如何仅附加到 mongo 实例的主节点？

Question

这可能是我误解了 Mongo 的工作原理/新的 Go 开发 - 但我无法从 Go 连接到我的 mongo 实例。当我使用 Studio 3T 连接到我的 Mongo 实例时，我可以正常连接、浏览表格等。但是如果我尝试使用 Go 模块进行连接，它会抱怨无法找到所有节点。它是否必须能够访问所有节点？我认为副本集本身应该处理复制？

例如，我有这个 Go 代码：

    package main
    
    import (
        "context"
        "go.mongodb.org/mongo-driver/mongo"
        "go.mongodb.org/mongo-driver/mongo/options"
        "go.mongodb.org/mongo-driver/mongo/readpref"
        "log"
        "time"
    )
    
    func main() {
        log.Println("Hello World!")
    
        ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
        defer cancel()
    
        client, err := mongo.Connect(ctx, options.Client().ApplyURI("mongodb://MongoInsance:27017"))
        if err != nil {
            log.Fatal("Failed to connect to Mongo DB", err)
        }
    
        if err := client.Ping(ctx, readpref.Primary()); err != nil {
            log.Fatal("Not actually connected ", err)
        }
    
        res, err := client.ListDatabases(ctx, nil)
        if err != nil{
            log.Fatal("Failed to list databases")
        }
    
        for _, val := range res.Databases {
            log.Println(val.Name)
        }
        defer disconnect(client, &ctx)
    }
    
    func disconnect(client *mongo.Client, ctx *context.Context) {
        if err := client.Disconnect(*ctx); err != nil {
            panic(err)
        }
    }

但是我在运行上述代码时得到的响应给出了错误：

Not actually connected server selection error: context deadline exceeded, current topology: { Type: ReplicaSetNoPrimary, Servers: [{ Addr: mqtt-ingester-db-mast:27017, Type: Unknown, Last error: connection() error occured during connection handshake: dial tcp: lookup mqtt-ingester-db-mast: no such host }, { Addr: mqtt-ingester-db-rep1:27017, Type: Unknown, Last error: connection() error occured during connection handshake: dial tcp: lookup mqtt-ingester-db-rep1: no such host }, { Addr: mqtt-ingester-db-rep2:27017, Type: Unknown, Last error: connection() error occured during connection handshake: dial tcp: lookup mqtt-ingester-db-rep2: no such host }, ] }

我真的需要公开所有副本集吗？ 目前我有主节点和 2 个辅助节点在主机 MongoInstance 上的 docker 中运行，主节点连接到端口 27017：

docker-compose.yml

    services:
      ...
      mqtt-ingester-db-mast:
        container_name: mqtt-ingester-db-mast
        restart: always
        image: mongo:latest
        ports:
          - 27017:27017
        volumes:
          - 'mongo_main:/data/db'
        entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
      mqtt-ingester-db-rep1:
        container_name: mqtt-ingester-db-rep1
        restart: always
        image: mongo:latest
        expose:
          - 27017
        volumes:
          - 'mongo_rep1:/data/db'
        entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
      mqtt-ingester-db-rep2:
        container_name: mqtt-ingester-db-rep2
        restart: always
        image: mongo:latest
        expose:
          - 27017
        volumes:
          - 'mongo_rep2:/data/db'
        entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0" ]
      mqtt-ingester-setup:
        image: mongo:latest
        container_name: mqtt-ingester-setup
        links:
          - mqtt-ingester-db-mast:mqtt-ingester-db-mast
          - mqtt-ingester-db-rep1:mqtt-ingester-db-rep1
          - mqtt-ingester-db-rep2:mqtt-ingester-db-rep2
        depends_on:
          - mqtt-ingester-db-mast
          - mqtt-ingester-db-rep1
          - mqtt-ingester-db-rep2
        volumes:
          - ./mqtt-ingester:/scripts
        restart: "no"
        entrypoint: [ "bash", "/scripts/mqtt_ingester_setup.sh" ]
      mqtt-ingester-explorer:
        container_name: mqtt-ingester-explorer
        restart: always
        image: mongo-express:latest
        ports:
          - '8081:8081'
        depends_on:
          - mqtt-ingester-db-mast
        links:
          - mqtt-ingester-db-mast:mongo
      ...

Answer 1

我真的需要公开所有副本集吗？

是的。客户端需要查看副本集中的所有节点，以便在 master 宕机时进行故障转移。