通过docker-compose搭建mongo的replica set高可用
前言
搭建一个mongo的集群,同时原来单机mongo的数据需要迁移到集群中。
处理思路:单机mongo的数据通过mongodump
备份,然后集群搭建起来了,在mongorestore
导入到集群中,实现数据的迁移。
备份数据
备份(mongodump)与恢复(mongorestore)
备份数据到本地
mongodump -h 192.168.56.201:37018 -u handle -p jimeng2017 -o /home/liz/Desktop/mongo-bei
数据恢复
新的集群安装完成之后,恢复数据到Primary节点,集群会自动同步到副本集中
mongorestore -h 192.168.56.201:37017 -u handle -p jimeng2017 /home/liz/Desktop/mongo-bei
注意:更换自己服务器上面的ip和mongo对应的账号密码
集群搭建
生成keyFile
- MongoDB使用keyfile认证,副本集中的每个mongod实例使用keyfile内容作为认证其他成员的共享密码。mongod实例只有拥有正确的keyfile才可以加入副本集。
- keyFile的内容必须是6到1024个字符的长度,且副本集所有成员的keyFile内容必须相同。
- 有一点要注意是的:在UNIX系统中,keyFile必须没有组权限或完全权限(也就是权限要设置成X00的形式)。Windows系统中,keyFile权限没有被检查。
- 可以使用任意方法生成keyFile。例如,如下操作使用openssl生成复杂的随机的1024个字符串。然后使用chmod修改文件权限,只给文件拥有者提供读权限。
# 400权限是要保证安全性,否则mongod启动会报错
openssl rand -base64 756 > mongodb.key
chmod 400 mongodb.key
每一个副本集成员都要使用相同的keyFile文件
创建yml文件
配置文件:
version: '3.3'
services:
mongodb1:
image: mongo:4.2.1
volumes:
- /data/mongo/data/mongo1:/data/db
- ./mongodb.key:/data/mongodb.key
user: root
environment:
- MONGO_INITDB_ROOT_USERNAME=handle
- MONGO_INITDB_ROOT_PASSWORD=jimeng2017
- MONGO_INITDB_DATABASE=handle
container_name: mongodb1
ports:
- 37017:27017
command: mongod --replSet mongos --keyFile /data/mongodb.key
restart: always
entrypoint:
- bash
- -c
- |
chmod 400 /data/mongodb.key
chown 999:999 /data/mongodb.key
exec docker-entrypoint.sh $$@
mongodb2:
image: mongo:4.2.1
volumes:
- /data/mongo/data/mongo2:/data/db
- ./mongodb.key:/data/mongodb.key
user: root
environment:
- MONGO_INITDB_ROOT_USERNAME=handle
- MONGO_INITDB_ROOT_PASSWORD=jimeng2017
- MONGO_INITDB_DATABASE=handle
container_name: mongodb2
ports:
- 37018:27017
command: mongod --replSet mongos --keyFile /data/mongodb.key
restart: always
entrypoint:
- bash
- -c
- |
chmod 400 /data/mongodb.key
chown 999:999 /data/mongodb.key
exec docker-entrypoint.sh $$@
mongodb3:
image: mongo:4.2.1
volumes:
- /data/mongo/data/mongo3:/data/db
- ./mongodb.key:/data/mongodb.key
user: root
environment:
- MONGO_INITDB_ROOT_USERNAME=handle
- MONGO_INITDB_ROOT_PASSWORD=jimeng2017
- MONGO_INITDB_DATABASE=handle
container_name: mongodb3
ports:
- 37019:27017
command: mongod --replSet mongos --keyFile /data/mongodb.key
restart: always
entrypoint:
- bash
- -c
- |
chmod 400 /data/mongodb.key
chown 999:999 /data/mongodb.key
exec docker-entrypoint.sh $$@
文件详解chown 999:999 /data/mongodb.key
999用户是容器中的mongod用户,通过chown修改文件用户权限mongod --replSet mongos --keyFile /data/mongodb.key
启动命令,--replSet mongos
以副本集形式启动并将副本集名字命名为 mongos ,--keyFile /data/mongodb.key
设置keyFile,用于副本集通信,文件通过 volumes 映射到容器内
然后启动
docker-compose -f docker-compose-set.yml up -d
初始化副本集
