HADOOP-13493. Compatibility Docs should clarify the policy for what takes precedence when a conflict is found (templedf via rkanter)

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Robert Kanter 2017-11-30 07:39:15 -08:00
parent 0e560f3b8d
commit 75a3ab88f5

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@ -117,13 +117,7 @@ Compatibility types
Developers SHOULD annotate all Hadoop interfaces and classes with the
@InterfaceAudience and @InterfaceStability annotations to describe the
intended audience and stability. Annotations may be at the package, class, or
member variable or method level. Member variable and method annotations SHALL
override class annotations, and class annotations SHALL override package
annotations. A package, class, or member variable or method that is not
annotated SHALL be interpreted as implicitly
[Private](./InterfaceClassification.html#Private) and
[Unstable](./InterfaceClassification.html#Unstable).
intended audience and stability.
* @InterfaceAudience captures the intended audience. Possible values are
[Public](./InterfaceClassification.html#Public) (for end users and external
@ -134,6 +128,27 @@ etc.), and [Private](./InterfaceClassification.html#Private)
* @InterfaceStability describes what types of interface changes are permitted. Possible values are [Stable](./InterfaceClassification.html#Stable), [Evolving](./InterfaceClassification.html#Evolving), and [Unstable](./InterfaceClassification.html#Unstable).
* @Deprecated notes that the package, class, or member variable or method could potentially be removed in the future and should not be used.
Annotations MAY be applied at the package, class, or method level. If a method
has no privacy or stability annotation, it SHALL inherit its intended audience
or stability level from the class to which it belongs. If a class has no
privacy or stability annotation, it SHALL inherit its intended audience or
stability level from the package to which it belongs. If a package has no
privacy or stability annotation, it SHALL be assumed to be
[Private](./InterfaceClassification.html#Private) and
[Unstable](./InterfaceClassification.html#Unstable),
respectively.
In the event that an element's audience or stability annotation conflicts with
the corresponding annotation of its parent (whether explicit or inherited), the
element's audience or stability (respectively) SHALL be determined by the
more restrictive annotation. For example, if a
[Private](./InterfaceClassification.html#Private) method is contained
in a [Public](./InterfaceClassification.html#Public) class, then the method
SHALL be treated as [Private](./InterfaceClassification.html#Private). If a
[Public](./InterfaceClassification.html#Public) method is contained in a
[Private](./InterfaceClassification.html#Private) class, the method SHALL be
treated as [Private](./InterfaceClassification.html#Private).
#### Use Cases
* [Public](./InterfaceClassification.html#Public)-[Stable](./InterfaceClassification.html#Stable) API compatibility is required to ensure end-user programs and downstream projects continue to work without modification.