Scenario

Errors can occur during data transfer between the client and server. To mitigate this, you can include the Content-MD5 value with the file when uploading it. Upon receiving the file, the server compares the received MD5 value with the one specified by the user. When the values match, the upload is successful, ensuring data consistency.

Verifying Data Consistency for an Uploaded Object

Calculate and record the MD5-encrypted binary array.
When uploading an object, set the request parameter Content-MD5 to the calculated value, as shown in the following example:

PUT /{Bucket}/{Key} HTTP/1.1
 
Host: xxx-ZOS native versionI (ZOS).esurfingcloud.com
 
X-Amz-Content-Sha256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
 
X-Amz-Date: 20220406T134209Z
 
Authorization: authorization string
 
ontent-MD5: ContentMD5
 
Body

Perform MD5 verification.
Upon receiving the file, the server compares the received MD5 value with the one specified by the user. When the values match, the upload is successful; otherwise, the upload fails.

Verifying Data Consistency for a Downloaded Object

When uploading an object, customize and record metadata for the object. Include the following field in the request parameters:
```
x-amz-meta-<…>: MD5
```
After downloading the object, extract the MD5 value from the customized metadata in the response. Calculate the MD5 value of the object and compare it with the extracted one to verify their consistency.

Zettabyte Object Storage

Data Consistency Checking