[jira] [Commented] (HDFS-7040) HDFS dangerously uses @Beta methods from very old versions of Guava

["Christopher Tubbs (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HDFS-7040?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14202856#comment-14202856 ] 

Christopher Tubbs commented on HDFS-7040:
-----------------------------------------

I added a patch to fix this under MAPREDUCE-6083 for versions 2.6.0 and later which doesn't change the Guava version dependency. I suppose it could be back-ported to earlier versions (2.4/2.5), but it's probably not worth it since those versions are really only affected by {{MiniDFSCluster}}, and that's very limited.

> HDFS dangerously uses @Beta methods from very old versions of Guava
> -------------------------------------------------------------------
>
>                 Key: HDFS-7040
>                 URL: https://issues.apache.org/jira/browse/HDFS-7040
>             Project: Hadoop HDFS
>          Issue Type: Bug
>    Affects Versions: 2.4.0, 2.5.0, 2.4.1
>            Reporter: Christopher Tubbs
>              Labels: beta, deprecated, guava
>         Attachments: 0001-HDFS-7040-Avoid-beta-LimitInputStream-in-Guava.patch
>
>
> HDFS uses LimitInputStream from Guava. This was introduced as @Beta and is risky for any application to use.
> The problem is further exacerbated by Hadoop's dependency on Guava version 11.0.2, which is quite old for an active project (Feb. 2012).
> Because Guava is very stable, projects which depend on Hadoop and use Guava themselves, can use up through Guava version 14.x
> However, in version 14, Guava deprecated LimitInputStream and provided a replacement. Because they make no guarantees about compatibility about @Beta classes, they removed it in version 15.
> What should be done: Hadoop should updated its dependency on Guava to at least version 14 (currently Guava is on version 19). This should have little impact on users, because Guava is so stable.
> HDFS should then be patched to use the provided alternative to LimitInputStream, so that downstream packagers, users, and application developers requiring more recent versions of Guava (to fix bugs, to use new features, etc.) will be able to swap out the Guava dependency without breaking Hadoop.
> Alternative: While Hadoop cannot predict the marking and removal of deprecated code, it can, and should, avoid the use of @Beta classes and methods that do not offer guarantees. If the dependency cannot be bumped, then it should be relatively trivial to provide an internal class with the same functionality, that does not rely on the older version of Guava.



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