Object Storage Service:Multipart upload

Background information

You can use the MultipartUpload method to upload a large object. In multipart upload, an object is split into multiple parts that are separately uploaded. If some parts fail to be uploaded, OSS records the upload progress. When you resume the upload, you need to upload only the parts that failed to be uploaded.

If the ConnectionTimeoutError error occurs when you use the MultipartUpload method, you need to fix the error. You can reduce the part size, extend the timeout period, or resend the request. You can also capture the ConnectionTimeoutError error and fix the error based on the cause. For more information, see Network connection timeout handling.

The following table describes the parameters that you can configure when you upload an object by using multipart upload.

Multipart upload example

The following sample code provides an example on how to use the multipartUpload method to perform multipart upload:

const OSS = require('ali-oss');
const path = require("path");

const client = new OSS({
  // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou. 
  region: 'yourregion',
  // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  authorizationV4: true,
  // Specify the name of the bucket. 
  bucket: 'yourbucketname',
});


const progress = (p, _checkpoint) => {
  // Record the upload progress of the object. 
  console.log(p); 
  // Record the checkpoint information about the multipart upload task. 
  console.log(_checkpoint); 
};

const headers = {  
  // Specify the storage class of the object. 
  'x-oss-storage-class': 'Standard', 
  // Specify tags for the object. You can specify multiple tags for the object. 
  'x-oss-tagging': 'Tag1=1&Tag2=2', 
  // Specify whether to overwite an existing object with the same name when the multipart upload task is initialized. In this example, this parameter is set to true, which indicates that an existing object with the same name as the object to upload is not overwritten. 
  'x-oss-forbid-overwrite': 'true'
}

// Start the multipart upload task. 
async function multipartUpload() {
  try {
    // Specify the full path of the object. Example: exampledir/exampleobject.txt. Then, specify the full path of the local file. Example: D:\\localpath\\examplefile.txt. Do not include the bucket name in the full path. 
    // By default, if you set this parameter to the name of a local file such as examplefile.txt without specifying the local path, the local file is uploaded from the local path of the project to which the sample program belongs. 
    const result = await client.multipartUpload('exampledir/exampleobject.txt', path.normalize('D:\\localpath\\examplefile.txt'), {
      progress,
      // headers,
      // Configure the meta parameter to specify metadata for the object. You can call the HeadObject operation to obtain the object metadata. 
      meta: {
        year: 2020,
        people: 'test',
      },
    });
    console.log(result);
    // Specify the full path of the object. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path. 
    const head = await client.head('exampledir/exampleobject.txt');
    console.log(head);
  } catch (e) {
    // Handle timeout exceptions. 
    if (e.code === 'ConnectionTimeoutError') {
      console.log('TimeoutError');
      // do ConnectionTimeoutError operation
    }
    console.log(e);
  }
}

multipartUpload();

The multipartUpload method in the preceding code sample contains the initMultipartUpload, uploadPart, and completeMultipartUpload operations. If you want to perform multipart upload step by step, call the preceding operations in sequence. For more information, see .initMultipartUpload, .uploadPart, and .completeMultipartUpload.

Cancel a multipart upload task

You can use the client.abortMultipartUpload method to cancel a multipart upload task. If you cancel a multipart upload task, you cannot use the upload ID to upload parts and the uploaded parts are deleted.

The following sample code provides an example on how to cancel a multipart upload task:

const OSS = require("ali-oss");

const client = new OSS({
  // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou. 
  region: "yourregion",
  // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  authorizationV4: true,
  // Specify the name of the bucket. 
  bucket: "yourbucketname",
});

async function abortMultipartUpload() {
  // Specify the full path of the object. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path. 
  const name = "exampledir/exampleobject.txt";
  // Specify the upload ID. You can obtain the upload ID from the response to the InitiateMultipartUpload operation. 
  const uploadId = "0004B999EF518A1FE585B0C9360D****";
  const result = await client.abortMultipartUpload(name, uploadId);
  console.log(result);
}

abortMultipartUpload();

List multipart upload tasks

You can use the client.listUploads method to list all ongoing multipart upload tasks, which are tasks that have been initiated but are not completed or canceled.

const OSS = require("ali-oss");

const client = new OSS({
  // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou. 
  region: "yourregion",
  // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  authorizationV4: true,
  // Specify the name of the bucket. 
  bucket: "yourbucketname",
});

async function listUploads(query = {}) {
  // You can configure the following parameters for query: prefix, marker, delimiter, upload-id-marker, and max-uploads. 
  const result = await client.listUploads(query);

  result.uploads.forEach((upload) => {
    // Specify the upload IDs of the multipart upload tasks. 
    console.log(upload.uploadId);
    // Combine all parts into a complete object and specify the full path of the object. 
    console.log(upload.name);
  });
}

const query = {
  // Specify the maximum number of multipart upload tasks to return for the current list operation. The default value and the maximum value of max-uploads are both 1000. 
  "max-uploads": 1000,
};
listUploads(query);

List uploaded parts

You can use the client.listParts method to list all parts that are uploaded by using the multipart upload task with the specified upload ID.

const OSS = require("ali-oss");

const client = new OSS({
  // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou. 
  region: "yourregion",
  // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  authorizationV4: true,
  // Specify the name of the bucket. 
  bucket: "yourbucketname",
});

async function listParts() {
  const query = {
    // Specify the maximum number of parts to return for the current list operation. The default value and the maximum value of max-parts are both 1000. 
    "max-parts": 1000,
  };
  let result;
  do { 
    result = await client.listParts(
      // Specify the full path of the object. Example: exampledir/exampleobject.txt. Do not include the bucket name in the full path. 
      "exampledir/exampleobject.txt",
      // Obtain the upload ID from the response to the InitiateMultipartUpload operation. You must obtain the upload ID before you call the CompleteMultipartUpload operation to complete the multipart upload task.
      "0004B999EF518A1FE585B0C9360D****",
      query
    );
    // Specify the starting position of the next list operation. Only parts with part numbers greater than the value of this parameter are listed. 
    query["part-number-marker"] = result.nextPartNumberMarker;
    result.parts.forEach((part) => {
      console.log(part.PartNumber);
      console.log(part.LastModified);
      console.log(part.ETag);
      console.log(part.Size);
    });
  } while (result.isTruncated === "true");
}

listParts();

References

• For the complete sample code for multipart upload, visit GitHub.

• The multipartUpload method that is used by OSS SDK for Node.js to perform multipart upload contains the following three API operations:

  • InitiateMultipartUpload

  • UploadPart

  • CompleteMultipartUpload

• For more information about the API operation that you can call to cancel a multipart upload task, see AbortMultipartUpload.

• For more information about the API operation that you can call to list uploaded parts, see ListParts.

• For more information about the API operation that you can call to list ongoing multipart upload tasks, see ListMultipartUploads. Ongoing multipart upload tasks are tasks that have been initiated but are not completed or canceled.