S3 Create Multipart Upload

Updated on 01 Jun 2023

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POSThttps://s3.<your-region>.backblazeb2.com/<your-bucket-name>/<your-key>?uploads

This action initiates a multipart upload and returns an uploadId. This uploadId is used to associate all of the parts in the specific multipart upload.

Encryption:
If encryption headers are omitted, Backblaze initiates the multipart upload with SSE-B2 when the bucket is enabled. All parts and the completed object inherit this choice.

AUTHORIZATION AWS Signature

This request is using AWS Signature from collection Backblaze B2 Cloud Storage S3 Compatible API.

Live Read

Backblaze B2 Live Read provides the ability to read data from a multipart object while that object is uploading.

To learn more about Live Read, click here.

Enabling Live Read

To enable the Live Read feature and allow data retrieval from a current multipart upload, use the x-backblaze-live-read-enabled HTTP header with a value set to true.

Part Size

You can also specify the part size when enabling Live Read by using the x-backblaze-live-read-part-size HTTP header. The part size (in bytes) has a minimum allowable size of 5 MB (5,000,000 bytes) and a maximum allowable size of 5 GiB (5,368,709,120 bytes).

The specified part size is used for all of the parts except the last part.

Note

When you make a Live Read-enabled S3 Get Object or S3 Head Object request with a byte range, the specified part size is used to determine which part numbers correspond to the requested byte range.

See "Live Read Error Codes" below for a complete list of Live Read-related errors.

HEADERS

x-backblaze-live-read-enabled

You must include this HTTP header with a value of TRUE(case-insensitive) to enable the Live Read feature.

Any value other than TRUE is treated as false.

x-backblaze-live-read-part-size

Use this optional header to specify the part size (in bytes) to be used to determine which part numbers correspond to the requested byte range.

The accepted part size byte range is 5 MB (5,000,000 bytes) to 5 GiB (5,368,709,120) bytes.

PARAMS

upload

Must be present for a multipart upload.

PATH VARIABLES

bucket	Required. The name of the bucket
key	Required. Key of the object to be written.

Example Request

curl --location --request POST 'https://s3.<your-region>.backblazeb2.com/my-bucket-name/object-1?uploads=null'

Example Response

200 OK

Body

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<InitiateMultipartUploadResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
    <Bucket>my-bucket-name</Bucket>
    <Key>object-1</Key>
    <UploadId>4_z6145af89f355ac2f74ed0c1b_f2025e1f1817e0030_d20220128_m233615_c004_v0402000_t0048</UploadId>
</InitiateMultipartUploadResult>

Headers

Cache-Control	max-age=0, no-cache, no-store
Content-Type	application/xml
Content-Length	348
x-amz-request-id	90e17e227a223955
x-amz-version-id	4_z6145af89f355ac2f74ed0c1b_f2025e1f1817e0030_d20220128_m233615_c004_v0402000_t0048
x-amz-id-2	aMa41BGZMOZMztjUfY9JmpzRnZLRjZmIQ
Date	Fri, 28 Jan 2022 23:14:48 GMT
Keep-Alive	timeout=5
Connection	keep-alive

Live Read Error Codes

Error code	Message	HTTP status code
InvalidArgument	Invalid Live Read part size provided in header `x-backblaze-live-read-part-size`.	400 Bad Request
InvalidArgument	Live Read part size in header `x-backblaze-live-read-part-size` is smaller than the minimum allowed size of 5000000 bytes.	400 Bad Request
InvalidArgument	Live Read part size in header `x-backblaze-live-read-part-size` is larger than the maximum allowed size of 5368709120 bytes.	400 Bad Request

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S3 Upload Part