[HBASE-14949] Resolve name conflict when splitting if there are duplicated WAL entries

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.3.0, 2.0.0
• Component/s: wal
• Hadoop Flags: Reviewed
• Release Note: Now we can write duplicated WAL entries into different WAL files. This feature is required by the replication consistency fix and new implementation of WAL writer.
• Assignee: Duo Zhang
• Reporter: Heng Chen
• Created: 08/Dec/15 08:37
• Updated: 23/Jun/22 20:05
• Resolved: 19/Feb/16 01:44

Description

The AsyncFSHLog introduced in HBASE-14790 may write same WAL entries to different WAL files. WAL entry itself is idempotent so replay is not a problem but the intermediate file name and final name when splitting is constructed using the lowest or highest sequence id of the WAL entries written, so it is possible that different WAL files will have same intermediate or final file name when splitting. In the currentm implementation, this will cause split fail or data loss. We need to solve this.