Versions Compared

Old Version 34

changes.mady.by.user Magnus Edenhill

Saved on

compared with

New Version 35

changes.mady.by.user Magnus Edenhill

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

  1. A new ApiVersionQueryRequest and Response type (version 0) will be added to allow clients to query the broker for supported API request types and versions.

    Code Block
    ApiVersionQueryRequest => ApiKeys
  ApiKeys = [INT16]
 
ApiVersionQueryResponse => ApiVersions
  ApiVersions = [ApiVersion]
    ApiVersion = ApiKey MinVersion MaxVersion
      ApiKey = INT16
      MinVersion = INT16
      MaxVersion = INT16
 

    1.  

  2. ApiVersionQueryRequest.ApiKeys semantics:

    1. Empty array (size 0): return all supported ApiVersions.

    2. Array of some ApiKeys: return ApiVersions for the requested keys.

  3. ApiVersionQueryResponse..MinVersion-MaxVersion semantics:
    1. MinVersion and MaxVersion dictates the lowest and highest supported API versions for the API key (inclusive).
    2. All versions in the MinVersion-MaxVersion must be supported by the broker. Specific version may be deprecated through protocol documentation but must still be supported (although it is fair to return an error code if the specific API supports it).

  4. Clients are recommended to use latest common supported API version.

  5. Deprecation of a protocol version will be done by marking a protocol version as deprecated in protocol documentation. Documentation shall also be used to indicate a protocol version that must not be used, or for any such information.For instance, say 0.9.0 had protocol versions [0] for api key 1. On trunk, version 1 of the api key was added. Users running off trunk started using version 1 of the api and found out a major bug. To rectify that version 2 of the api is added to trunk. For some reason, it is now deemed important to have version 2 of the api in 0.9.1 as well. To do so, version 1 and version 2 both of the api will be backported to the 0.9.1 branch. 0.9.1 broker will return 0 as min supported version for the api and 2 for the max supported version for the api. However, the version 1 should be clearly marked as deprecated on its documentation. It will be client's responsibility to make sure they are not using any such deprecated version to the best knowledge of the client at the time of development (or alternatively by configuration).

  6. Supported protocol versions obtained from a broker, is good only for current connection on which that information is obtained. In the event of disconnection, the client should obtain the information from the broker again, as the broker might have upgraded/ downgraded in the mean time.

  7. If a client faces connection closure on sending ApiVersionQueryRequest it could be due to following reasons.
    1. Broker does not support the ApiVersionQueryRequest API, the client should use some other method of determining the API versions to use (a safe default, configuration, error out, probing).
    2. Connection closure was caused by issues other than unknown API request.

...