Mongodb分片集羣介紹
分片（sharding）是指將數據庫拆分，將其分散在不同的機器上的過程。將數據分散到不同的機器上，不需要功能強大的服務器就可以存儲更多的數據和處理更大的負載。基本思想就是將集合切成小塊，這些塊分散到若干片裏，每個片只負責總數據的一部分，最後通過一個均衡器來對各個分片進行均衡（數據遷移）。通過一個名爲mongos的路由進程進行操作，mongos知道數據和片的對應關係（通過配置服務器）。大部分使用場景都是解決磁盤空間的問題，對於寫入有可能會變差，查詢則儘量避免跨分片查詢。使用分片的時機：
1，機器的磁盤不夠用了。使用分片解決磁盤空間的問題。
2，單個mongod已經不能滿足寫數據的性能要求。通過分片讓寫壓力分散到各個分片上面，使用分片服務器自身的資源。
3，想把大量數據放到內存裏提高性能。和上面一樣，通過分片使用分片服務器自身的資源。
服務器規劃
下載 Mongodb
https://www.mongodb.com/download-center/community
wget -c https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-rhel70-4.0.8.tgz
解壓包 Mongodb 包
tar -zxvf mongodb-linux-x86_64-rhel70-4.0.7.tgz -C /usr/local/mongodb
添加環境變量
export MONGO_HOME=/usr/local/mongodb export PATH=$PATH:$MONGO_HOME/bin
集羣準備
新建 Mongodb 需要的目錄
在192.168.2.177服務器上操作，以下配置操作均在192.168.2.177上進行
mkdir -p /wdata/mongodb/{data,logs,config,keys}
mkdir -p /wdata/mongodb/data/{mongosrv,shard1}將新建的目錄發送到另外兩臺服務器
for i in 178 180; do scp -r /wdata/mongodb [email protected].$i; done
生成分片集羣的key文件
openssl rand -base64 90 -out /wdata/mongodb/keys/keyfile
修改key文件屬性
chmod 600 /wdata/mongodb/keys/keyfile
注意：此處必須修改，否則可能報錯
編輯 mongos.conf 文件
systemLog: destination: file #日誌存儲位置 path: /wdata/mongodb/logs/mongos.log logAppend: true processManagement: #fork and run in background fork: true pidFilePath: /wdata/mongodb/data/mongos.pid #端口配置 net: port: 30000 maxIncomingConnections: 500 unixDomainSocket: enabled: true #pathPrefix: /tmp filePermissions: 0700 bindIp: 0.0.0.0 security: keyFile: /wdata/mongodb/keys/keyfile #將 confige server 添加到路由 sharding: configDB: configs/192.168.2.177:21000,192.168.2.178:21000,192.168.2.180:21000
編輯 mongosrv1.conf 文件
systemLog: destination: file logAppend: true path: /wdata/mongodb/logs/mongosrv.log storage: dbPath: /wdata/mongodb/data/mongosrv journal: enabled: true wiredTiger: engineConfig: directoryForIndexes: true processManagement: # fork and run in background fork: true # location of pidfile pidFilePath: /wdata/mongodb/data/mongosrv/mongosrv.pid net: port: 21000 #bindIp: 0.0.0.0 # Enter 0.0.0.0,:: to bind to all IPv4 and IPv6 addresses or, alternatively, use the net.bindIpAll setting. bindIpAll: true maxIncomingConnections: 65535 unixDomainSocket: enabled: true filePermissions: 0700 security: keyFile: /wdata/mongodb/keys/keyfile authorization: enabled replication: replSetName: configs sharding: clusterRole: configsvr
說明：該文件在此環境需要3個，分佈在3臺服務器，這裏僅配置1個
編輯 shard1.conf 文件
systemLog: destination: file logAppend: true path: /wdata/mongodb/logs/shard1.log storage: dbPath: /wdata/mongodb/data/shard1 journal: enabled: true wiredTiger: engineConfig: directoryForIndexes: true processManagement: # fork and run in background fork: true pidFilePath: /wdata/mongodb/data/mongosrv/mongosrv.pid # location of pidfile # timeZoneInfo: /usr/share/zoneinfo net: port: 27001 # bindIp: 0.0.0.0 # Enter 0.0.0.0,:: to bind to all IPv4 and IPv6 addresses or, alternatively, use the net.bindIpAll setting. bindIpAll: true maxIncomingConnections: 65535 unixDomainSocket: enabled: true # pathPrefix: /tmp/mongod1 filePermissions: 0700 security: keyFile: /wdata/mongodb/keys/keyfile authorization: enabled replication: replSetName: shard1 sharding: clusterRole: shardsvr
說明：shard在一臺服務器上也可以配置多個，建不同的目錄充當分片服務器，看需求而定
將配置文件到其他兩臺服務器
for i in 178 180; do scp -r /wdata/mongodb/config [email protected].$i:/wdata/mongodb/; done
啓動集羣
在192.168.1.177上啓動 mongod -f /wdata/mongodb/config/mongosrv1.conf mongod -f /wdata/mongodb/config/shard1.conf mongos -f /wdata/mongodb/config/mongos.conf 在192.168.1.178上啓動 mongod -f /wdata/mongodb/config/mongosrv1.conf mongod -f /wdata/mongodb/config/shard1.conf mongos -f /wdata/mongodb/config/mongos.conf 在192.168.1.180上啓動 mongod -f /wdata/mongodb/config/mongosrv1.conf mongod -f /wdata/mongodb/config/shard1.conf mongos -f /wdata/mongodb/config/mongos.conf
