AWS lambda - cannot connect to RDS database, only locally

Question

I am trying to connect to a RDS instance from a lambda. I made and tested the lambda locally, it worked perfectly. However, when I deploy to AWS the code is normally executed until the part where the connection to the bank is made. From this, not even log messages appear.

Note: I am using context.callbackWaitsForEmptyEventLoop = false;

Note: I am not using VPC in lambda.

Obs3: I have older planes that work normal, only the new ones are with this problem, even if the configurations are the same.

This is the relevant part of the code:

if (body && body.modality_id) {

            console.log('Just debugging...')

            DB.query("call sp_create_transaction (?)",[body.modality_id])
                .then(results => {
                    if (results[0][0]) {
                        if (results[0][0].Error) {
                            helper.body = { 'message': results[0][0].Error };
                            console.log('Error:' + results[0][0].Error);
                        }
                        else {
                            helper.statusCode = 200;
                            helper.body = results[0];
                            console.log(helper.body);
                            console.log('EXECUTION SUCCESS:');
                        }
                    }
                    else {
                        helper.statusCode = 401;
                        helper.body = { 'message': 'Falha ao buscar taxas.' };
                        console.log('Error: Rates not found.');
                    }
                    callback(null, helper.response);
                })
                .catch(err => {
                    helper.statusCode = 500;
                    helper.body = { 'message': 'Por favor, informa ao time de suporte técnico o código DAN-54.' };
                    console.log('Error: DAN-54');
                    console.log(err);
                    callback(null, helper.response);
                });
        }

Here is the log output:

START RequestId: fb134979-7d0e-4fa3-b7c8-4192f4765ea8 Version: $LATEST
2019-05-28T23:47:26.609Z fb134979-7d0e-4fa3-b7c8-4192f4765ea8 INFO Just debugging...
END RequestId: fb134979-7d0e-4fa3-b7c8-4192f4765ea8
REPORT RequestId: fb134979-7d0e-4fa3-b7c8-4192f4765ea8 Duration: 1273.33 ms Billed Duration: 1300 ms Memory Size: 128 MB Max Memory Used: 79 MB 

Answer 1

Hard to say, but since the execution duration seems small for proc execution, my hypothesis is that the lambda is returning before the asynchronous execution of DB.query(), so you don’t see any more output. To confirm you can increase the timeout and if so, use async/await or the Promises API to wait for the result before invoking the return callback.

Answer 2

I implemented some lambda connecting on the RDS used the serverless framework That’s what it’s all about. To be able to connect in RDS your lamnda has to have access to VPC, the subnet that the bank finds more permissions in RDS itself

You have to configure on the network part of the lambda page