javascript - MongoError : Topology is closed, 请连接(client.close 和 client.connect 问题)

Question

( Node :21140)UnhandledPromiseRejectionWarning:MongoError:拓扑已关闭，请连接

我认为这是一个与 CRUD 操作的每个函数中重复 client.connect 和 client.close 相关的错误，如下代码所示

//我认为集群 uri 没有问题，所以我没有发布它，因为它连接正常

const MongoClient = require("mongodb").MongoClient;

const uri = "mongodb+srv://username:pasword@some cluster"; 
//I think there is no issue with cluster uri so I didn't post that since it connects fine


const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });



async function AddnewService(service) {
    await client.connect()
    const database = client.db("twitch")
   const usr = await database.collection("recipes").find({ Title: service.Title }).toArray()
    if (usr.length >= 1) {
        await client.close()
        return { message: "Title already in use" }
    }
    else {
        const result = await database.collection("recipes").insertOne(service)
        await client.close()
        return { message: "Service Added to Database" }
    }
}

async function FetchAllserviceSearch(service) {
    await client.connect()
    const database = client.db("twitch")
    let recipesCursor = await database.collection("recipes").find({})
    while (await recipesCursor.hasNext()) {                       //make sure to put await on cursor .hasnext()
        let recipe = await recipesCursor.next()
        console.log(recipe)
    }
    await client.close()

    return { message: "User Added to Database" }
}


module.exports = {
    AddnewService,
    FetchAllserviceSearch
}

我尝试分配让 client.connect 和 client.close 仅​​被调用一次，但总是会导致新的错误。 我无法消除 module.export 因为我需要它们在其他文件中使用。

所以我需要一些帮助来解决这个问题，而不需要不必要的重复，因为 mongodbAtlas 会导致问题。

Answer 1

不要关闭你的数据库连接，你处于竞争状态，当两个请求到来时，一个将关闭另一个将打开。

client.close(); -----> remove

对所有请求使用相同的数据库连接。

const uri = "mongodb+srv://username:<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="7909180a0e160b1d391a150c0a0d1c0b4957101248090c571416171e161d1b57171c0d" rel="noreferrer noopener nofollow">[email protected]</a>/myFirstDatabase?retryWrites=true&w=majority";

let con;

async function connect(service) {
   if (con) return con; // return connection if already conncted
   const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
   con = client.connect()
   return con;
}


async function AddnewService(service) {
    const client = await connect();
    const database = client.db("twitch")
    const usr = await database.collection("recipes").find({ Title: service.Title }).toArray()
    if (usr.length >= 1) {
        // await client.close(); -----> remove
        return { message: "Title already in use" }
    }
    else {
        const result = await database.collection("recipes").insertOne(service)
        return { message: "Service Added to Database" }
    }
}

async function FetchAllserviceSearch(service) {
    const client = await connect();
    const database = client.db("twitch")
    let recipesCursor = await database.collection("recipes").find({})
    while (await recipesCursor.hasNext()) {                       //make sure to put await on cursor .hasnext()
        let recipe = await recipesCursor.next()
        console.log(recipe)
    }
    // await client.close(); -----> remove
    return { message: "User Added to Database" }
}


module.exports = {
    AddnewService,
    FetchAllserviceSearch
}