通過docker-compose搭建mongo的replica set高可用
前言
搭建一個mongo的集群，同時原來單機mongo的數據需要遷移到集群中。
處理思路：單機mongo的數據通過mongodump備份，然后集群搭建起來了，在mongorestore導入到集群中，實現數據的遷移。
備份數據
備份(mongodump)與恢復(mongorestore)
備份數據到本地
mongodump -h 192.168.56.201:37018 -u handle -p jimeng2017 -o /home/liz/Desktop/mongo-bei
數據恢復
新的集群安裝完成之后，恢復數據到Primary節點，集群會自動同步到副本集中
mongorestore -h 192.168.56.201:37017 -u handle -p jimeng2017 /home/liz/Desktop/mongo-bei
注意：更換自己服務器上面的ip和mongo對應的賬號密碼
集群搭建
生成keyFile
- MongoDB使用keyfile認證，副本集中的每個mongod實例使用keyfile內容作為認證其他成員的共享密碼。mongod實例只有擁有正確的keyfile才可以加入副本集。
- keyFile的內容必須是6到1024個字符的長度，且副本集所有成員的keyFile內容必須相同。
- 有一點要注意是的：在UNIX系統中，keyFile必須沒有組權限或完全權限（也就是權限要設置成X00的形式）。Windows系統中，keyFile權限沒有被檢查。
- 可以使用任意方法生成keyFile。例如，如下操作使用openssl生成復雜的隨機的1024個字符串。然后使用chmod修改文件權限，只給文件擁有者提供讀權限。
# 400權限是要保證安全性，否則mongod啟動會報錯
openssl rand -base64 756 > mongodb.key
chmod 400 mongodb.key
每一個副本集成員都要使用相同的keyFile文件
創建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 $$@
文件詳解
chown 999:999 /data/mongodb.key 999用戶是容器中的mongod用戶，通過chown修改文件用戶權限
mongod --replSet mongos --keyFile /data/mongodb.key 啟動命令，--replSet mongos 以副本集形式啟動並將副本集名字命名為 mongos ，--keyFile /data/mongodb.key 設置keyFile，用於副本集通信，文件通過 volumes 映射到容器內
然后啟動
docker-compose -f docker-compose-set.yml up -d
初始化副本集
然后進去到第一個容器里面，初始化副本集
docker exec -it mongodb1 /bin/bash
登錄
mongo -u 賬號 -p 密碼
登錄成功可以查看狀態
> 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，這時候會選舉出Primary節點。重新通過rs.status()查看狀態就能看到了。
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, 1),
"t" : NumberLong(1)
},
"readConcernMajorityWallTime" : ISODate("2020-07-04T13:02:40.809Z"),
"appliedOpTime" : {
"ts" : Timestamp(1593867760, 1),
"t" : NumberLong(1)
},
"durableOpTime" : {
"ts" : Timestamp(1593867760, 1),
"t" : NumberLong(1)
},
"lastAppliedWallTime" : ISODate("2020-07-04T13:02:40.809Z"),
"lastDurableWallTime" : ISODate("2020-07-04T13:02:40.809Z")
},
"lastStableRecoveryTimestamp" : Timestamp(1593867720, 5),
"lastStableCheckpointTimestamp" : Timestamp(1593867720, 5),
"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, 1),
"t" : NumberLong(-1)
},
"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, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2020-07-04T13:02:40Z"),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "could not find member to sync from",
"electionTime" : Timestamp(1593867720, 1),
"electionDate" : ISODate("2020-07-04T13:02:00Z"),
"configVersion" : 1,
"self" : true,
"lastHeartbeatMessage" : ""
},
{
"_id" : 1,
"name" : "192.168.56.201:37018",
"ip" : "192.168.56.201",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 54,
"optime" : {
"ts" : Timestamp(1593867760, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1593867760, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2020-07-04T13:02:40Z"),
"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",
"ip" : "192.168.56.201",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 54,
"optime" : {
"ts" : Timestamp(1593867760, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1593867760, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2020-07-04T13:02:40Z"),
"optimeDurableDate" : ISODate("2020-07-04T13:02:40Z"),
"lastHeartbeat" : ISODate("2020-07-04T13:02:44.402Z"),
"lastHeartbeatRecv" : ISODate("2020-07-04T13:02:43.533Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.56.201:37017",
