huaxiang sun created HBASE-17241: ------------------------------------ Summary: Avoid compacting already compacted mob files with _del files Key: HBASE-17241 URL: https://issues.apache.org/jira/browse/HBASE-17241 Project: HBase Issue Type: Improvement Components: mob Affects Versions: 2.0.0 Reporter: huaxiang sun Assignee: huaxiang sun
Today if there is only one file in the partition, and there is no _del files, the file is skipped. With del file, the current logic is to compact the already-compacted file with _del file. Let's say there is one mob file regionA20161101***, which was compacted. On 12/1/2016, there is _del file regionB20161201**_del, mob compaction kicks in, regionA20161101*** is less than the threshold, and it is picked for compaction. Since there is a _del file, regionA20161101**** and regionB20161201***_del are compacted into regionA20161101**_1 . After that, regionB20161201**_del cannot be deleted since it is not a allFile compaction. The next mob compaction, regionA20161101**_1 and regionB20161201**_del will be picked up again and be compacted into regionA20161101***_2. So in this case, it will cause more unnecessary IOs. -- This message was sent by Atlassian JIRA (v6.3.4#6332)