Package org.apache.hadoop.ozone.om.request.validation

Annotation Type OMLayoutVersionValidator

@Retention(RUNTIME) @Target(METHOD) public @interface OMLayoutVersionValidator
An annotation to mark methods that do certain request validations based on the server's layout version and capability to perform a certain operation. The methods annotated with this annotation are collected by the ValidatorRegistry class during the initialization of the server. The conditions describe the specific use case in which the validator should be applied to the request. See VersionExtractor for getting all the supported different Versioned component's actual version. The validator method will be applied to the specified request type(s). To help keep these methods simple and straightforward use inheritance and annotate the override method that just calls the method defined in the parent instead of specifying multiple request types. Note that the aim is to have these validators together with the request processing code, so the handling of these specific situations are easy to find. The annotated methods have to have a fixed signature. A RequestProcessingPhase.PRE_PROCESS phase method is running before the request is processed by the regular code. Its signature has to be the following: - it has to be static and idempotent - it has to have two parameters - the first parameter is an OzoneManagerProtocolProtos.OMRequest - the second parameter is a ValidationContext - the method has to return the modified request, or throw a ServiceException in case the request is considered to be invalid - the method does not need to care about preserving the request it gets, the original request is captured and saved by the calling environment. A RequestProcessingPhase.POST_PROCESS phase method is running once the OzoneManagerProtocolProtos.OMResponse is calculated for a given request. Its signature has to be the following: - it has to be static and idempotent - it has three parameters - similalry to the pre-processing validators, first parameter is the OMRequest, the second parameter is the OMResponse, and the third parameter is a ValidationContext. - the method has to return the modified OMResponse or throw a ServiceException if the request is considered invalid based on response. - the method gets the request object that was supplied for the general request processing code, not the original request, while it gets a copy of the original response object provided by the general request processing code.

  • Required Element Summary

    Required Elements
    Modifier and Type
    Required Element
    Description
    OMLayoutFeature
    applyBefore
    The version before which the validator needs to run.
    org.apache.hadoop.ozone.request.validation.RequestProcessingPhase
    processingPhase
    Defines if the validation has to run before or after the general request processing.
    org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos.Type[]
    requestType
    The type(s) of the request(s) handled by this validator method.

  • Element Details

    • processingPhase

      org.apache.hadoop.ozone.request.validation.RequestProcessingPhase processingPhase
      Defines if the validation has to run before or after the general request processing.
      Returns:
      if this is a pre or post processing validator

    • requestType

      org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos.Type[] requestType
      The type(s) of the request(s) handled by this validator method. In case you are considering to specify multiple request types, please read the note above on using multiple request types with this kind of validator method.
      Returns:
      the requestType(s) onto which the validator should be applied

    • applyBefore

      OMLayoutFeature applyBefore
      The version before which the validator needs to run. The validator will run only for requests having a version which precedes the specified version.