISODate("2018-04-25T14:26:07.009Z"),
"lastHeartbeatRecv" : ISODate("2018-04-25T14:26:07.051Z"),
"pingMs" : 0,
"configVersion" : 2
}
],
master2（从节点）查看：
[root@master2 ~]# mongo
遇到报错：
Error: listDatabases failed:{ "note" : "from execCommand", "ok" : 0, "errmsg" : "not master" }
解决办法
执行 rs.slaveOk()方法
查看：
testSet:SECONDARY> show dbs
local 2.077GB
testdb 0.078GB
testSet:SECONDARY> use testdb
switched to db testdb
testSet:SECONDARY> db.students.findOne()
{
"_id" : ObjectId("587c9032fe3baa930c0f51d9"),
"name" : "student1",
"age" : 1,
"address" : "#85 Wenhua Road,Zhengzhou,China"
}
查看谁是主节点：
testSet:SECONDARY> rs.isMaster()
{
"setName" : "testSet",
"setVersion" : 2,
"ismaster" : false,
"secondary" : true,
"hosts" : [
"master1.com:27017",
"10.201.106.132:27017"
],
"primary" : "master1.com:27017", ###
"me" : "10.201.106.132:27017", ###
"maxBsonObjectSize" : 16777216,
"maxMessageSizeBytes" : 48000000,
"maxWriteBatchSize" : 1000,
"localTime" : ISODate("2018-04-25T14:43:35.956Z"),
"maxWireVersion" : 3,
"minWireVersion" : 0,
"ok" : 1
}
主节点添加第三个节点（master3）
[root@master1 ~]# mongo
testSet:PRIMARY> rs.add("10.201.106.133")
{ "ok" : 1 }
从节点（master3）配置成可用节点：
[root@master3 ~]# mongo
testSet:SECONDARY> rs.slaveOk()
testSet:SECONDARY> use testdb
switched to db testdb
testSet:SECONDARY> db.students.findOne()
{
"_id" : ObjectId("587c9032fe3baa930c0f51d9"),
"name" : "student1",
"age" : 1,
"address" : "#85 Wenhua Road,Zhengzhou,China"
}
一旦添加从节点，从节点会自动克隆主节点的所有数据库后，并开始复制主节点的oplog，并应用于本地并为collection构建索引。
1.7 View rs configuration
testSet:SECONDARY> rs.conf()
1.8 The master node writes data and tests synchronization
testSet:PRIMARY> db.classes.insert({class: "One",nostu: 40})
从节点查看：
testSet:SECONDARY> db.classes.findOne()
{
"_id" : ObjectId("5ae09653f7aa5c90df36dc59"),
"class" : "One",
"nostu" : 40
}
从节点禁止插入数据：
testSet:SECONDARY> db.classes.insert({class: "Tow",nostu: 50})
WriteResult({ "writeError" : { "code" : undefined, "errmsg" : "not master" } })
1.9 The main node is down, test switching
主节点手动down
testSet:PRIMARY> rs.stepDown()
重新查看状态，master3已经成为主节点：
testSet:SECONDARY> rs.status()
master3查看，状态已经改变：
testSet:SECONDARY>
testSet:PRIMARY>
2. Other
2.1 View oplog size and synchronization time
testSet:PRIMARY> db.printReplicationInfo()
configured oplog size: 1165.03515625MB
log length start to end: 390secs (0.11hrs)
oplog first event time: Wed Apr 25 2018 22:46:37 GMT+0800 (CST)
oplog last event time: Wed Apr 25 2018 22:53:07 GMT+0800 (CST)
now: Wed Apr 25 2018 23:32:35 GMT+0800 (CST)
2.2 Modify the priority of master2 to become the master node first
rs.conf()对应的collection是local.system.replset
local.system.replset.members[n].priority
需要在主节点操作***
先将配置导入cfg变量
testSet:SECONDARY> cfg=rs.conf()
然后修改值（ID号默认从0开始）：
testSet:SECONDARY> cfg.members[1].priority=2
2
重新加载配置
testSet:SECONDARY> rs.reconfig(cfg)
{ "ok" : 1 }
重载后master2自动变成主节点，master3变回从节点
2.3 Modify master3 to be a pure arbitration node
需要在主节点配置***
需要先将master3的从节点角色移除：
testSet:PRIMARY> rs.remove("10.201.106.133:27017")
{ "ok" : 1 }
修改master3为仲裁节点：
testSet:PRIMARY> rs.addArb("10.201.106.133")
{ "ok" : 1 }
testSet:PRIMARY> rs.status()
{
"_id" : 2,
