Initiate Multipart Upload¶
You can use this operation to obtain a globally unique upload ID.
This upload ID is used to associate all parts in the specific multipart upload. You can specify this upload ID in each of your subsequent requests such as Upload Part, Complete Multipart Upload, and List Parts.
The key of the object for which a multipart upload is intended can be the same as an existing object. You can initiate one or more multipart uploads for one object.
An Initiate Multipart Upload request can contain multiple headers such as x-amz-acl, x-amz-meta-*, Content-Type, and Content-Encoding. The headers are recorded in the metadata of parts uploaded for the specific multipart upload.
This operation makes server-side encryption available.
WORM¶
If a bucket has WORM enabled, you can configure object-level retention policies when initiating multipart uploads. You can specify the x-amz-object-lock-mode and x-amz-object-lock-retain-until-date headers when you initiate a multipart upload to protect the object assembled. If you do not specify these two headers but have configured a default bucket-level WORM policy, this default policy automatically applies to the object newly assembled. You can also configure or update a WORM retention policy after the object is assembled, see section Configuring WORM Retention for an Object.
Different from uploads with PUT and POST, a multipart upload only requires that the date specified in the x-amz-object-lock-retain-until-date header be no later than the initiation time, but does not have to be later than the completion time of the multipart upload. When the default bucket-level WORM policy is applied, the protection starts when the object parts are assembled and ends once the default bucket-level protection period expires. Before assembling the object parts uploaded, the multipart upload can be canceled and will not be affected by the WORM configuration.
Request Syntax¶
POST /ObjectName?uploads HTTP/1.1
User-Agent: agent
Host: bucketname.obs.example.com
Accept: */*
Date: date
Authorization: signatureValue
Request Parameters¶
This request uses a parameter to specify a multipart upload. Table 1 describes the parameters.
Parameter | Description | Remarks |
|---|---|---|
uploads | Indicates the ID of the multipart upload to be initiated. Type: String | Mandatory |
Request Headers¶
This request uses common headers. For details about common request headers, see section Common Request Headers.
This request also uses one optional header, as described in Table 2.
Header | Description | Remarks |
|---|---|---|
x-amz-storage-class | When creating an object, you can add this header in the request to set the storage class of the object. If you do not add this header, the object will use the default storage class of the bucket. Type: String Note: The storage class can be STANDARD (OBS Standard), STANDARD_IA (OBS Warm), or GLACIER (OBS Cold). Note that the three storage class values are case-sensitive. Example: x-amz-storage-class: STANDARD | Optional |
x-amz-website-redirect-location | If a bucket is configured as a website, redirects requests for this object to another object in the same bucket or to an external URL. OBS stores the value of this header in the object metadata. Type: String Default: None Constraint: The value must be prefixed by a slash (/), http://, or https://. The length of the value cannot exceed 2 K. | Optional |
x-amz-server-side-encryption | Indicates that SSE-KMS is used. Type: string Example: x-amz-server-side-encryption:aws:kms | No. This header is mandatory when SSE-KMS is used. |
x-amz-server-side-encryption-aws-kms-key-id | Indicates the master key ID. This header is used in SSE-KMS mode. If the customer does not provide the master key, the default master key will be used. Type: string Example: x-amz-server-side-encryption-aws-kms-key-id:arn:aws:kms:sichuan:domainiddomainiddomainiddoma0001:key/4f1cd4de-ab64-4807-920a-47fc42e7f0d0 | No |
x-amz-server-side-encryption-customer-algorithm | Indicates an encryption algorithm. The header is used in SSE-C mode. Type: string Example: x-amz-server-side-encryption-customer-algorithm:AES256 Constraints: This header must be used together with x-amz-server-side-encryption-customer-key and x-amz-server-side-encryption-customer-key-MD5. | No. This header is mandatory when SSE-C is used. |
x-amz-server-side-encryption-customer-key | Indicates a key used to encrypt objects. The header is used in SSE-C mode. Type: string Example: x-amz-server-side-encryption-customer-key:K7QkYpBkM5+hcs27fsNkUnNVaobncnLht/rCB2o/9Cw= Constraints: This header is a base64-encoded 256-bit or 512-bit key and must be used together with x-amz-server-side-encryption-customer-algorithm and x-amz-server-side-encryption-customer-key-MD5. | No. This header is mandatory when SSE-C is used. |
x-amz-server-side-encryption-customer-key-MD5 | Indicates the MD5 value of a key used to encrypt objects. The header is used in SSE-C mode. The MD5 value is used to check whether any error occurs during the transmission of the key. Type: string Example: x-amz-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ== Constraints: This header is a base64-encoded 128-bit MD5 value and must be used together with x-amz-server-side-encryption-customer-algorithm and x-amz-server-side-encryption-customer-key. | No. This header is mandatory when SSE-C is used. |
x-amz-security-token | Header field used to identify the request of a federated user. When the federal authentication function is enabled, users sending such requests are identified as federated users. Type: string | Optional. This parameter must be carried in the request sent by federated users. |
x-amz-object-lock-mode | WORM mode that will be applied to the object. Currently, only COMPLIANCE is supported. This header must be used together with x-amz-object-lock-retain-until-date. Type: string Example: x-amz-object-lock-mode:COMPLIANCE | No, but required when x-amz-object-lock-retain-until-date is present. |
x-amz-object-lock-retain-until-date | Indicates the expiration time of the Object Lock retention. The value must be a UTC time that complies with ISO 8601, for example, 2015-07-01T04:11:15Z. This header must be used together with x-amz-object-lock-mode. Type: string Example: x-amz-object-lock-retain-until-date:2015-07-01T04:11:15Z | No, but required when x-amz-object-lock-mode is present. |
For details about common request headers, see section Common Request Headers.
