Example AWS S3 Multipart Upload with aws-sdk for Node.js - Retries to upload failing parts

aws-multipartUpload.js

// Based on Glacier's example: http://docs.aws.amazon.com/AWSJavaScriptSDK/guide/examples.html#Amazon_Glacier__Multi-part_Upload
var fs = require('fs');
var AWS = require('aws-sdk');
AWS.config.loadFromPath('./aws-config.json');
var s3 = new AWS.S3();

// File
var fileName = '5.pdf';
var filePath = './' + fileName;
var fileKey = fileName;
var buffer = fs.readFileSync('./' + filePath);
// S3 Upload options
var bucket = 'loctest';

// Upload
var startTime = new Date();
var partNum = 0;
var partSize = 1024 * 1024 * 5; // Minimum 5MB per chunk (except the last part) http://docs.aws.amazon.com/AmazonS3/latest/API/mpUploadComplete.html
var numPartsLeft = Math.ceil(buffer.length / partSize);
var maxUploadTries = 3;
var multiPartParams = {
    Bucket: bucket,
    Key: fileKey,
    ContentType: 'application/pdf'
};
var multipartMap = {
    Parts: []
};

function completeMultipartUpload(s3, doneParams) {
  s3.completeMultipartUpload(doneParams, function(err, data) {
    if (err) {
      console.log("An error occurred while completing the multipart upload");
      console.log(err);
    } else {
      var delta = (new Date() - startTime) / 1000;
      console.log('Completed upload in', delta, 'seconds');
      console.log('Final upload data:', data);
    }
  });
}

function uploadPart(s3, multipart, partParams, tryNum) {
  var tryNum = tryNum || 1;
  s3.uploadPart(partParams, function(multiErr, mData) {
    if (multiErr){
      console.log('multiErr, upload part error:', multiErr);
      if (tryNum < maxUploadTries) {
        console.log('Retrying upload of part: #', partParams.PartNumber)
        uploadPart(s3, multipart, partParams, tryNum + 1);
      } else {
        console.log('Failed uploading part: #', partParams.PartNumber)
      }
      return;
    }
    multipartMap.Parts[this.request.params.PartNumber - 1] = {
      ETag: mData.ETag,
      PartNumber: Number(this.request.params.PartNumber)
    };
    console.log("Completed part", this.request.params.PartNumber);
    console.log('mData', mData);
    if (--numPartsLeft > 0) return; // complete only when all parts uploaded

    var doneParams = {
      Bucket: bucket,
      Key: fileKey,
      MultipartUpload: multipartMap,
      UploadId: multipart.UploadId
    };

    console.log("Completing upload...");
    completeMultipartUpload(s3, doneParams);
  });
}

// Multipart
console.log("Creating multipart upload for:", fileKey);
s3.createMultipartUpload(multiPartParams, function(mpErr, multipart){
  if (mpErr) { console.log('Error!', mpErr); return; }
  console.log("Got upload ID", multipart.UploadId);

  // Grab each partSize chunk and upload it as a part
  for (var rangeStart = 0; rangeStart < buffer.length; rangeStart += partSize) {
    partNum++;
    var end = Math.min(rangeStart + partSize, buffer.length),
        partParams = {
          Body: buffer.slice(rangeStart, end),
          Bucket: bucket,
          Key: fileKey,
          PartNumber: String(partNum),
          UploadId: multipart.UploadId
        };

    // Send a single part
    console.log('Uploading part: #', partParams.PartNumber, ', Range start:', rangeStart);
    uploadPart(s3, multipart, partParams);
  }
});

thanks for the input!

I created a similar script based on the async package including retries that might be a bit easier to use & understand for some ppl!

https://gist.github.com/magegu/ea94cca4a40a764af487

I am looking into your script, and wondering if there is a way i can resume broken uploads? For eg if my frontend app has uploaded PartNumber:2 and then encountered a broken internet connection, is it possible to resume the upload from where it got last uploaded i.e. partNumber2 instead of uploading from 0?

    /**
     * initiate a multipart upload and get an upload ID that must include in upload part request.
     * Each part must be at least 5 MB in size, except the last part.
     */
    async multiPart(options) {
        const { data, bucket, key } = options;
        const multiPartParams = {
            Bucket: bucket,
            Key: key
        };
        const multipart = await this._client.createMultipartUpload(multiPartParams).promise();
        const multipartMap = { Parts: [] };
        let partNum = 0;
        for (const d of data) {
            partNum += 1;
            const partParams = { ...multiPartParams, Body: d, PartNumber: String(partNum), UploadId: multipart.UploadId };
            const result = await this._client.uploadPart(partParams).promise();
            multipartMap.Parts[partNum - 1] = { ETag: result.ETag, PartNumber: Number(partNum) };
        }
        const doneParams = { ...multiPartParams, MultipartUpload: multipartMap, UploadId: multipart.UploadId };
        const result = await this._client.completeMultipartUpload(doneParams).promise();
        return result;
    }

Hi! Your solution looks very good, but i don't understand what kind of data i should use? I mean your data looks like it is an iterable object

@jotta008 Thank you !
Will this work with file size of 600 mb?