然后进去到第一个容器里面,初始化副本集
docker exec -it mongodb1 /bin/bash
登录
mongo -u 账号 -p 密码
登录成功可以查看状态
> rs.status()
{
"ok" : 0,"errmsg" : "no replset config has been received","code" : 94,"codeName" : "NotYetInitialized"
}
配置副本集
> rs.initiate({
... ... _id: "mongos",... ... members: [
... ... { _id : 0,host : "192.168.56.201:37017" },... ... { _id : 1,host : "192.168.56.201:37018" },... ... { _id : 2,host : "192.168.56.201:37019" }
... ... ]
... ... });
{ "ok" : 1 }
上面提示ok就是表示成功了,这时候会选举出Primary节点。重新通过rs.status()
查看状态就能看到了。
rs.status()
{
"set" : "mongos","date" : ISODate("2020-07-04T13:02:44.676Z"),"myState" : 1,"term" : NumberLong(1),"syncingTo" : "","syncSourceHost" : "","syncSourceId" : -1,"heartbeatIntervalMillis" : NumberLong(2000),"majorityVoteCount" : 2,"writeMajorityCount" : 2,"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1593867760,1),"t" : NumberLong(1)
},"lastCommittedWallTime" : ISODate("2020-07-04T13:02:40.809Z"),"readConcernMajorityOpTime" : {
"ts" : Timestamp(1593867760,"readConcernMajorityWallTime" : ISODate("2020-07-04T13:02:40.809Z"),"appliedOpTime" : {
"ts" : Timestamp(1593867760,"durableOpTime" : {
"ts" : Timestamp(1593867760,"lastAppliedWallTime" : ISODate("2020-07-04T13:02:40.809Z"),"lastDurableWallTime" : ISODate("2020-07-04T13:02:40.809Z")
},"lastStableRecoveryTimestamp" : Timestamp(1593867720,5),"lastStableCheckpointTimestamp" : Timestamp(1593867720,"electionCandidateMetrics" : {
"lastElectionReason" : "electionTimeout","lastElectionDate" : ISODate("2020-07-04T13:02:00.300Z"),"termAtElection" : NumberLong(1),"lastCommittedOpTimeAtElection" : {
"ts" : Timestamp(0,0),"t" : NumberLong(-1)
},"lastSeenOpTimeAtElection" : {
"ts" : Timestamp(1593867709,"numVotesNeeded" : 2,"priorityAtElection" : 1,"electionTimeoutMillis" : NumberLong(10000),"numCatchUpOps" : NumberLong(-29631936),"newTermStartDate" : ISODate("2020-07-04T13:02:00.787Z"),"wMajorityWriteAvailabilityDate" : ISODate("2020-07-04T13:02:01.528Z")
},"members" : [
{
"_id" : 0,"name" : "192.168.56.201:37017","ip" : "192.168.56.201","health" : 1,"state" : 1,"stateStr" : "PRIMARY","uptime" : 155,"optime" : {
"ts" : Timestamp(1593867760,"t" : NumberLong(1)
},"optimeDate" : ISODate("2020-07-04T13:02:40Z"),"infoMessage" : "could not find member to sync from","electionTime" : Timestamp(1593867720,"electionDate" : ISODate("2020-07-04T13:02:00Z"),"configVersion" : 1,"self" : true,"lastHeartbeatMessage" : ""
},{
"_id" : 1,"name" : "192.168.56.201:37018","state" : 2,"stateStr" : "SECONDARY","uptime" : 54,"optimeDurable" : {
