[HBASE-6233] [brainstorm] snapshots: hardlink alternatives

• Type: Brainstorming
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Assignee: Unassigned
• Reporter: Matteo Bertozzi
• Created: 18/Jun/12 18:30
• Updated: 13/Jun/22 16:43
• Resolved: 13/Jun/22 16:43

Description

Discussion ticket around snapshots and hardlink alternatives.
(See the HDFS-3370 discussion about hardlink and implementation problems)

(taking for a moment WAL out of the discussion and focusing on hfiles)
With hardlinks available taking snapshot will be fairly easy:

• (hfiles are immutable)
• hardlink to .snapshot/name to take snapshot
• hardlink from .snapshot/name to restore the snapshot
• No code change needed (on fs.delete() only one reference is deleted)

but we don't have hardlinks, what are the alternatives?

Issue Links

• relates to: HBASE-6230 [brainstorm] "Restore" snapshots for HBase 0.96
• relates to: HBASE-6055 Offline Snapshots in HBase 0.96