AWS Lambda函数同步问题

Question

我有一个AWS lambda函数，它的工作是侦听传入的SNS事件，从Secrets Manager检索RDS秘密，并使用npm上的mssql库使用3个sql查询执行sql事务。

let response;

const mssql = require("mssql");
const AWS = require("aws-sdk");
const uuidv4 = require("uuid/v4");

exports.handler = async (event, context) => {

    //console.log(JSON.stringify(event));
    var secret;
    var snsMessage = JSON.parse(event.Records[0].Sns.Message);
    console.log("getting secret");
    try {
        var data = await new AWS.SecretsManager().getSecretValue({ SecretId: process.env.DATABASE }).promise();
            console.log("got data");
        if ('SecretString' in data) {
            secret = data.SecretString;
            secret = JSON.parse(secret);
        }
        else {
            let buff = new Buffer(data.SecretBinary, 'base64');
            secret = buff.toString('ascii');
        }

        const config = {
            user: secret.username,
            password: secret.password,
            server: secret.host,
            database: "xxxxx",
            options: {
                encrypt: true
            }
        }
            console.log("creating config");
        try {
            //let pool = await mssql.ConnectionPool(config);
            let pool = await new mssql.ConnectionPool(config).connect();
            console.log("create connection pool");
            const transaction = await new mssql.Transaction(pool);
            console.log("create transaction");
            transaction.begin(async err => {
                if (err) console.log("Error" + err);
                console.log("getting request object");
                var request = await new mssql.Request(transaction);
                console.log("have request object");
                try {
                    console.log("Starting request 1");
                    await request
                        .input('owner', mssql.UniqueIdentifier, snsMessage.sub)
                        .input('email', mssql.VarChar(256), snsMessage.email)
                        .input('phone', mssql.VarChar(256), snsMessage.phone_number)
                        .input('address', mssql.VarChar(256), snsMessage.address)
                        .query(`insert into Users 
                                (PK_UUID, EMAIL, PHONE, FIRST_NAME, LAST_NAME, STREET_ADDRESS, CITY, STATE, STATUS, DATE_CREATED)
                                    VALUES
                                (@owner, @email, @phone, 'Test', 'Test', @address, 'xxx','xx','BASIC', Current_Timestamp)`)
                    console.log("Request 1 finished");
                    const newCompanyID = uuidv4();

                    console.log("Starting request 2");
                    await request
                        .input('owner', mssql.UniqueIdentifier, snsMessage.sub)
                        .input('companyID', mssql.UniqueIdentifier, newCompanyID)
                        .query(`insert into Company
                                (PK_UUID, STATUS, DATE_CREATED, OWNER)
                                    VALUES
                                (@companyID, 'INCOMPLETE', CURRENT_TIMESTAMP, @owner)`)

                    console.log("request 2 finished");
                    console.log("starting request 3");
                    await request
                        .input('owner', mssql.UniqueIdentifier, snsMessage.sub)
                        .input('companyID', mssql.UniqueIdentifier, newCompanyID)
                        .query(`insert into User_Roles
                                (PK_UUID, USERS, ROLES, COMPANIES, DATE_CREATED)
                                    VALUES
                                (newid(), @owner,'Company_Owner',@companyID, CURRENT_TIMESTAMP)`)

                    console.log("Request 3 finished");
                    console.log("Committing transactions");
                    await transaction.commit(err => {
                        if (err) console.log(err);
                        console.log("transactions committed");
                        response = {
                            'statusCode': 200,
                            'body': JSON.stringify({
                                message: 'hello world',

                            })
                        }
                        //return err;


                        return response
                    })
                }
                catch (err) {
                    console.log("error caught 1");
                    console.log(err);
                    await transaction.rollback(err => {
                        if (err) console.log(err);

                    })
                }

            })
        }
        catch (err) {
            console.log("error caught 2");
            if (err) console.log(err);
        }
    }
    catch (err) {
        console.log("error caught 3");
        console.log(err);
    }
console.log("Down Here")
};

10次中有1次它正确地将所有3个查询提交到数据库。每隔一次，console.log消息就会乱序，有时lambda函数会在事务连接打开时终止，导致连接被阻塞。这绝对是一个同步问题，但无法判断它是来自AWS Lambda、mssql库还是来自我自己的代码。

Answer 1

好吧，经过几个小时的绞尽脑汁，我终于明白了。最终引导我走上正确道路的答案可以在这里找到

如果有人在async/await函数中使用mssql事务处理这种情况，请参见下面的通用参考。基本上，所有的查询都包装在一个try/catch块中。如果这些查询中的任何一个失败，您就可以触发回滚。

const mssql = require('mssql')
const config = {
            user: "username",
            password: "password",
            server: "server",
            database: "database-name",
            options: {
                encrypt: true
            }

 let pool = await new mssql.ConnectionPool(config).connect();
 transaction = await new mssql.Transaction(pool);
 await new Promise(resolve => transaction.begin(resolve)); //This is the fix

 try{
   let request1 = new mssql.Request(transaction);
   let result1 = await request1.query('some query');

   let request2 = new mssql.Request(transaction);
   let result2 = await request2.query('some query');

   let request3 = new mssql.Request(transaction);
   let result3 = await request3.query('some query');

   await new Promise(resolve => transaction.commit(resolve));
 }
 catch(err)
 {
   await new Promise(resolve => transaction.rollback(resolve));
 }