"syncSourceHost" : "192.168.56.201:37017",
"syncSourceId" : 0,
"infoMessage" : "",
"configVersion" : 1
}
],
"ok" : 1,
"$clusterTime" : {
"clusterTime" : Timestamp(1593867760, 1),
"signature" : {
"hash" : BinData(0,"Zr91geLBqJM7xN3vVVMWnJYAexk="),
"keyId" : NumberLong("6845609731550085123")
}
},
"operationTime" : Timestamp(1593867760, 1)
}
通過rs.status()的輸出我們就能分出那個是PRIMARY節點了。
增加副本集
之前已經初始化了三個mongo，我們在原來的基礎上再增加一個副本集。
首先編寫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 $$@
啟動
docker-compose -f docker-compose-set.yml up -d
然后進入到PRIMARY,執行
> rs.add("192.168.56.201:37020")
{
"ok" : 1,
"$clusterTime" : {
"clusterTime" : Timestamp(1593868399, 1),
"signature" : {
"hash" : BinData(0,"BZJ2tCwFE1NvE22/LwGzFTWy+1M="),
"keyId" : NumberLong("6845609731550085123")
}
},
"operationTime" : Timestamp(1593868399, 1)
}
再次查看
> rs.status()
{
"set" : "mongos",
"date" : ISODate("2020-07-04T13:13:27.944Z"),
"myState" : 1,
"term" : NumberLong(3),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"heartbeatIntervalMillis" : NumberLong(2000),
"majorityVoteCount" : 3,
"writeMajorityCount" : 3,
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"lastCommittedWallTime" : ISODate("2020-07-04T13:13:19.243Z"),
"readConcernMajorityOpTime" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"readConcernMajorityWallTime" : ISODate("2020-07-04T13:13:19.243Z"),
"appliedOpTime" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"durableOpTime" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"lastAppliedWallTime" : ISODate("2020-07-04T13:13:19.243Z"),
"lastDurableWallTime" : ISODate("2020-07-04T13:13:19.243Z")
},
"lastStableRecoveryTimestamp" : Timestamp(1593868366, 1),
"lastStableCheckpointTimestamp" : Timestamp(1593868366, 1),
"electionCandidateMetrics" : {
"lastElectionReason" : "electionTimeout",
"lastElectionDate" : ISODate("2020-07-04T13:06:06.408Z"),
"termAtElection" : NumberLong(3),
"lastCommittedOpTimeAtElection" : {
"ts" : Timestamp(0, 0),
"t" : NumberLong(-1)
},
"lastSeenOpTimeAtElection" : {
"ts" : Timestamp(1593867860, 1),
"t" : NumberLong(1)
},
"numVotesNeeded" : 2,
"priorityAtElection" : 1,
"electionTimeoutMillis" : NumberLong(10000),
"numCatchUpOps" : NumberLong(37018),
"newTermStartDate" : ISODate("2020-07-04T13:06:06.753Z"),
"wMajorityWriteAvailabilityDate" : ISODate("2020-07-04T13:06:07.255Z")
},
"members" : [
{
"_id" : 0,
"name" : "192.168.56.201:37017",
"ip" : "192.168.56.201",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 452,
"optime" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"optimeDurable" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"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"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "",
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "",
"configVersion" : 2
},
{
"_id" : 1,
"name" : "192.168.56.201:37018",
"ip" : "192.168.56.201",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 452,
"optime" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"optimeDurable" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"optimeDate" : ISODate("2020-07-04T13:13:19Z"),
"optimeDurableDate" : ISODate("2020-07-04T13:13:19Z"),
"lastHeartbeat" : ISODate("2020-07-04T13:13:27.622Z"),
