node.js – 在amazon lambda中,并行抛出多个缩略图大小异步抛出错误：Stream产生空缓冲区

我的代码在几秒内在本地运行正常,但在lambda云中,它不会并行运行,在调整第一个缩略图大小后抛出错误..如果我将其切换为串行而不是并行,则需要大约60连续运行的秒数.

为什么在lambda中并行运行调整大小代码会导致流产生空缓冲区错误.如何提高性能,以便我可以在几秒钟内创建尺寸,但在处理器成本方面仍然可以从lambda中获得良好的价值和效率？

// dependencies
var async = require('async');
var AWS = require('aws-sdk');
var gm = require('gm')
            .subClass({ imageMagick: true }); // Enable ImageMagick integration.
var util = require('util');

// constants
var SIZES = [100,320,640];

// get reference to S3 client 
var s3 = new AWs.S3();

exports.handler = function(event,context) {

    // Read options from the event.
    console.log("Reading options from event:\n",util.inspect(event,{depth: 5}));
    var srcBucket = event.Records[0].s3.bucket.name;
    var srcKey    = event.Records[0].s3.object.key;
    var dstBucket = srcBucket + "-resized";

    // Infer the image type.
    var typeMatch = srcKey.match(/\.([^.]*)$/);
    if (!typeMatch) {
        console.error('unable to infer image type for key ' + srcKey);
        return context.done();
    }
    var imageType = typeMatch[1];
    if (imageType != "jpg" && imageType != "png") {
        console.log('skipping non-image ' + srcKey);
        return context.done();
    }

    // Sanity check: validate that source and desTination are different buckets.
    if (srcBucket == dstBucket) {
        console.error("DesTination bucket must not match source bucket.");
        return context.done();
    }

    // Download the image from S3
    s3.getObject({
            Bucket: srcBucket,Key: srcKey
        },function(err,responsE){

            if (err)
                return console.error('unable to download image ' + err);

            var contentType = response.ContentType;

            var original =  gm(response.body);
            original.size(function(err,sizE){

                if(err)
                    return console.error(err);

                //transform,and upload to a different S3 bucket.
                async.each(SIZES,function (max_size,callBACk) {
                        resize_photo(size,max_size,imageType,original,srcKey,dstBucket,contentType,callBACk);
                    },function (err) {
                        if (err) {
                            console.error(
                                'Unable to resize ' + srcBucket +
                                ' due to an error: ' + err
                            );
                        } else {
                            console.log(
                                'successfully resized ' + srcBucket
                            );
                        }

                        context.done();
                    });
            });


        });



};

//wrap up variables into an options object
var resize_photo = function(size,donE) {

    var dstKey = max_size +  "_" + srcKey;


    // transform,and upload to a different S3 bucket.
    async.waterfall([

        function transform(next) {


            // Infer the scaling factor to avoid stretching the image unnaturally.
            var scalingFactor = Math.min(
                max_size / size.width,max_size / size.height
            );
            var width  = scalingFactor * size.width;
            var height = scalingFactor * size.height;


            // Transform the image buffer in memory.
            original.resize(width,height)
                .toBuffer(imageType,buffer) {

                    if (err) {
                        next(err);
                    } else {
                        next(null,buffer);
                    }
                });

        },function upload(data,next) {
            // Stream the transformed image to a different S3 bucket.
            s3.putObject({
                    Bucket: dstBucket,Key: dstKey,Body: data,ContentType: contentType
                },next);
            }
        ],function (err) {

            console.log('finished resizing ' + dstBucket + '/' + dstKey);

            if (err) {
                console.error(err)
                ;
            } else {
                console.log(
                    'successfully resized ' + dstKey
                );
            }

            done(err);
        }
    );
};