"ts" : Timestamp(1593867760,"optimeDurableDate" : ISODate("2020-07-04T13:02:40Z"),"lastHeartbeat" : ISODate("2020-07-04T13:02:44.402Z"),"lastHeartbeatRecv" : ISODate("2020-07-04T13:02:43.511Z"),"pingMs" : NumberLong(0),"lastHeartbeatMessage" : "","syncingTo" : "192.168.56.201:37017","syncSourceHost" : "192.168.56.201:37017","syncSourceId" : 0,"infoMessage" : "","configVersion" : 1
},{
"_id" : 2,"name" : "192.168.56.201:37019","lastHeartbeatRecv" : ISODate("2020-07-04T13:02:43.533Z"),"configVersion" : 1
}
],"ok" : 1,"$clusterTime" : {
"clusterTime" : Timestamp(1593867760,"signature" : {
"hash" : BinData(0,"Zr91geLBqJM7xN3vVVMWnJYAexk="),"keyId" : NumberLong("6845609731550085123")
}
},"operationTime" : Timestamp(1593867760,1)
}
通过rs.status()
的输出我们就能分出那个是PRIMARY
节点了。
增加副本集
之前已经初始化了三个mongo,我们在原来的基础上再增加一个副本集。
首先编写docker-compose-set.yml
增加mongodb4
mongodb4:
image: mongo:4.2.1
volumes:
- /data/mongo/data/mongo4:/data/db
- ./mongodb.key:/data/mongodb.key
user: root
environment:
- MONGO_INITDB_ROOT_USERNAME=handle
- MONGO_INITDB_ROOT_PASSWORD=jimeng2017
- MONGO_INITDB_DATABASE=handle
container_name: mongodb4
ports:
- 37020:27017
command: mongod --replSet mongos --keyFile /data/mongodb.key
restart: always
entrypoint:
- bash
- -c
- |
chmod 400 /data/mongodb.key
chown 999:999 /data/mongodb.key
exec docker-entrypoint.sh $$@
启动
docker-compose -f docker-compose-set.yml up -d
然后进入到PRIMARY
,执行
> rs.add("192.168.56.201:37020")
{
"ok" : 1,"$clusterTime" : {
"clusterTime" : Timestamp(1593868399,"BZJ2tCwFE1NvE22/LwGzFTWy+1M="),"operationTime" : Timestamp(1593868399,1)
}
再次查看
> rs.status()
{
"set" : "mongos","date" : ISODate("2020-07-04T13:13:27.944Z"),"term" : NumberLong(3),"majorityVoteCount" : 3,"writeMajorityCount" : 3,"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1593868399,"t" : NumberLong(3)
},"lastCommittedWallTime" : ISODate("2020-07-04T13:13:19.243Z"),"readConcernMajorityOpTime" : {
"ts" : Timestamp(1593868399,"readConcernMajorityWallTime" : ISODate("2020-07-04T13:13:19.243Z"),"appliedOpTime" : {
"ts" : Timestamp(1593868399,"durableOpTime" : {
"ts" : Timestamp(1593868399,"lastAppliedWallTime" : ISODate("2020-07-04T13:13:19.243Z"),"lastDurableWallTime" : ISODate("2020-07-04T13:13:19.243Z")
},"lastStableRecoveryTimestamp" : Timestamp(1593868366,"lastStableCheckpointTimestamp" : Timestamp(1593868366,"lastElectionDate" : ISODate("2020-07-04T13:06:06.408Z"),"termAtElection" : NumberLong(3),"lastSeenOpTimeAtElection" : {
"ts" : Timestamp(1593867860,"numCatchUpOps" : NumberLong(37018),"newTermStartDate" : ISODate("2020-07-04T13:06:06.753Z"),"wMajorityWriteAvailabilityDate" : ISODate("2020-07-04T13:06:07.255Z")
},"uptime" : 452,"optime" : {
"ts" : Timestamp(1593868399,"t" : NumberLong(3)
},"optimeDurable" : {
