[
https://issues.apache.org/jira/browse/MAPREDUCE-326?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12834340#action_12834340
]
Arun C Murthy commented on MAPREDUCE-326:
-----------------------------------------
Jay - it would really help if you could explain your requirements better.
{quote}
Specifically, the option to launch an arbitrary runtime and give it it's
inputsplit information over STDIN would be really useful for us, could tell our
Mapper and Reducer classes if they need to initialize any business services
prior to the main run, recycle those services across runs, allow more
flexibility with custom serializers, make it easier to involve a complicated
series of InputFormats.. (we need CombineFileInput and MultipleInput and a
custom internal SerDe, which in some cases necessitates redundant "gather jobs"
prior to "processing jobs").
{quote}
The _current_ proposal has *nothing* to do with passing input-split over STDIN
or supporting non-Java applications better and so on, we are only debating the
apis for the Java MR framework.
> 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.
