Merge pull request #16419 from dsouzai/deprecationPolicy

Add Deprecation Process doc

doc/processes/deprecation.md

@@ -0,0 +1,46 @@
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+Copyright (c) 2022, 2022 IBM Corp. and others
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+This program and the accompanying materials are made available under
+the terms of the Eclipse Public License 2.0 which accompanies this
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+
+# Eclipse OpenJ9 Deprecation Process
+
+To deprecate a documented OpenJ9 option, behaviour, or feature, follow
+the process described below:
+
+1. Determine the **Java version** the deprecation is to take effect.
+2. Announce the deprecation that is to occur in version n in the
+release notes of version n-1. Furthermore, update any documentation
+to warn about the upcoming changes.
+3. Change the codebase in the `master` branch following the split for
+version n-1, as well as update any relevant documentation,
+to reflect the deprecation.
+4. Remove any relevant documentation once all versions prior to the
+version n go out of service.
+
+## Important Notes
+
+* Deprecation normally only occurs when a new Java version is released; this
+should not be confused with a new OpenJ9 version, which may not
+necessarily include a new Java version.
+* If an OpenJ9 release does not include Java version n-1 (i.e., the version
+used to announce the deprecation), the release notes can still announce the
+upcoming deprecation; however, this notice should be added to all subsequent
+release notes until the OpenJ9 release that includes Java version n.

doc/processes/release_process.md

@@ -101,6 +101,9 @@ Note, detecting regressions will be difficult in the open project
 given the limited hardware resources available.  Work is being done at
 Adoptium to enable performance testing.
 
+## Deprecation
+See [Eclipse OpenJ9 Deprecation Process](deprecation.md).
+
 # Release Process
 
 1. Pick a candidate OpenJ9 level to mark as the initial release candidate.  This