You can use the S3 HEAD Object request to retrieve metadata from an object without returning the object itself. If the object is stored in a Cloud Storage Pool, you can use HEAD Object to determine the object's transition state.
Using server-side encryption.
StorageGRID does not parse or interpret escaped UTF-8 characters in user-defined metadata. HEAD requests for an object with escaped UTF-8 characters in user-defined metadata do not return the x-amz-missing-meta header if the key name or value includes unprintable characters.
The following request header is not supported and returns XNotImplemented:
The response headers provide information about the state of an object as it is moved to a Cloud Storage Pool, optionally transitioned to a non-retrievable state, and restored.
State of object | Response to HEAD object |
---|---|
Object ingested into StorageGRID but not yet evaluated by ILM, or object stored in a traditional storage pool or using erasure coding | 200 OK (No special response header is returned.) |
Object in Cloud Storage Pool but not yet transitioned to a non-retrievable state |
200 OK x-amz-storage-class: GLACIER x-amz-restore: ongoing-request="false", expiry-date="Sat, 23 July 20 2030 00:00:00 GMT" Until the object is transitioned to a non-retrievable state, the value for expiry-date is set to some distant time in the future. The exact time of transition is not controlled by the StorageGRID system. |
Object has transitioned to non-retrievable state, but at least one copy also exists on the grid |
200 OK x-amz-storage-class: GLACIER x-amz-restore: ongoing-request="false", expiry-date="Sat, 23 July 20 2030 00:00:00 GMT" The value for expiry-date is set to some distant time in the future. Note: If the copy on the grid is not available (for example, a Storage Node is down), you must issue a POST Object restore request to restore the copy from the Cloud Storage Pool before you can successfully retrieve the object.
|
Object transitioned to a non-retrievable state, and no copy exists on the grid |
200 OK x-amz-storage-class: GLACIER |
Object in process of being restored from a non-retrievable state |
200 OK x-amz-storage-class: GLACIER x-amz-restore: ongoing-request="true" |
Object fully restored to the Cloud Storage Pool |
200 OK x-amz-storage-class: GLACIER x-amz-restore: ongoing-request="false", expiry-date="Sat, 23 July 20 2018 00:00:00 GMT" The expiry-date indicates when the object in the Cloud Storage Pool will be returned to a non-retrievable state. |
If you uploaded a multipart object or if StorageGRID split a large object into segments, StorageGRID determines whether the object is available in the Cloud Storage Pool by sampling a subset of the object's parts or segments. In some cases, a HEAD Object request might incorrectly return x-amz-restore: ongoing-request="false" when some parts of the object have already been transitioned to a non-retrievable state or when some parts of the object have not yet been restored.
If a
versionId
subresource is not specified, the operation
fetches the most recent version of the object in a versioned
bucket. If the current version of the object is a delete marker,
a
Not Found
status is returned with the
x-amz-delete-marker
response header set to
true.