hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "dhruba borthakur (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-5074) support checksums in HBase block cache
Date Tue, 28 Feb 2012 18:19:46 GMT

    [ https://issues.apache.org/jira/browse/HBASE-5074?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13218423#comment-13218423
] 

dhruba borthakur commented on HBASE-5074:
-----------------------------------------

@Stack: I am pretty sure that the feature is on by default (but let me check and get back
to you). Regarding the exception message about CRC32C, the Enum is trying to create this object
but failing to do so because the Hadoop library in Hadoop 1.0 does not have support for this
one (Hadop 2.0 supports CRC32C). The reason I kept that is because people who might already
be experimenting with Hadoop 2.0 will get this support out-of-the-box. But I agree that it
will be good to get rid of this exception message at startup. Do you have any suggestions
on this one?

@Todd: will take your excellent suggestion and make the majorVersion inside HFileBlock as
a "static". Thanks.

@Ted: Thanks for your comments. Will try to gather metrics in my cluster and post to this
JIRA.
                
> support checksums in HBase block cache
> --------------------------------------
>
>                 Key: HBASE-5074
>                 URL: https://issues.apache.org/jira/browse/HBASE-5074
>             Project: HBase
>          Issue Type: Improvement
>          Components: regionserver
>            Reporter: dhruba borthakur
>            Assignee: dhruba borthakur
>         Attachments: D1521.1.patch, D1521.1.patch, D1521.10.patch, D1521.10.patch, D1521.10.patch,
D1521.10.patch, D1521.10.patch, D1521.2.patch, D1521.2.patch, D1521.3.patch, D1521.3.patch,
D1521.4.patch, D1521.4.patch, D1521.5.patch, D1521.5.patch, D1521.6.patch, D1521.6.patch,
D1521.7.patch, D1521.7.patch, D1521.8.patch, D1521.8.patch, D1521.9.patch, D1521.9.patch
>
>
> The current implementation of HDFS stores the data in one block file and the metadata(checksum)
in another block file. This means that every read into the HBase block cache actually consumes
two disk iops, one to the datafile and one to the checksum file. This is a major problem for
scaling HBase, because HBase is usually bottlenecked on the number of random disk iops that
the storage-hardware offers.

--
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

        

Mime
View raw message