"ts" : Timestamp(1593868399,"optimeDate" : ISODate("2020-07-04T13:13:19Z"),"optimeDurableDate" : ISODate("2020-07-04T13:13:19Z"),"lastHeartbeat" : ISODate("2020-07-04T13:13:27.642Z"),"lastHeartbeatRecv" : ISODate("2020-07-04T13:13:27.493Z"),"configVersion" : 2
},"lastHeartbeat" : ISODate("2020-07-04T13:13:27.622Z"),"pingMs" : NumberLong(13),"uptime" : 454,"electionTime" : Timestamp(1593867966,"electionDate" : ISODate("2020-07-04T13:06:06Z"),"configVersion" : 2,{
"_id" : 3,"name" : "192.168.56.201:37020","uptime" : 8,"lastHeartbeat" : ISODate("2020-07-04T13:13:27.418Z"),"lastHeartbeatRecv" : ISODate("2020-07-04T13:13:27.823Z"),"configVersion" : 2
}
],1)
}
可以看到最新的节点已经加进去了
将节点初始化也放到yml中
如果熟练了,我们可以将副本集的初始化也放到yml中完成
version: '3.3'
services:
mongodb1:
image: mongo:4.2.1
volumes:
- /data/mongo/data/mongo1:/data/db
- ./mongodb.key:/data/mongodb.key
user: root
environment:
- MONGO_INITDB_ROOT_USERNAME=handle
- MONGO_INITDB_ROOT_PASSWORD=jimeng2017
- MONGO_INITDB_DATABASE=handle
container_name: mongodb1
ports:
- 37017:27017
command: mongod --replSet mongos --keyFile /data/mongodb.key
restart: always
entrypoint:
- bash
- -c
- |
chmod 400 /data/mongodb.key
chown 999:999 /data/mongodb.key
exec docker-entrypoint.sh $$@
mongodb2:
image: mongo:4.2.1
volumes:
- /data/mongo/data/mongo2:/data/db
- ./mongodb.key:/data/mongodb.key
user: root
environment:
- MONGO_INITDB_ROOT_USERNAME=handle
- MONGO_INITDB_ROOT_PASSWORD=jimeng2017
- MONGO_INITDB_DATABASE=handle
container_name: mongodb2
ports:
- 37018:27017
command: mongod --replSet mongos --keyFile /data/mongodb.key
restart: always
entrypoint:
- bash
- -c
- |
chmod 400 /data/mongodb.key
chown 999:999 /data/mongodb.key
exec docker-entrypoint.sh $$@
mongodb3:
image: mongo:4.2.1
volumes:
- /data/mongo/data/mongo3:/data/db
- ./mongodb.key:/data/mongodb.key
user: root
environment:
- MONGO_INITDB_ROOT_USERNAME=handle
- MONGO_INITDB_ROOT_PASSWORD=jimeng2017
- MONGO_INITDB_DATABASE=handle
container_name: mongodb3
ports:
- 37019:27017
command: mongod --replSet mongos --keyFile /data/mongodb.key
restart: always
entrypoint:
- bash
- -c
- |
chmod 400 /data/mongodb.key
chown 999:999 /data/mongodb.key
exec docker-entrypoint.sh $$@
mongodb4:
image: mongo:4.2.1
volumes:
- /data/mongo/data/mongo4:/data/db
- ./mongodb.key:/data/mongodb.key
user: root
environment:
- MONGO_INITDB_ROOT_USERNAME=handle
- MONGO_INITDB_ROOT_PASSWORD=jimeng2017
- MONGO_INITDB_DATABASE=handle
container_name: mongodb4
ports:
- 37020:27017
command: mongod --replSet mongos --keyFile /data/mongodb.key
restart: always
entrypoint:
- bash
- -c
- |
chmod 400 /data/mongodb.key
chown 999:999 /data/mongodb.key
exec docker-entrypoint.sh $$@
mongodb-init:
image: mongo:4.2.1
depends_on:
