[HBASE-4071] Data GC: Remove all versions > TTL EXCEPT the last written version

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.92.0
• Hadoop Flags: Reviewed
• Release Note: Even if older than TTL, keep N versions; e.g. if N is 1, we'll purge all versions but the most recent written even if this one version is older than TTL.
• Assignee: Lars Hofhansl
• Reporter: Michael Stack
• Created: 07/Jul/11 03:54
• Updated: 20/Nov/15 11:52
• Resolved: 24/Aug/11 05:18

Description

We were chatting today about our backup cluster. What we want is to be able to restore the dataset from any point of time but only within a limited timeframe – say one week. Thereafter, if the versions are older than one week, rather than as we do with TTL where we let go of all versions older than TTL, instead, let go of all versions EXCEPT the last one written. So, its like versions==1 when TTL > one week. We want to allow that if an error is caught within a week of its happening – user mistakenly removes a critical table – then we'll be able to restore up the the moment just before catastrophe hit otherwise, we keep one version only.

Issue Links

• is related to: HBASE-3842 Refactor Coprocessor Compaction API
• relates to: HBASE-2600 Change how we do meta tables; from tablename+STARTROW+randomid to instead, tablename+ENDROW+randomid

Sub-Tasks

• Add documentation for HBASE-4071: Closed
• Add DEFAULT_MIN_VERSIONS to HColumnDescriptor.DEFAULT_VALUES: Closed