AWS Lambda “Process exited before completing request”

问题

I am trying to call a DynamoDB client method and get one item from the DynamoDB table. I am using AWS Lambda. However, I keep getting the message:

"Process exited before completing request."

I have increased the timeout just to make sure, but the processing time is less than the timeout. Any advice?

console.log('Loading event');
var AWS = require('aws-sdk');
var dynamodb = new AWS.DynamoDB({apiVersion: '2012-08-10'});

exports.handler = function(event, context) {
dynamodb.listTables(function(err, data) {
});

var params = {
    "TableName": "User",
     "Key":
        {"User Id"   : {"S":event.objectId}
    },
    "AttributesToGet"   : ["First Name","Last Name", "Latitude", "Longitude"],
    "ConsistentRead"    : true
  }


   dynamodb.getItem(params, function(response,result) {
    response.on('data', function(chunk){
    console.log(""+chunk);
    console.log("test1")
    context.done(result);
});
result.on('ready', function(data){
    console.log("test2")
    console.log("Error:" + data.error);
    console.log("ConsumedCapacityUnits:" + data.ConsumedCapacityUnits);
     context.done('Error',data);
    // ...
});
});
};

回答1:

The message "Process exited before completing request" means that the Javascript function exited before calling context.done (or context.succeed, etc.). Usually, this means that there is some error in your code.

I'm not a Javascript expert (at all) so there may be more elegant ways to find the error but my approach has been to put a bunch of console.log messages in my code, run it, and then look at the logs. I can usually zero in on the offending line and, if I look at it long enough, I can usually figure out my mistake.

I see you have some logging already. What are you seeing in the output?

回答2:

Take a look at your memory consumption (included in last log line). I got the same message when I assigned too little memory to my lambda function.

回答3:

I have used callback, instead of context.
More recent examples on aws website use callback instead of context.

To complete request, either of the below must be called:

callback(error);         // This is used when there is an error
// or
callback(null, data);    // This is used when there is a success
                         // 'data' will contain success result, like some JSON object

When lambda execution completes the request,
failing to call one of the above callbacks,
you will see below error:

"Process exited before completing request."

回答4:

Error in your code. Remove the last }); and don't use context it is there for backward compatibility, use callbacks on node.js 4.3 and 6.1 runtime.

来源：https://stackoverflow.com/questions/31627950/aws-lambda-process-exited-before-completing-request

标签

amazon-web-services

aws-lambda