- mongodb1
- mongodb2
- mongodb3
- mongodb4
restart: on-failure:5
command:
- mongo
- mongodb://handle:jimeng2017@192.168.56.201:37017/admin
- --eval
- 'rs.initiate({ _id: "mongos",members: [{_id:1,host:"192.168.56.201:37017"},{_id:2,host:"192.168.56.201:37018"},{_id:3,host:"192.168.56.201:37019"},{_id:4,host:"192.168.56.201:37020"}]})'
这样通过docker-compose up -d
就能完成镜像的构建和副本集的初始化
了解下Replica set
Replica set
,由一组Mongod实例(进程)组成,包含一个Primary节点和多个Secondary节点,Mongodb Driver
(客户端)的所有数据都写入Primary,Secondary从Primary同步写入的数据,通过这样的方式来保持复制集内所有成员存储相同的数据集,提供数据的高可用。
优点:
- 确保数据安全
- 高(24 * 7)数据可用性
- 灾难恢复
- 无需停机维护(例如备份,索引重建,压缩)
- 读取缩放(要读取的额外副本)
- 副本集对应用程序是透明的
复制在MongoDB中的工作方式
- MongoDB通过使用副本集来实现复制。 副本集是一组托管相同数据集的mongod实例。 在副本中,一个节点是接收所有写操作的主节点。 所有其他实例,例如第二实例,都将应用来自第一实例的操作,以便它们具有相同的数据集。 副本集只能有一个主节点。
- 副本集是一组两个或更多节点(通常至少需要3个节点)。
- 在副本集中,一个节点是主要节点,其余节点是次要节点。
- 所有数据从主节点复制到辅助节点。
- 在自动故障转移或维护时,将为主节点建立选举,并选举一个新的主节点。
- 恢复失败的节点后,它再次加入副本集并用作辅助节点。
下面就是工作的流程图
测试连接
使用go测试下是否能正常连接和读写数据。
show dbs;:查看数据库
> show dbs
admin 0.000GB
bs-cx 0.000GB
config 0.000GB
handle 0.001GB
handle-core4 0.019GB
local 0.020GB
stud 0.000GB
use stud;:切换到指定数据库,如果不存在该数据库就创建。
> use stud
switched to db stud
db;:显示当前所在数据库。
> db
stud
db.dropDatabase():删除当前数据库
> db.dropDatabase();
{ "ok" : 1 }
测试写入数据,使用的包https://github.com/mongodb/mongo-go-driver
package main
import (
"context"
"fmt"
"go.mongodb.org/mongo-driver/bson"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
"log"
)
type Student struct {
Name string
Age int
}
func main() {
uri := "mongodb://handle:jimeng2017@192.168.56.201:37017,192.168.56.201:37018,192.168.56.201:37019,192.168.56.201:37020/admin?replicaSet=mongos"
// 设置客户端连接配置
clientOptions := options.Client().ApplyURI(uri)
// 连接到MongoDB
client,err := mongo.Connect(context.TODO(),clientOptions)
if err != nil {
log.Fatal(err)
}
// 检查连接
err = client.Ping(context.TODO(),nil)
if err != nil {
log.Fatal(err)
}
fmt.Println("Connected to MongoDB!")
collection := client.Database("stud").Collection("student")
s1 := Student{"小红",12}
insertResult,err := collection.InsertOne(context.TODO(),s1)
if err != nil {
log.Fatal(err)
}
fmt.Println("Inserted a single document: ",insertResult.InsertedID)
var result Student
filter := bson.D{{"name","小红"}}
err = collection.FindOne(context.TODO(),filter).Decode(&result)
if err != nil {
log.Fatal(err)
}
fmt.Printf("Found a single document: %+v\n",result)
// 断开连接
err = client.Disconnect(context.TODO())
if err != nil {
log.Fatal(err)
}
fmt.Println("Connection to MongoDB closed.")
}
打印下输出
Connected to MongoDB!
Inserted a single document: ObjectID("5f00b6092aef651857151754")
Found a single document: {Name:小红 Age:12}
Connection to MongoDB closed.
成功连接上了