[
https://issues.apache.org/jira/browse/MAPREDUCE-326?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12833251#action_12833251
]
Owen O'Malley commented on MAPREDUCE-326:
-----------------------------------------
{quote}
This is not a risk since the API is marked "unstable" so we retain the freedom
to change it in any way we like.
{quote}
That is completely untrue. It is mark unstable as a warning to users. I would
reject any incompatible change to the API. We should mark the base classes
(Mapper, Reducer, InputFormat, OutputFormat, Partitioner, RecordReader,
RecordWriter, Partitioner, *Context) as stable. Pig is already using the new
APIs and so are a lot of other business critical applications.
{quote}
You can think of this change as a refactor to make the MapReduce shuffle more
accessible to framework developers
{quote}
My suggestion does it far more easily and with no application disruption.
Furthermore, this *does* double the interface, which is already extremely wide.
{quote}
the new (context objects) MapReduce API is implemented in library code
{quote}
But it is the primary interface that our users use. If you are proposing that
we make this the "real" interface, then I've already expressed my -1. Users
don't want to think in bytes.
> The lowest level map-reduce APIs should be byte oriented
> --------------------------------------------------------
>
> Key: MAPREDUCE-326
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-326
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Reporter: eric baldeschwieler
> Attachments: MAPREDUCE-326-api.patch, MAPREDUCE-326.pdf
>
>
> As discussed here:
> https://issues.apache.org/jira/browse/HADOOP-1986#action_12551237
> The templates, serializers and other complexities that allow map-reduce to
> use arbitrary types complicate the design and lead to lots of object creates
> and other overhead that a byte oriented design would not suffer. I believe
> the lowest level implementation of hadoop map-reduce should have byte string
> oriented APIs (for keys and values). This API would be more performant,
> simpler and more easily cross language.
> The existing API could be maintained as a thin layer on top of the leaner API.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