"lastHeartbeatRecv" : ISODate("2020-07-04T13:13:27.493Z"),
"pingMs" : NumberLong(13),
"lastHeartbeatMessage" : "",
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "",
"configVersion" : 2
},
{
"_id" : 2,
"name" : "192.168.56.201:37019",
"ip" : "192.168.56.201",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 454,
"optime" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"optimeDate" : ISODate("2020-07-04T13:13:19Z"),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "",
"electionTime" : Timestamp(1593867966, 1),
"electionDate" : ISODate("2020-07-04T13:06:06Z"),
"configVersion" : 2,
"self" : true,
"lastHeartbeatMessage" : ""
},
{
"_id" : 3,
"name" : "192.168.56.201:37020",
"ip" : "192.168.56.201",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 8,
"optime" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"optimeDurable" : {
"ts" : Timestamp(1593868399, 1),
"t" : NumberLong(3)
},
"optimeDate" : ISODate("2020-07-04T13:13:19Z"),
"optimeDurableDate" : ISODate("2020-07-04T13:13:19Z"),
"lastHeartbeat" : ISODate("2020-07-04T13:13:27.418Z"),
"lastHeartbeatRecv" : ISODate("2020-07-04T13:13:27.823Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "",
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "",
"configVersion" : 2
}
],
"ok" : 1,
"$clusterTime" : {
"clusterTime" : Timestamp(1593868399, 1),
"signature" : {
"hash" : BinData(0,"BZJ2tCwFE1NvE22/LwGzFTWy+1M="),
"keyId" : NumberLong("6845609731550085123")
}
},
"operationTime" : Timestamp(1593868399, 1)
}
可以看到最新的節點已經加進去了
將節點初始化也放到yml中
如果熟練了，我們可以將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"}]})'
這樣通過docker-compose up -d就能完成鏡像的構建和副本集的初始化
了解下Replica set
Replica set，由一組Mongod實例（進程）組成，包含一個Primary節點和多個Secondary節點,Mongodb Driver（客戶端）的所有數據都寫入Primary，Secondary從Primary同步寫入的數據,通過這樣的方式來保持復制集內所有成員存儲相同的數據集，提供數據的高可用。
優點：
- 確保數據安全
- 高（24 * 7）數據可用性
- 災難恢復
- 無需停機維護（例如備份，索引重建，壓縮）
- 讀取縮放（要讀取的額外副本）
- 副本集對應用程序是透明的
復制在MongoDB中的工作方式
- MongoDB通過使用副本集來實現復制。 副本集是一組托管相同數據集的mongod實例。 在副本中，一個節點是接收所有寫操作的主節點。 所有其他實例，例如第二實例，都將應用來自第一實例的操作，以便它們具有相同的數據集。 副本集只能有一個主節點。
- 副本集是一組兩個或更多節點（通常至少需要3個節點）。
- 在副本集中，一個節點是主要節點，其余節點是次要節點。
- 所有數據從主節點復制到輔助節點。
- 在自動故障轉移或維護時，將為主節點建立選舉，並選舉一個新的主節點。
- 恢復失敗的節點后，它再次加入副本集並用作輔助節點。
下面就是工作的流程圖
測試連接
使用go測試下是否能正常連接和讀寫數據。
show dbs;：查看數據庫
> 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;：切換到指定數據庫，如果不存在該數據庫就創建。
> use stud
switched to db stud
db;：顯示當前所在數據庫。
> db
stud
db.dropDatabase()：刪除當前數據庫
> db.dropDatabase();
{ "ok" : 1 }
測試寫入數據，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"
// 設置客戶端連接配置
clientOptions := options.Client().ApplyURI(uri)
// 連接到MongoDB
client, err := mongo.Connect(context.TODO(), clientOptions)
if err != nil {
log.Fatal(err)
}
// 檢查連接
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{"小紅", 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", "小紅"}}
err = collection.FindOne(context.TODO(), filter).Decode(&result)
if err != nil {
log.Fatal(err)
}
fmt.Printf("Found a single document: %+v\n", result)
// 斷開連接
err = client.Disconnect(context.TODO())
if err != nil {
log.Fatal(err)
}
fmt.Println("Connection to MongoDB closed.")
}
打印下輸出
Connected to MongoDB!
Inserted a single document: ObjectID("5f00b6092aef651857151754")
Found a single document: {Name:小紅 Age:12}
Connection to MongoDB closed.
成功連接上了