从Amazon Lambda发送发帖请求时出现问题

Question

I am trying to send http requests in POST from a amazon-lambda function after retrieving the messages from the amazon queue (sqs) to my API. The API integrate this messages in my database. for that I use Node.js with the system of promises but when I send a lot of messages in the queue the requests are not send and I do not understand why.

I tried several methods including with promiseAll but without success

const http = require('http');

var promises = [];

const options = {
    host: process.env.Host,
    path: process.env.Path,
    port: process.env.Port,
    method: process.env.Method
};

exports.handler = async (event, context) => {
    event.Records.forEach(record => {
        const {
            body
        } = record; // the messages from the bus

        promises.push(PromiseCreator(body));

        Promise.all(promises)
            .then(function(data) {})
            .catch(function(err) {
                return err
            });
    });
};



function PromiseCreator(body) {
    return new Promise((resolve, reject) => {
        const req = http.request(options, (res) => {
            resolve('succès');
        });

        req.on('error', (e) => {
            reject(Error(e));
        });


        // send the request
        req.write(body);
        req.end();

    });
}

I think the problem comes from the forEach, but i don't where i have to do the request.

Answer 1

I think the real problem is because your request function is resolving success immediately without listening for errors, which is useless. Your function named PromiseCreator should have a structure like the following example:

function PromiseCreator(body) {

   return new Promise((resolve, reject) => {

      const req = http.request(options, (res) => {
         if (res.statusCode !== 200) {
            reject("Connection error");
         }

         res.on('error', (error) => {
            reject(error);
         });
      });

      req.on('error', (e) => {
         reject(Error(e));
      });

      req.on("finish", () => {
         resolve("success");
      })

      // send the request
      req.write(body);
      req.end();

   });
}

Answer 2

You probably right!

Try put the promise.all outside of forEach .

And you can use await instead .then

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

             event.Records.forEach(record => {

                const { body }  = record; // the messages from the bus
                promises.push(PromiseCreator(body));

             });  

            try {
                 await Promise.all(promises);
            } catch(err) {
                 return err;
            }


    };