hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Lars Hofhansl (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-4583) Integrate RWCC with Append and Increment operations
Date Sat, 29 Oct 2011 22:05:39 GMT

    [ https://issues.apache.org/jira/browse/HBASE-4583?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13139468#comment-13139468

Lars Hofhansl commented on HBASE-4583:

Looking at the code. There are some other weird things:
1. HRegion.applyFamilyMapToMemstore calls Store.add for each KV, which in turns calls Memstore.add.
At each iteration both the Store and the Memstore take and release the read lock. Should be
more efficient to pass a set of only take the locks once (at the expense of slightly reduce
lock granularity).
2. Both HRegion.increment and HRegion.append (which is modeled after increment) update the
memstore first, and then write the WAL. If the WAL sync fails there would be uncommitted state
in the memstore. Fixing this should either incur a performance penalty (need to sync the WAL
with the update.readLock held, or require memstore rollback (like we do for put now).

I think these two should have separate jiras.

> Integrate RWCC with Append and Increment operations
> ---------------------------------------------------
>                 Key: HBASE-4583
>                 URL: https://issues.apache.org/jira/browse/HBASE-4583
>             Project: HBase
>          Issue Type: Bug
>            Reporter: Lars Hofhansl
>            Assignee: Lars Hofhansl
>             Fix For: 0.94.0
> Currently Increment and Append operations do not work with RWCC and hence a client could
see the results of multiple such operation mixed in the same Get/Scan.
> The semantics might be a bit more interesting here as upsert adds and removes to and
from the memstore.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira


View raw message