This section provides general information about SCSP UPDATE that applies to both named and unnamed objects.
The UPDATE request is formatted as a simple HTTP request using the PUT method.
SCSP Method | HTTP Method | RFC 7231 Section |
|---|---|---|
SCSP UPDATE | PUT |
Special Query Arguments
replicate | Protects rapid updates | Important: Objects can be updated at a maximum frequency of once per second. Updating more frequently can cause unpredictable results with the stored object version and can trigger a 409 (Conflict) error. If your application updates objects faster than once per second, include the |
|---|---|---|
newname | Renames object | To rename a named object within the same bucket, use the newname query argument, which provides a new name with the update request (PUT, COPY, APPEND). After you rename an object, requests for the original name return a 404 Not Found and the prior search metadata is removed. (Note that the |
preserve | Updates custom headers | PUT only saves new headers, but the |
UPDATE for named objects
UPDATE is a request to the storage cluster to modify a specific named object or alias object with new content. The UPDATE request is formatted as a simple HTTP request using the PUT method:
PUT /bucket/file.txt HTTP/1.1 Host: cluster.example.com User-Agent: Swarm Client/0.1 Content-Length: 43402 Expect: 100-continue Content-Type: image/jpeg Content-Language: en/us, x-pig-latin Content-Version: 42 Last-Modified: Wed, 1 Sept 2010 15:59:02 GMT Created-Date: Wed, 1 Sept 2010 15:59:02 GMT CRLF [ content ]
UPDATE for unnamed objects
The UPDATE request is formatted as a simple HTTP request using the PUT method. The normal response to a PUT request, similar to a POST, is a 201 Created response.
PUT /06eec5e2c3f1aadcb41ef7fd52adc049 HTTP/1.1 Host: cluster.example.com User-Agent: Swarm Client/0.1 Content-Length: 43402 Expect: 100-continue Content-Type: image/jpeg Content-Language: en/us, x-pig-latin Content-Version: 42 Last-Modified: Wed, 1 Sept 2010 15:59:02 GMT Created-Date: Wed, 1 Sept 2010 15:59:02 GMT CRLF [ content ]
PUT returns a 404 Not Found error if the object name or UUID you specify in the command does not exist.
Note
The object can be erasure-coded, which has a smaller storage footprint, if a non-erasure-coded object is updated and the update causes the object to meet the criteria described in Erasure Coding.
UPDATE for alias objects
To update alias object, adding alias=yes is optional because this method applies only to mutable objects.
If UPDATE succeeds on an alias object, the content sent in the body of the request will be written as a new object. The first line of the HTTP PUT will be updated to point to the new object, and the original UUID of the object is returned to the client.
Normal Responses to UPDATE
For a list of response headers, see SCSP Headers.
Error Responses to UPDATE
If you execute the UPDATE method on an object in a domain but the domain does not exist or is not in the content cache on the node that receives the request, Swarm responds with 409 Conflict.
Rapid updates
Rapid updates of an object can trigger a 409 Conflict error, that a "Later version already exists."
Rapid updates or overwrites to an object in a versioned bucket can cause temporary listing inconsistency, even when replication=immediate is used (default with Gateway). Those unlisted versions can still be accessed directly by the versionid. Using a 1-second delay should avoid this.