CODEWITHSUNDEEP
javascripttypescriptamazon-web-servicesaws-lambdaaxios
Tristan Müller
Tristan Müller

Reputation: 412

AWS Lambda - Only getting answer after the second test trigger

I'm developing an AWS Lambda in TypeScript that uses Axios to get data from an API and that data will be filtered and be put into a dynamoDb.

The code looks as follows:

export {};
const axios = require("axios");
const AWS = require('aws-sdk');

exports.handler = async (event: any) => {
    const shuttleDB = new AWS.DynamoDB.DocumentClient();
    const startDate = "2021-08-16";
    const endDate = "2021-08-16";
    const startTime = "16:00:00";
    const endTime = "17:00:00";

    const response = await axios.post('URL', {
        data:{
            "von": startDate+"T"+startTime,
            "bis": endDate+"T"+endTime
        }}, {
            headers: {
            'x-rs-api-key': KEY
            }
        }
    );
    const params = response.data.data;
    const putPromise = params.map(async(elem: object) => {
        
        delete elem.feat1;
        delete elem.feat2;
        delete elem.feat3;
        delete elem.feat4;
        delete elem.feat5;
        
        const paramsDynamoDB = {
            TableName: String(process.env.TABLE_NAME),
            Item: elem
        }
        shuttleDB.put(paramsDynamoDB).promise();
    });
    await Promise.all(putPromise);
};

This all works kind of fine. If the test button gets pushed the first time, everything seems fine and is working. E.g. I received all the console.logs during developing but the data is not put into the db.

With the second try it is the same output but the data is successfully put into the Db.

Any ideas regarding this issue? How can I solve this problem and have the data put into the Db after the first try?

Thanks in advance!

Upvotes: 1

Views: 89

Answers (1)

andy mccullough
andy mccullough

Reputation: 9571

you need to return the promise from the db call -

return shuttleDB.put(paramsDynamoDB).promise();

also, Promise.all will complete early if any call fails (compared to Promise.allSettled), so it may be worth logging out any errors that may be happening too.

Better still, take a look at transactWrite - https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB/DocumentClient.html#transactWrite-property to ensure all or nothing gets written

Upvotes: 3

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