https://www.linode.com/docs/databases/mongodb/build-database-clusters-with-mongodb
由三部分组成
shard: 每个shard包括一个所有shard数据的子集. 每个shard能够部署成replica set
mongos: 做为查询路由, 提供clientt与sharded cluster的接口
config servers: 存储群集的metadata和配置，必须部署为replica set
# 生产环境部署
kvm-70-102 10.0.70.102 # mongos
kvm-70-103 10.0.70.103 # config
kvm-70-102 10.0.70.104 # shard1
kvm-70-103 10.0.70.105 # shard2
config
# 建立数据目录
mkdir -p /opt/mongo_{27021,27022,27023}
# 配置文件
cat > /etc/mongod_27021.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27021.log
storage:
dbPath: /opt/mongo_27021
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27021.pid
net:
port: 27021
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: config
sharding:
clusterRole: configsvr
EOF
# 配置文件
cat > /etc/mongod_27022.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27022.log
storage:
dbPath: /opt/mongo_27022
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27022.pid
net:
port: 27022
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: config
sharding:
clusterRole: configsvr
EOF
# 配置文件
cat > /etc/mongod_27023.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27023.log
storage:
dbPath: /opt/mongo_27023
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27023.pid
net:
port: 27023
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: config
sharding:
clusterRole: configsvr
EOF
# 启动复制集
mongod --config /etc/mongod_27021.conf
mongod --config /etc/mongod_27022.conf
mongod --config /etc/mongod_27023.conf
# 配置config
mongo --port 27021
rs.initiate(
{
_id: 'config',
configsvr: true,
members: [
{ _id : 0, host : '10.0.70.103:27021' },
{ _id : 1, host : '10.0.70.103:27022' },
{ _id : 2, host : '10.0.70.103:27023' }
]
}
)
{ "ok" : 1 }
shard1
# 建立数据目录
mkdir -p /opt/mongo_{27021,27022,27023}
# 配置文件
cat > /etc/mongod_27021.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27021.log
storage:
dbPath: /opt/mongo_27021
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27021.pid
net:
port: 27021
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: shard1
sharding:
clusterRole: shardsvr
EOF
# 配置文件
cat > /etc/mongod_27022.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27022.log
storage:
dbPath: /opt/mongo_27022
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27022.pid
net:
port: 27022
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: shard1
sharding:
clusterRole: shardsvr
EOF
# 配置文件
cat > /etc/mongod_27023.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27023.log
storage:
dbPath: /opt/mongo_27023
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27023.pid
net:
port: 27023
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: shard1
sharding:
clusterRole: shardsvr
EOF
# 启动复制集
mongod --config /etc/mongod_27021.conf
mongod --config /etc/mongod_27022.conf
mongod --config /etc/mongod_27023.conf
# 配置config
mongo --port 27021
rs.initiate(
{
_id: 'shard1',
members: [
{ _id : 0, host : '10.0.70.104:27021' },
{ _id : 1, host : '10.0.70.104:27022' },
{ _id : 2, host : '10.0.70.104:27023' }
]
}
)
{ "ok" : 1 }
shard2
# 建立数据目录
mkdir -p /opt/mongo_{27021,27022,27023}
# 配置文件
cat > /etc/mongod_27021.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27021.log
storage:
dbPath: /opt/mongo_27021
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27021.pid
net:
port: 27021
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: shard2
sharding:
clusterRole: shardsvr
EOF
# 配置文件
cat > /etc/mongod_27022.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27022.log
storage:
dbPath: /opt/mongo_27022
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27022.pid
net:
port: 27022
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: shard2
sharding:
clusterRole: shardsvr
EOF
# 配置文件
cat > /etc/mongod_27023.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27023.log
storage:
dbPath: /opt/mongo_27023
journal:
enabled: true
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27023.pid
net:
port: 27023
security:
keyFile: /etc/mongodb_product_key
replication:
oplogSizeMB: 2048
replSetName: shard2
sharding:
clusterRole: shardsvr
EOF
# 启动复制集
mongod --config /etc/mongod_27021.conf
mongod --config /etc/mongod_27022.conf
mongod --config /etc/mongod_27023.conf
# 配置config
mongo --port 27021
rs.initiate(
{
_id: 'shard2',
