hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ramkrishna.s.vasudevan (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-13320) 'hbase.bucketcache.size' configuration value is not correct in hbase-default.xml
Date Wed, 01 Apr 2015 06:02:54 GMT

    [ https://issues.apache.org/jira/browse/HBASE-13320?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14390036#comment-14390036
] 

ramkrishna.s.vasudevan commented on HBASE-13320:
------------------------------------------------

Thanks for checking this. Going through the complete calculation based on these configs, with
the default for 'hbase.bucketcache.size' being 65536 (64*1024), then the capacity that we
pass would be 64 * 1024*1024*1024 = 68719476736.
In the Bucketallocator assuming we have not configured any bucket sizes(going by default),
the maximum size would be (512 * 1024 + 1024). = 525312.
So 
{code}
 this.bucketCapacity = FEWEST_ITEMS_IN_BUCKET * bigItemSize;
{code}
would be 2101248 where the FEWEST_ITEMS_IN_BUCKET  = 4.
For the buckets array
{code}
buckets = new Bucket[(int) (availableSpace / bucketCapacity)];
{code}
which is approx 32704.  

When you configure it as 1, then the problem is this calculation leads to an array which is
less than 14.  So any default value which is more than 14 should be accounted for.  If for
any reason we have to keep the default ie. create 32704 sized bucket array only then I would
suggest we leave the default as is, but say that by default we would create buckets of size
64*1024*1024*1024.
Other wise we will just pass 64 in the hbase-default.xml so that we would alway get 64*1024*1024
which would lead to an array size of 31. I think that would be fine.  But before changing
it let us confirm on this size that has been calculated.
Any thoughts on this [~zjushch], [~saint.ack@gmail.com],[~ndimiduk],[~anoop.hbase]?


> 'hbase.bucketcache.size' configuration value is not correct in hbase-default.xml 
> ---------------------------------------------------------------------------------
>
>                 Key: HBASE-13320
>                 URL: https://issues.apache.org/jira/browse/HBASE-13320
>             Project: HBase
>          Issue Type: Bug
>          Components: hbase
>    Affects Versions: 2.0.0
>            Reporter: Y. SREENIVASULU REDDY
>            Assignee: Y. SREENIVASULU REDDY
>             Fix For: 2.0.0
>
>         Attachments: HBASE-13320.patch, HBASE-v2-13320.patch
>
>
> In  hbase-default.xml  file 
> * 'hbase.bucketcache.size' is not correct
> We either specify it as a float or in MB's and the default value that is mentioned is
never used
> {code}
> <property>
> <name>hbase.bucketcache.size</name>
> <value>65536</value>
> <source>hbase-default.xml</source>
> </property>
> {code}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message