[HBASE-7291] Simple Log Roll Snapshot

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Assignee: Unassigned
• Reporter: Jonathan Hsieh
• Created: 06/Dec/12 08:40
• Updated: 15/Jun/22 20:50
• Resolved: 19/Jan/13 15:34

Description

This snapshot will likely be the cheapest snapshot taking method – it rolls or drops a marker in the hlog when a snapshot request is made. This approach can be seen as an improvement upon copytable/export with similar consistency guarantees. Specifically, there will be "ragged edges", and happens-before relation on clients may not be consistent from a client's point of view but it will be useable for many backup for disaster recovery use cases.

For example:

If client 1 writes row a to region A and then row b to region B, a client happens-before enforcing snapshot would only be allowed to have neither a nor b, only a, or both a and b. Having only b should not be possible. This outcome would be possible with the log-roll snapshot.