members: [
{ _id : 0, host : '10.0.70.105:27021' },
{ _id : 1, host : '10.0.70.105:27022' },
{ _id : 2, host : '10.0.70.105:27023' }
]
}
)
{ "ok" : 1 }
mongos
# 配置文件
cat > /etc/mongod_27021.conf << EOF
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod_27021.log
processManagement:
fork: true
pidFilePath: /var/run/mongodb/mongod_27021.pid
net:
port: 27021
security:
keyFile: /etc/mongodb_product_key
sharding:
configDB: config/10.0.70.103:27021,10.0.70.103:27022,10.0.70.103:27023
EOF
# 启动mongos
mongos --config /etc/mongod_27021.conf
# 配置
mongo --port 27021
# 添加分片
sh.addShard('shard1/10.0.70.104:27021')
sh.addShard('shard1/10.0.70.104:27022')
sh.addShard('shard1/10.0.70.104:27023')
sh.addShard('shard2/10.0.70.105:27021')
sh.addShard('shard2/10.0.70.105:27022')
sh.addShard('shard2/10.0.70.105:27023')
# 建立超级用户
use admin
db.createUser(
{
user: 'admin',
pwd: '@admin',
roles: [ { role: 'root', db: 'admin' } ]
}
);
# 认证登录
db.auth('admin', '@admin')
# app数据库demo表插入100000条数据
use app
for (var i = 1; i < 100000; i++) db.demo.insert({id: i, name: 'ken'})
WriteResult({ "nInserted" : 1 })
# 查看分片状态
sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("59261bca37ceff575b36ef09")
}
shards:
{ "_id" : "shard1", "host" : "shard1/10.0.70.104:27021,10.0.70.104:27022,10.0.70.104:27023", "state" : 1 }
{ "_id" : "shard2", "host" : "shard2/10.0.70.105:27021,10.0.70.105:27022,10.0.70.105:27023", "state" : 1 }
active mongoses:
"3.4.4" : 1
autosplit:
Currently enabled: yes
balancer:
Currently enabled: yes
Currently running: no
Balancer lock taken at Thu May 25 2017 07:48:42 GMT+0800 (CST) by ConfigServer:Balancer
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
No recent migrations
databases:
{ "_id" : "app", "primary" : "shard1", "partitioned" : false }
# 结果显示没有分区，记录插在shard1服务器
# 配置分片
# 允许分片的数据库
sh.enableSharding('app')
# 为用做shard key的字段建立索引，实际中可以用uuid字段
use app
db.demo.createIndex({id: 1})
{
"raw" : {
"shard1/10.0.70.104:27021,10.0.70.104:27022,10.0.70.104:27023" : {
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 1,
"numIndexesAfter" : 2,
"ok" : 1,
"$gleStats" : {
"lastOpTime" : {
"ts" : Timestamp(1495675335, 1),
"t" : NumberLong(1)
},
"electionId" : ObjectId("7fffffff0000000000000001")
}
}
},
"ok" : 1
}
# 允许分片的collection，指定shard key的字段
sh.shardCollection('app.demo', { id : 'hashed' })
{ "collectionsharded" : "app.demo", "ok" : 1 }
# 插入数据
for (var i = 1; i < 10000; i++) db.demo.insert({id: i, name: 'ken'})
WriteResult({ "nInserted" : 1 })
# 查看状态，可以看到db与collection的分片状态
sh.status()
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("59261bca37ceff575b36ef09")
}
shards:
{ "_id" : "shard1", "host" : "shard1/10.0.70.104:27021,10.0.70.104:27022,10.0.70.104:27023", "state" : 1 }
{ "_id" : "shard2", "host" : "shard2/10.0.70.105:27021,10.0.70.105:27022,10.0.70.105:27023", "state" : 1 }
active mongoses:
"3.4.4" : 1
autosplit:
Currently enabled: yes
balancer:
Currently enabled: yes
Currently running: no
Balancer lock taken at Thu May 25 2017 07:48:42 GMT+0800 (CST) by ConfigServer:Balancer
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
1 : Success
databases:
{ "_id" : "app", "primary" : "shard1", "partitioned" : true }
app.demo
shard key: { "id" : "hashed" }
unique: false
balancing: true
chunks:
shard1 2
shard2 2
{ "id" : { "$minKey" : 1 } } -->> { "id" : NumberLong("-4611686018427387902") } on : shard1 Timestamp(2, 2)
{ "id" : NumberLong("-4611686018427387902") } -->> { "id" : NumberLong(0) } on : shard1 Timestamp(2, 3)
{ "id" : NumberLong(0) } -->> { "id" : NumberLong("4611686018427387902") } on : shard2 Timestamp(2, 4)
{ "id" : NumberLong("4611686018427387902") } -->> { "id" : { "$maxKey" : 1 } } on : shard2 Timestamp(2, 5)
# shard1
db.demo.find().count()
4992
# shard2
db.demo.find().count()
5007
如果在允许colletion前demo有数据，执行以下命令时会报错。
sh.shardCollection('app.demo', { id : 'hashed' })
{
"proposedKey" : {
"id" : "hashed"
},
"curIndexes" : [
{
"v" : 2,
"key" : {
"_id" : 1
},
"name" : "_id_",
"ns" : "app.demo"
},
{
"v" : 2,
"key" : {
"id" : 1
},
"name" : "id_1",
"ns" : "app.demo"
}
],
"ok" : 0,
"errmsg" : "please create an index that starts with the shard key before sharding."
}
做法是将collection删除，重建索引。
chunksize默认是64M，如果分片过慢的话，可以适当调大，如512M。mongos的配置文件里。
Hashed Sharding
Ranged Sharding