"name" : "10.201.106.133:27017",
"health" : 1,
"state" : 7,
"stateStr" : "ARBITER",
"uptime" : 21,
"lastHeartbeat" : ISODate("2018-04-25T16:06:39.938Z"),
"lastHeartbeatRecv" : ISODate("2018-04-25T16:06:39.930Z"),
"pingMs" : 0,
"syncingTo" : "master1.com:27017",
"configVersion" : 6
}
2.4 View slave information
testSet:PRIMARY> rs.printSlaveReplicationInfo()
source: master1.com:27017
syncedTo: Thu Apr 26 2018 00:50:53 GMT+0800 (CST)
0 secs (0 hrs) behind the primary
source: 10.201.106.133:27017
syncedTo: Wed Apr 25 2018 23:53:51 GMT+0800 (CST)
3422 secs (0.95 hrs) behind the primary
3. MongoDB sharding
In the production environment, it is recommended to use a pair of mongos servers for high availability through keepalived, at least three config servers to implement the arbitration function, and multiple shard nodes
1. Sharding (master1: mongos, master2: config server, master3, 4: shard), test environment
1.1 Environment Preparation
停止之前的服务：
[root@master1 ~]# systemctl stop mongod
[root@master2 ~]# systemctl stop mongod
[root@master3 ~]# systemctl stop mongod
删除之前的数据：
[root@master1 ~]# rm -rf /mongodb/data/*
[root@master2 ~]# rm -rf /mongodb/data/*
[root@master3 ~]# rm -rf /mongodb/data/*
4个节点时间同步：
/usr/sbin/ntpdate ntp1.aliyun.com
master4安装MongoDB
[root@master4 mongodb-3.0.0]# ls
mongodb-org-server-3.0.0-1.el7.x86_64.rpm mongodb-org-tools-3.0.0-1.el7.x86_64.rpm
mongodb-org-shell-3.0.0-1.el7.x86_64.rpm
[root@master4 mongodb-3.0.0]# yum install -y *.rpm
[root@master4 ~]# mkdir -pv /mongodb/data
[root@master4 ~]# chown -R mongod:mongod /mongodb/
1.2 First configure config-server (master2)
[root@master2 ~]# vim /etc/mongod.conf
#注释刚才的复制集配置
#replSet=testSet
#replIndexPrefetch=_id_only
dbpath=/mongodb/data
#配置该节点为config-server
configsvr=true
启动mongod：
[root@master2 ~]# systemctl start mongod
监听端口：
[root@master2 ~]# netstat -tanp | grep mongod
tcp 0 0 0.0.0.0:27019 0.0.0.0:* LISTEN 24036/mongod
tcp 0 0 0.0.0.0:28019 0.0.0.0:* LISTEN 24036/mongod
1.3 mongos (master1) configuration
安装mongos包：
[root@master1 mongodb-3.0.0]# yum install mongodb-org-mongos-3.0.0-1.el7.x86_64.rpm
通过命令启动，指向config服务器，并运行在后台：
[root@master1 ~]# mongos --configdb=10.201.106.132 --fork --logpath=/var/log/mongodb/mongos.log
查看监听端口：
[root@master1 ~]# netstat -tanp | grep mon
tcp 0 0 0.0.0.0:27017 0.0.0.0:* LISTEN 27801/mongos
tcp 0 0 10.201.106.131:60956 10.201.106.132:27019 ESTABLISHED 27801/mongos
tcp 0 0 10.201.106.131:60955 10.201.106.132:27019 ESTABLISHED 27801/mongos
tcp 0 0 10.201.106.131:60958 10.201.106.132:27019 ESTABLISHED 27801/mongos
tcp 0 0 10.201.106.131:60957 10.201.106.132:27019 ESTABLISHED 27801/mongos
连接：
[root@master1 ~]# mongo
查看当前shard状态信息：
mongos> sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("5ae16bddf4bf9c27f1816692")
}
shards:
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" : "admin", "partitioned" : false, "primary" : "config" }
1.4 Configuring shard nodes
master3配置：
[root@master3 ~]# vim /etc/mongod.conf
#取消刚才的复制集配置
#replSet=testSet
#replIndexPrefetch=_id_only
#其他配置不变
dbpath=/mongodb/data
#bind_ip=127.0.0.1
启动服务：
[root@master3 ~]# systemctl start mongod
master4：