分片集羣創建副本集
在192.168.2.177上操作
[root@localhost mongodb]# mongo --port 27001
MongoDB shell version v4.0.7
connecting to: mongodb://127.0.0.1:27001/?gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("b56157d2-fbc7-4226-aeb4-4de0b79dfcda") }
MongoDB server version: 4.0.7
> use admin
switched to db admin
> config = {_id: 'shard1', members: [{_id: 0, host: '192.168.2.177:27001'},{_id: 1, host: '192.168.2.178:27001'},{_id: 2, host:'192.168.2.180:27001'}]}
{
"_id" : "shard1",
"members" : [
{
"_id" : 0,
"host" : "192.168.2.177:27001"
},
{
"_id" : 1,
"host" : "192.168.2.178:27001"
},
{
"_id" : 2,
"host" : "192.168.2.180:27001"
}
]
}
> rs.initiate(config)
{ "ok" : 1 }
shard1:PRIMARY> rs.status()
{
"set" : "shard1",
"date" : ISODate("2019-04-03T10:08:16.477Z"),
"myState" : 1,
"term" : NumberLong(1),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"heartbeatIntervalMillis" : NumberLong(2000),
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
},
"readConcernMajorityOpTime" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
},
"appliedOpTime" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
},
"durableOpTime" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
}
},
"lastStableCheckpointTimestamp" : Timestamp(1554286040, 2),
"members" : [
{
"_id" : 0,
"name" : "192.168.2.177:27001",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 2657,
"optime" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2019-04-03T10:08:10Z"),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "could not find member to sync from",
"electionTime" : Timestamp(1554286040, 1),
"electionDate" : ISODate("2019-04-03T10:07:20Z"),
"configVersion" : 1,
"self" : true,
"lastHeartbeatMessage" : ""
},
{
"_id" : 1,
"name" : "192.168.2.178:27001",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 67,
"optime" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2019-04-03T10:08:10Z"),
"optimeDurableDate" : ISODate("2019-04-03T10:08:10Z"),
"lastHeartbeat" : ISODate("2019-04-03T10:08:16.259Z"),
"lastHeartbeatRecv" : ISODate("2019-04-03T10:08:15.440Z"),
"pingMs" : NumberLong(6),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.2.177:27001",
"syncSourceHost" : "192.168.2.177:27001",
"syncSourceId" : 0,
"infoMessage" : "",
"configVersion" : 1
},
{
"_id" : 2,
"name" : "192.168.2.180:27001",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 67,
"optime" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1554286090, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2019-04-03T10:08:10Z"),
"optimeDurableDate" : ISODate("2019-04-03T10:08:10Z"),
"lastHeartbeat" : ISODate("2019-04-03T10:08:16.219Z"),
"lastHeartbeatRecv" : ISODate("2019-04-03T10:08:15.440Z"),
"pingMs" : NumberLong(4),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.2.177:27001",
"syncSourceHost" : "192.168.2.177:27001",
"syncSourceId" : 0,
"infoMessage" : "",
"configVersion" : 1
}
],
"ok" : 1
}
shard1:PRIMARY> exit
bye創建分片集羣數據庫和用戶
[root@localhost mongodb]# mongo --port 27001
MongoDB shell version v4.0.7
connecting to: mongodb://127.0.0.1:27001/?gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("a4c12af4-85e2-49e3-9a02-dd481307bcda") }
MongoDB server version: 4.0.7
shard1:PRIMARY> use admin
switched to db admin
shard1:PRIMARY> db.createUser({user:"admin",pwd:"123456",roles:[{role:"userAdminAnyDatabase",db:"admin"}]})
Successfully added user: {
"user" : "admin",
"roles" : [
{
"role" : "userAdminAnyDatabase",
"db" : "admin"
}
]
}
shard1:PRIMARY> db.auth("admin","123456")
1
shard1:PRIMARY> use test
switched to db test
shard1:PRIMARY> db.createUser({user:"root",pwd:"123456",roles:[{role:"dbOwner",db:"test"}]})
Successfully added user: {
"user" : "root",
"roles" : [
{
