hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Lars Hofhansl (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-9000) Linear reseek in Memstore
Date Tue, 11 Mar 2014 20:34:53 GMT

    [ https://issues.apache.org/jira/browse/HBASE-9000?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13930909#comment-13930909
] 

Lars Hofhansl commented on HBASE-9000:
--------------------------------------

HBASE-9778 is committed now. It allows a configurable optional look ahead in ExplicitColumn
tracker. Hence it'll do it in both Memstore and StoreScanner. I did look into doing that in
StoreFileScanner, but most of the time of a reseek is spent before we even get to StoreFileScanner
(checking whether we are forward seeking, checking whether we're still on the same block,
seeking every HFile forward, etc).


> Linear reseek in Memstore
> -------------------------
>
>                 Key: HBASE-9000
>                 URL: https://issues.apache.org/jira/browse/HBASE-9000
>             Project: HBase
>          Issue Type: Improvement
>          Components: Performance
>    Affects Versions: 0.89-fb
>            Reporter: Shane Hogan
>            Priority: Minor
>             Fix For: 0.89-fb
>
>         Attachments: hbase-9000-benchmark-program.patch, hbase-9000-port-fb.patch, hbase-9000.patch
>
>
> This is to address the linear reseek in MemStoreScanner. Currently reseek iterates over
the kvset and the snapshot linearly by just calling next repeatedly. The new solution is to
do this linear seek up to a configurable maximum amount of times then if the seek is not yet
complete fall back to logarithmic seek.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Mime
View raw message