[
https://issues.apache.org/jira/browse/HBASE-2162?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12804030#action_12804030
]
ryan rawson commented on HBASE-2162:
------------------------------------
If we want to replace get with a 1 row scan, we might have to do this work.
with my thoughts, it might be low cost to do a rippling lock.
Another alternative is to use a data structure that prevents half-rows from
being read by scanners.
This is a dangerous area we can and should do better in imho. The time is nigh!
> scanners need to obey row locks, a modest propsal
> -------------------------------------------------
>
> Key: HBASE-2162
> URL: https://issues.apache.org/jira/browse/HBASE-2162
> Project: Hadoop HBase
> Issue Type: Bug
> Reporter: ryan rawson
> Assignee: ryan rawson
> Fix For: 0.21.0
>
>
> 15:54 < dj_ryan> - next:
> 15:54 < dj_ryan> do next on Tree in memstore get rowid
> 15:55 < dj_ryan> acquire read lock on rowid (wait if necessary)
> 15:55 < dj_ryan> snapshot the entire row worth of data from memstore into
> scanner
> 15:55 < dj_ryan> release read lock on rowid
> 15:56 < dj_ryan> so if we get an insert on a row after the 'do next' which
> would call 'next' on the
> previous last value grabbed from the tree
> 15:56 < dj_ryan> we'd skip that one
> 15:56 < dj_ryan> which is fine
> 15:57 < dj_ryan> i guess the issue comes in when you have to next a bunch to
> get to the next row
> 15:57 < dj_ryan> but that is doable with a simple little while loop
> 15:57 < dj_ryan> this only applies to memstore
> 15:57 < dj_ryan> snapshot = hfile
> 15:57 < dj_ryan> since its immutable
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
