[HBASE-24955] Clarify patch upgrade compatibility guarantees

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0.0-alpha-1, 2.3.3, 1.7.0
• Component/s: documentation
• Assignee: Unassigned
• Reporter: Bharath Vissapragada
• Created: 26/Aug/20 16:04
• Updated: 26/Aug/20 16:04

Description

Per the compatibility guidelines (specifically section "Client-Server wire protocol compatibility
") which says "We could only allow upgrading the server first. I.e. the server would be backward compatible to an old client, that way new APIs are OK."

This gives an impression that it is fine to break API compatibility in patch upgrades and expect the users to upgrade server binaries first before upgrading clients. However, when considering a back-port of HBASE-24765, it was noted by zhangduo and ndimiduk that this compatibility shouldn't be broken. Seems like something that should be clarified in the docs.