Restoring a Cold Object¶

Function¶

To obtain the content of an object in the Cold storage class, you need to restore the object first and then you can download it. After an object is restored, a copy of the object is saved in the Standard storage class. By doing so, the object in the Cold storage class and its copy in the Standard storage class co-exist in the bucket. The copy will be automatically deleted once its retention period expires.

This API is used to restore Cold objects in a specified bucket.

Restrictions¶

To restore a Cold object, you must be the bucket owner or have the required permission (obs:object:RestoreObject in IAM or RestoreObject in a bucket policy.)
To prolong the validity period of the Cold data restored, you can repeatedly restore the data, but you will be billed for each restore. After a second restore, the validity period of Standard object copies will be prolonged, and you need to pay for storing these copies during the prolonged period.

Method¶

func (obsClient ObsClient) RestoreObject(input *RestoreObjectInput) (output *BaseModel, err error)

Request Parameters¶

**Table 1** List of request parameters¶
Parameter	Type	Mandatory (Yes/No)	Description
input	*RestoreObjectInput	Yes	Explanation: Input parameters for restoring a Cold object. For details, see Table 2.

**Table 2** RestoreObjectInput¶
Parameter	Type	Mandatory (Yes/No)	Description
Bucket	string	Yes	Explanation: Bucket name Restrictions: A bucket name must be unique across all accounts and regions. A bucket name: Must be 3 to 63 characters long and start with a digit or letter. Lowercase letters, digits, hyphens (-), and periods (.) are allowed. Cannot be formatted as an IP address. Cannot start or end with a hyphen (-) or period (.). Cannot contain two consecutive periods (..), for example, my..bucket. Cannot contain a period (.) and a hyphen (-) adjacent to each other, for example, my-.bucket or my.-bucket. If you repeatedly create buckets of the same name in the same region, no error will be reported and the bucket attributes comply with those set in the first creation request. Default value: None
Key	string	Yes	Explanation: Object name. An object is uniquely identified by an object name in a bucket. An object name is a complete path that does not contain the bucket name. Value range: The value must contain 1 to 1,024 characters. Default value: None
VersionId	string	No	Explanation: Version ID of the Cold object to be restored Default value: None. If this parameter is left blank, the latest version of the object is specified.
Days	int	Yes	Explanation: After an object is restored, a Standard copy of it is generated. This parameter specifies how long the Standard copy can be retained, that is, the validity period of the restored object. Value range: The value ranges from 1 to 30, in days. Default value: None
Tier	RestoreTierType	No	Explanation: Retrieval speed tiers. You can select a suitable tier based on your requirements for retrieval speed. Value range: For details, see Table 3. Default value: Standard

**Table 3** RestoreTierType¶
Constant	Default Value	Description
RestoreTierExpedited	Expedited	Objects can be quickly restored from Cold storage within 1 to 5 minutes.
RestoreTierStandard	Standard	Objects can be restored from Cold storage within 3 to 5 hours.

Responses¶

**Table 4** List of returned results¶
Parameter	Type	Description
output	*BaseModel	Explanation: Returned results. For details, see Table 5.
err	error	Explanation: Error messages returned by the API

**Table 5** BaseModel¶
Parameter	Type	Description
StatusCode	int	Explanation: HTTP status code Value range: A status code is a group of digits that can be 2xx (indicating successes) or 4xx or 5xx (indicating errors). It indicates the status of a response. Default value: None
RequestId	string	Explanation: Request ID returned by the OBS server Default value: None
ResponseHeaders	map[string][]string	Explanation: HTTP response headers Default value: None

Code Examples¶

This example restores the Cold object example/objectname in bucket examplebucket.

package main
import (
    "fmt"
    "os"
    "obs-sdk-go/obs"
)
func main() {
    //Obtain an AK/SK pair using environment variables or import an AK/SK pair in other ways. Using hard coding may result in leakage.
    //Obtain an AK/SK pair on the management console.
    ak := os.Getenv("AccessKeyID")
    sk := os.Getenv("SecretAccessKey")
    // (Optional) If you use a temporary AK/SK pair and a security token to access OBS, you are advised not to use hard coding to reduce leakage risks. You can obtain an AK/SK pair using environment variables or import an AK/SK pair in other ways.
    // securityToken := os.Getenv("SecurityToken")
    // Enter the endpoint of the region where the bucket locates.
    endPoint := "https://your-endpoint"
    // Create an obsClient instance.
    // If you use a temporary AK/SK pair and a security token to access OBS, use the obs.WithSecurityToken method to specify a security token when creating an instance.
    obsClient, err := obs.New(ak, sk, endPoint/*, obs.WithSecurityToken(securityToken)*/)
    if err != nil {
        fmt.Printf("Create obsClient error, errMsg: %s", err.Error())
    }
    input := &obs.RestoreObjectInput{}
    // Specify a bucket name.
    input.Bucket = "examplebucket"
    // Specify the object (example/objectname in this example).
    input.Key = "example/objectname"
    // Specify the version ID of the object to be restored.
    input.VersionId = "G001117FCE89978B0000401205D5DC9A"
    // Specify how long the restored object will be retained, in days. 1 is used as an example, which can be any value from 1 to 30.
    input.Days = 1
    // Specify the restore speed (obs.RestoreTierExpedited as an example). By default, the object is restored at a standard speed.
    input.Tier = obs.RestoreTierExpedited
    // Restore the Cold object.
    output, err := obsClient.RestoreObject(input)
    if err == nil {
        fmt.Printf("Restore object(%s) under the bucket(%s) successful!\n", input.Key, input.Bucket)
        fmt.Printf("RequestId:%s\n", output.RequestId)
        return
    }
    fmt.Printf("Restore object(%s) under the bucket(%s) fail!\n", input.Key, input.Bucket)
    if obsError, ok := err.(obs.ObsError); ok {
        fmt.Println("An ObsError was found, which means your request sent to OBS was rejected with an error response.")
        fmt.Println(obsError.Error())
    } else {
        fmt.Println("An Exception was found, which means the client encountered an internal problem when attempting to communicate with OBS, for example, the client was unable to access the network.")
        fmt.Println(err)
    }
}

Note

The object specified in ObsClient.RestoreObject must be in the Cold storage class. Otherwise, an error will be reported.
RestoreObjectInput.Days is used to specify how long (1 to 30 days) the restored object will be retained and RestoreObjectInput.Tier is used to specify how fast the object will be restored.

last updated: 2025-08-28 14:06 UTC - commit: 39882e2dd8910deda6bee60c54bef141ea2cac76