[
https://issues.apache.org/jira/browse/HBASE-9754?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13796445#comment-13796445
]
Lars Hofhansl commented on HBASE-9754:
--------------------------------------
I think in the *PolicyObserver.preStoreScannerOpen, we want the current MVCC
readpoint, rather than the store smallest readpoint.
I am also a bit concerned about passing 0 as readPt in some places, as that
makes everything visible. And for example it avoids setting the memstoreTs of
KV to 0 even when there are no old scanners open that could see that KV.
(In fact these were the consideration that made me think a correct patch for
this is hard)
> Consider eliminating threadlocals from MVCC code
> ------------------------------------------------
>
> Key: HBASE-9754
> URL: https://issues.apache.org/jira/browse/HBASE-9754
> Project: HBase
> Issue Type: Bug
> Reporter: Lars Hofhansl
> Assignee: Ted Yu
> Fix For: 0.98.0
>
> Attachments: 9754-rp-0.txt
>
>
> Brought up by [~vrodionov] and [[email protected]].
> Currently we use ThreadLocals to communicate the current readpoint between a
> RegionScanner and the Store\{File}Scanner's down the stack.
> Since ThreadLocals are not cheap we should consider whether it is possible to
> pass the readpoint through the call stack instead.
--
This message was sent by Atlassian JIRA
(v6.1#6144)