"role" : "dbOwner",
"db" : "test"
}
]
}
shard1:PRIMARY> exit
bye配置 mongosrv 副本集
[root@localhost config]# mongo --port 21000
MongoDB shell version v4.0.7
connecting to: mongodb://127.0.0.1:21000/?gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("f9896034-d90f-4d52-bc55-51c3dc85aae9") }
MongoDB server version: 4.0.7
> config = {_id: 'configs', members: [{_id: 0, host: '192.168.2.177:21000'},{_id: 1, host: '192.168.2.178:21000'},{_id: 2, host: '192.168.2.180:21000'}]}
{
"_id" : "configs",
"members" : [
{
"_id" : 0,
"host" : "192.168.2.177:21000"
},
{
"_id" : 1,
"host" : "192.168.2.178:21000"
},
{
"_id" : 2,
"host" : "192.168.2.180:21000"
}
]
}
> rs.initiate(config)
{
"ok" : 1,
"$gleStats" : {
"lastOpTime" : Timestamp(1554288851, 1),
"electionId" : ObjectId("000000000000000000000000")
},
"lastCommittedOpTime" : Timestamp(0, 0)
}
configs:SECONDARY> rs.status(config)
{
"set" : "configs",
"date" : ISODate("2019-04-03T10:54:43.283Z"),
"myState" : 1,
"term" : NumberLong(1),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"configsvr" : true,
"heartbeatIntervalMillis" : NumberLong(2000),
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
},
"readConcernMajorityOpTime" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
},
"appliedOpTime" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
},
"durableOpTime" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
}
},
"lastStableCheckpointTimestamp" : Timestamp(1554288864, 1),
"members" : [
{
"_id" : 0,
"name" : "192.168.2.177:21000",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 5454,
"optime" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2019-04-03T10:54:39Z"),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "could not find member to sync from",
"electionTime" : Timestamp(1554288863, 1),
"electionDate" : ISODate("2019-04-03T10:54:23Z"),
"configVersion" : 1,
"self" : true,
"lastHeartbeatMessage" : ""
},
{
"_id" : 1,
"name" : "192.168.2.178:21000",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 31,
"optime" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2019-04-03T10:54:39Z"),
"optimeDurableDate" : ISODate("2019-04-03T10:54:39Z"),
"lastHeartbeat" : ISODate("2019-04-03T10:54:41.362Z"),
"lastHeartbeatRecv" : ISODate("2019-04-03T10:54:41.906Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.2.177:21000",
"syncSourceHost" : "192.168.2.177:21000",
"syncSourceId" : 0,
"infoMessage" : "",
"configVersion" : 1
},
{
"_id" : 2,
"name" : "192.168.2.180:21000",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 31,
"optime" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1554288879, 4),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2019-04-03T10:54:39Z"),
"optimeDurableDate" : ISODate("2019-04-03T10:54:39Z"),
"lastHeartbeat" : ISODate("2019-04-03T10:54:41.362Z"),
"lastHeartbeatRecv" : ISODate("2019-04-03T10:54:41.597Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.2.177:21000",
"syncSourceHost" : "192.168.2.177:21000",
"syncSourceId" : 0,
"infoMessage" : "",
"configVersion" : 1
}
],
"ok" : 1,
"operationTime" : Timestamp(1554288879, 4),
"$gleStats" : {
"lastOpTime" : Timestamp(1554288851, 1),
"electionId" : ObjectId("7fffffff0000000000000001")
},
"lastCommittedOpTime" : Timestamp(1554288879, 4),
"$clusterTime" : {
"clusterTime" : Timestamp(1554288879, 4),
"signature" : {
"hash" : BinData(0,"VVM2Bsa9KiZy8Sew9Oa8CsbDBPU="),
"keyId" : NumberLong("6675619852301893642")
}
}
}
configs:PRIMARY>到此mongodb分片集羣部署完成後，後面附上 Mongodb 常見操作指令
show dbs #查看所有數據庫
db #查看當前所在的數據庫
sh.status() #查看集羣的信息
sh.enableSharding("dba") #對數據庫啓用分片
db.help() #查看幫助
db.account.stats() #查看數據集合的分佈情況
db.createUser() #新建用戶
use databasename #進入或者新建數據庫
db.shutdownServer() #關閉數據庫
db.dropDatabase() #刪除數據庫（必須先切換到該數據庫）