Request Elements¶
This request involves no elements.
Response Syntax¶
HTTP/1.1 status_code
Server: server
x-amz-id-2: id
x-amz-request-id: request id
x-reserved: amazon, aws and amazon web services are trademarks or registered trademarks of Amazon Technologies, Inc
Content-Type: type
Content-Length: length
Date: date
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<InitiateMultipartUploadResult xmlns="http://obs.example.com/doc/2015-06-30/">
<Bucket>BucketName</Bucket>
<Key>ObjectName</Key>
<UploadId>uploadID</UploadId>
</InitiateMultipartUploadResult>
Response Headers¶
This response uses common headers. For details about common response headers, see section Common Response Headers.
Header | Description |
|---|---|
x-amz-server-side-encryption | This header is included in a response if SSE-KMS is used. Type: string Example: x-amz-server-side-encryption:aws:kms |
x-amz-server-side-encryption-aws-kms-key-id | Indicates the master key ID. This header is included in a response if SSE-KMS is used. Example: x-amz-server-side-encryption-aws-kms-key-id:arn:aws:kms:sichuan:domainiddomainiddomainiddoma0001:key/4f1cd4de-ab64-4807-920a-47fc42e7f0d0 |
x-amz-server-side-encryption-customer-algorithm | Indicates an encryption algorithm. This header is included in a response if SSE-C is used. Type: string Example: x-amz-server-side-encryption-customer-algorithm:AES256 |
x-amz-server-side-encryption-customer-key-MD5 | Indicates the MD5 value of a key used to encrypt objects. This header is included in a response if SSE-C is used. Type: string Example: x-amz-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ== |
Response Elements¶
This response contains elements to indicate the upload ID and the key (name) of the object (bucket) for which the multipart upload was initiated. The returned information is used in the subsequent Upload Part and Complete Multipart Upload operations. Table 4 describes the elements.
Element | Description |
|---|---|
InitiateMultipartUploadResult | Indicates the container for the response. Type: XML |
Bucket | Indicates the name of the bucket for which the multipart upload was initiated. Type: String |
Key | Indicates the key of the object for which the multipart upload was initiated. Type: String |
UploadId | Indicates the ID for the initiated multipart upload. This ID is used for the subsequent Upload Part operation. Type: String |
Error Responses¶
If an AK or signature is invalid, OBS returns status code 403 Forbidden and error code AccessDenied.
If the requested bucket does not exist, OBS returns status code 404 Not Found and error code NoSuchBucket.
If the requester does not have WRITE permission for the requested bucket, OBS returns status code 403 Forbidden and error code AccessDenied.
For details about other error responses, see Table 1.
Sample Request¶
POST /objectkey?uploads HTTP/1.1
User-Agent: Jakarta Commons-HttpClient/3.1
Host: bucketname.obs.example.com
Accept: */*
Date: Mon, 1 Nov 2010 20:34:56 GMT
Authorization: AWS AKIAIOSFODNN7EXAMPLE:VGhpcyBtZXNzYWdlIHNpZ25lZGGieSRlbHZpbmc=
Sample Response¶
HTTP/1.1 200 OK
Server: OBS
x-amz-id-2: Weag1LuByRx9e6j5Onimru9pO4ZVKnJ2Qz7/C1NPcfTWAtRPfTaOFg==
x-amz-request-id: 996c76696e6727732072657175657374
x-reserved: amazon, aws and amazon web services are trademarks or registered trademarks of Amazon Technologies, Inc
Date: Mon, 1 Nov 2010 20:34:56 GMT
Content-Type: application/xml
Content-Length: 146
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<InitiateMultipartUploadResult xmlns="http://obs.example.com/doc/2015-06-30/">
<Bucket>bucket01</Bucket>
<Key>objectkey</Key>
<UploadId>DCD2FC98B4F70000013DF578ACA318E7</UploadId>
</InitiateMultipartUploadResult>