[root@master4 ~]# vim /etc/mongod.conf
dbpath=/mongodb/data
#注释127.0.0.1的配置，服务会自动监听0.0.0.0地址
#bind_ip=127.0.0.1
启动服务：
[root@master4 ~]# systemctl start mongod
1.5 Add a shard node on mongos (master1)
[root@master1 ~]# mongo
添加第一个shard节点
mongos> sh.addShard("10.201.106.133")
{ "shardAdded" : "shard0000", "ok" : 1 }
查看状态
mongos> sh.status()
添加第二个shard节点：
mongos> sh.addShard("10.201.106.134")
{ "shardAdded" : "shard0001", "ok" : 1 }
1.6 Enable shard
shard是collection级别的，不分片的collection放在主shard上。
testdb数据库开启shard功能：
mongos> sh.enableSharding("testdb")
{ "ok" : 1 }
查看状态，testdb数据已经支持shard功能
mongos> sh .status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("5ae16bddf4bf9c27f1816692")
}
shards:
{ "_id" : "shard0000", "host" : "10.201.106.133:27017" }
{ "_id" : "shard0001", "host" : "10.201.106.134:27017" }
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" : "admin", "partitioned" : false, "primary" : "config" }
{ "_id" : "test", "partitioned" : false, "primary" : "shard0000" }
{ "_id" : "testdb", "partitioned" : true, "primary" : "shard0000" } #主shard
1.7 Collection enables fragmentation
students启动分片，根据age索引进行分配：
mongos> sh.shardCollection("testdb.students",{"age": 1})
{ "collectionsharded" : "testdb.students", "ok" : 1 }
查看：
mongos> sh .status()
创建数据（需要等待一段时间，可另开窗口查看db.students.find().count()
）：
mongos> use testdb
switched to db testdb
mongos> for (i=1;i<=100000;i++) db.students.insert({name:"students"+i,age:(i%120),classes:"class"+(i%10),address:"www.magedu.com,MageEdu,#85 Wenhua Road,Zhenzhou,China"})
查看状态，已经有5个分片，按照年龄段范围进行分片：
mongos> sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("5ae16bddf4bf9c27f1816692")
}
shards:
{ "_id" : "shard0000", "host" : "10.201.106.133:27017" }
{ "_id" : "shard0001", "host" : "10.201.106.134:27017" }
balancer:
Currently enabled: yes
Currently running: no
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
2 : Success
databases:
{ "_id" : "admin", "partitioned" : false, "primary" : "config" }
{ "_id" : "test", "partitioned" : false, "primary" : "shard0000" }
{ "_id" : "testdb", "partitioned" : true, "primary" : "shard0000" }
testdb.students
shard key: { "age" : 1 }
chunks:
shard0000 3 ###
shard0001 2 ###
{ "age" : { "$minKey" : 1 } } -->> { "age" : 2 } on : shard0001 Timestamp(2, 0)
{ "age" : 2 } -->> { "age" : 6 } on : shard0001 Timestamp(3, 0)
{ "age" : 6 } -->> { "age" : 54 } on : shard0000 Timestamp(3, 1)
{ "age" : 54 } -->> { "age" : 119 } on : shard0000 Timestamp(2, 3)
{ "age" : 119 } -->> { "age" : { "$maxKey" : 1 } } on : shard0000 Timestamp(2, 4)
1.8 View shard information
列出有几个shard
mongos> use admin
switched to db admin
mongos> db.runCommand("listShards")
{
"shards" : [
{
"_id" : "shard0000",
"host" : "10.201.106.133:27017"
},
{
"_id" : "shard0001",
"host" : "10.201.106.134:27017"
}
],
"ok" : 1
}
显示集群详细信息：
mongos> db.printShardingStatus()
shard帮助：
mongos> sh.help()
1.9 View the equalizer
查看均衡器是否工作（需要重新均衡时系统才会自动启动，不用管它）：
mongos> sh.isBalancerRunning()
false
查看当前Balancer状态：
mongos> sh.getBalancerState()
true
移动chunk（该操作会触发config-server更新元数据，不到万不得已建议不要手动移动chunk）：
mongos> sh.moveChunk("testdb.students",{Age: {$gt: 119}},"shard0000")