[HBASE-20724] Sometimes some compacted storefiles are still opened after region failover - ASF JIRA

XML

Word

Printable

JSON

Details

Type: Bug
Status: Closed
Priority: Critical
Resolution: Fixed
Affects Version/s: 3.0.0-alpha-1, 1.3.0, 1.4.0, 1.5.0, 2.0.0
Fix Version/s: 3.0.0-alpha-1, 2.2.0, 2.3.0
Component/s: None
Labels:
None

Release Note:

Hide
Problem: This is an old problem since ~~HBASE-2231~~. The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL.

Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.

Show
Problem: This is an old problem since HBASE-2231 . The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL. Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.

Description

It is important that compacted storefiles of a given compaction execution are wholly opened or archived to insure data consistency. ie a storefile containing delete tombstones can be archived while older storefiles containing cells that were supposed to be deleted are left unarchived thereby undeleting those cells.

When a server fails compaction markers (in the wal edit) are used to determine which storefiles are compacted and should be excluded during region open (during failover). But the WALs containing compaction markers can be prematurely archived even though there are still compacted storefiles for that particular compaction event that hasn't been archived yet. Thus losing compaction information that needs to be replayed in the event of an RS crash. This is because hlog archiving logic only keeps track of flushed storefiles and not compacted ones.

https://issues.apache.org/jira/browse/HBASE-20704?focusedCommentId=16507680&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-16507680