HTTP status code 424-Object Storage Service(OSS)-阿里云帮助中心

OSS returns HTTP status code 424 when a mirroring-based back-to-origin request fails. All errors under this status code share the error code MirrorFailed.

The following table lists each error message, its cause, and the steps to resolve it.

MirrorFailed errors

Error message	Cause	Resolution
`Mirroring failed, please check your mirror configuration`	The back-to-origin URL is unreachable, or the requested object does not exist at the origin.	Verify that the back-to-origin URL is valid and accessible. For more information, see Back-to-origin rules overview.
`Read body from mirror host failed, please check your mirror host`	OSS cannot read data from the origin.	Verify that the origin specified in the back-to-origin URL is reachable and that objects stored there are accessible.
`Bytes read is not equal to expected`	The data received from the origin is missing or invalid.	Verify that the origin can send complete data to OSS without interruption.
`MD5 in header() is not equal to MD5 calculated`	The MD5 hash of the object retrieved from the origin does not match the `Content-MD5` value in the back-to-origin request. The object is not saved to OSS.	Check the origin's services and network connectivity to identify the source of the data integrity issue.
`The object you specified already exists and can not be overwritten`	The object already exists in OSS and cannot be overwritten.	Call ListObjects to confirm whether the object exists and check its overwrite permissions.
`The object you specified is immutable`	The bucket is protected by a retention policy, so the object retrieved from the origin cannot be written to it.	Call GetBucketWorm to check whether a retention policy is applied to the bucket.
`Meta is too large`	The total size of the object's user metadata exceeds the 8 KB limit.	Reduce the size of the user metadata. The combined size of all user metadata for a single object cannot exceed 8 KB.
`Mirror request is rejected by QoS`	The queries per second (QPS) for mirroring-based back-to-origin exceeds the default limit.	Reduce the QPS for mirroring-based back-to-origin requests. Default limits apply per region: 2,000 QPS and 2 Gbit/s in regions in China; 1,000 QPS and 1 Gbit/s in regions outside China. To request a higher limit, contact technical support.
`Error status : 0 from mirror host, should return 200 OK`	The origin rejected the back-to-origin request due to an interception policy, such as a firewall or BT-Panel access control rule.	Disable the interception policy on the origin firewall or BT-Panel.