OBS (compatible with OpenStack Swift) returns an HTTP response after receiving and processing a request.

Syntax

Status Line: HTTP-Version Status-Code Reason-Phrase
Response Headers
<Conditional Response Body>

Status Line

The first line of a response is the Status-Line, consisting of the protocol version, numeric status code, and textual phrases. The previous elements are separated by spaces. See Table 1.

**Table 1** Status line elements
Element	Description
HTTP-Version	HTTP version. OBS (compatible with OpenStack Swift) uses HTTP 1.1.
Status-Code	Status code, which describes the response type.
Reason-Phrase	Reason phrase, which describes the status code in a short text.

The first digit of the status code defines the response type. The last two digits do not have this function. There are five types of status codes, categorized based on the first digit. The categories are described in Table 2.

**Table 2** Status codes in OBS (compatible with OpenStack Swift)
Status Code	Description
1xx	The server has received but is still processing the request.
2xx	The request has been received, understood, and accepted.
3xx	The client must take further actions to complete the request.
4xx	There was an error on the client side. The request contains bad syntax or cannot be fulfilled.
5xx	There was an error on the server side. The server failed to fulfill a valid request.

A 1xx status code is a provisional response. Table 3 describes the 1xx status code in OBS (compatible with OpenStack Swift).

**Table 3** 1xx status code
Status Code	Description	Returned After
100 Continue	The initial part of the request has been received and has not yet been rejected by the server and the client should continue with its request.	PUT Object POST Object

A 2xx status code indicates that a request has been successfully processed by the server. Table 4 describes all 2xx status codes in OBS (compatible with OpenStack Swift).

**Table 4** 2xx status codes
Status Code	Description	Returned After
200 OK	The server has received and accepted the client's request.	List Objects GET Object GET Object Metadata
201 Created	The response may contain an XML file. The XML file describes the response content.	PUT Container PUT Object
202 Accepted	The server has received the request.	POST operations (Update object metadata)
204 No Content	The server has processed a request successfully, but no content was returned.	HEAD Container POST operations on access control lists (ACLs) DELETE Object DELETE Container

A 3xx status code indicates that a request can be successfully processed only after being redirected. Table 5 describes all 3xx status codes in OBS (compatible with OpenStack Swift).

**Table 5** 3xx status codes
Status Code	Description	Returned After
303 See Other	The client can use another URL to get a specific object.	POST operations (provided that redirection parameters in requests are valid.)
304 Not Modified	After the client sent a GET request with the required modification time, access was allowed but the resource was not modified after the specified time.	The resource is obtained but the modification time condition is not met.
307 Moved Temporarily	A request has been redirected.	A request is redirected after it fails to be processed by the server.

A 4xx status code indicates that a request failed to be processed due to a client error. A 4xx status code is returned together with a response body containing error details. 4xx status codes apply to all request methods except HEAD. For more details, see the definition of 4xx status codes.

**Table 6** 4xx status codes
Status Code	Description	Returned After
400 Bad Request	The syntax of a request was incorrect.	A request in incorrect syntax or containing incorrect parameters is sent.
401 Unauthorized	The request could not be authenticated.	The user does not exist or the authentication information in a sent request is incorrect.
403 Forbidden	The server refused the request.	The user does not have sufficient permissions.
404 Not Found	The requested resource does not exist.	The requested resource (such as a container or object) does not exist.
411 Length Required	The request header did not contain the required Content-Length or Transfer-Encoding field.	A request containing no Content-Length header is sent.
412 Precondition Failed	Conditions are not met.	Conditions are not met, if the object query request contains the If-Match or If-None-Match header.
413 Request Entity Too Large	Insufficient user quota.	User storage capacity exceeds user quota when uploading or replicating objects.

A 5xx status code means that the server encountered an error when processing the request or failed to process the request. Except for HEAD requests, a 5xx status code is returned together with a response body containing error details. Table 7 describes all 5xx status codes in OBS (compatible with OpenStack Swift).

**Table 7** 5xx status codes
Status Code	Description	Returned After
500 Internal Error	An internal error occurred on the server.	An internal error occurred on the server.
503 Service Unavailable	The server was overloaded.	The server is processing too many requests.

Response Headers

A response header is the information appended to a response, as described in Table 8. Response headers describe the server and contain further information about accessing the requested resource.

**Table 8** Response headers
Header	Description	Applicable To
Content-Length	Length of a response body	All responses (except those responses whose transfer-encoding is chunked)
Date	The date and time when a response was generated	All responses
X-Trans-Id	A unique identifier generated by OBS (compatible with OpenStack Swift) for a request	All responses
Content-Type	The object type returned	All responses

OBS (compatible with OpenStack Swift) normalizes the content of the Content-Type. The content returned is different from that returned by OpenStack Swift in the following way:

Content-Type content uses only charset=UTF-8 (UTF in uppercase).

Response Body

In OBS (compatible with OpenStack Swift), a response body is included in a request response under the following conditions:

GET Object
If the object is not blank, the response body is the object body.
GET Account or Container
The response body is account or container information.

Client error
The response body describes the client error in detail in XML format so that the user can perform further operations. For details, see client error response codes.
Server error
The response body describes the server error in detail in XML format so that the user can perform further operations.

Error Responses

OBS (compatible with OpenStack Swift) returns an error response if a request is incorrect, the permission is incorrect, or the requested container or object is not found. An error response describes the error. When you upload an object, if permissions cannot be authenticated, the following information (in HTML format) is displayed:

<html><h1>Unauthorized</h1><p>This server could not verify that you are authorized to access the document you requested.</p></html>