[jira] [Created] (HBASE-10418) give blocks of smaller store files priority in cache

["Sergey Shelukhin (JIRA)" <ji...@apache.org>]

Sergey Shelukhin created HBASE-10418:
----------------------------------------

             Summary: give blocks of smaller store files priority in cache
                 Key: HBASE-10418
                 URL: https://issues.apache.org/jira/browse/HBASE-10418
             Project: HBase
          Issue Type: Improvement
          Components: regionserver
            Reporter: Sergey Shelukhin


That's just an idea at this point, I don't have a patch nor plan to make one in near future.
It's good for datasets that don't fit in memory especially; and if scans are involved. 
Scans (and gets in absence of bloom filters' help) have to read from all store files. Short range request will hit one block in every file.
If small files are more likely to be entirely available in memory, on average requests will hit less blocks from FS. 
For scans that read a lot of data, it's better to read blocks in sequence from a big file and blocks for small files from cache, rather than a mix of FS and cached blocks from different files, because the (HBase) blocks of a big file would be sequential in one HDFS block.



--
This message was sent by Atlassian JIRA
(v6.1.5#6160)