hadoop-common-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Gopal V (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HADOOP-11901) BytesWritable supports only up to ~700MB (instead of 2G) due to integer overflow.
Date Sat, 02 May 2015 19:58:06 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-11901?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14525437#comment-14525437
] 

Gopal V commented on HADOOP-11901:
----------------------------------

If the only goal is overflow prevention you can skip a multiply and do {{size + size/2}} -
the jdk bin-search bug was similar.

> BytesWritable supports only up to ~700MB (instead of 2G) due to integer overflow.
> ---------------------------------------------------------------------------------
>
>                 Key: HADOOP-11901
>                 URL: https://issues.apache.org/jira/browse/HADOOP-11901
>             Project: Hadoop Common
>          Issue Type: Improvement
>            Reporter: Reynold Xin
>            Assignee: Reynold Xin
>         Attachments: HADOOP-11901.diff
>
>
> BytesWritable.setSize increases the buffer size by 1.5 each time ( * 3 / 2). This is
an unsafe operation since it restricts the max size to ~700MB, since 700MB * 3 > 2GB.
> I didn't write a test case for this case because in order to trigger this, I'd need to
allocate around 700MB, which is pretty expensive to do in a unit test. Note that I didn't
throw any exception in the case integer overflow as I didn't want to change that behavior
(callers to this might expect a java.lang.NegativeArraySizeException).



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

Mime
View raw message