[
https://issues.apache.org/jira/browse/TEZ-2442?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15208888#comment-15208888
]
Bikas Saha commented on TEZ-2442:
---------------------------------
IIRC, this is the same for both kinds of shuffle. Because consumers can fetch
and merge spills as they happen in a pipelined manner as they get the DME for
each spilled output. The physical fetch method (HTTP or FS) is likely not
relevant. [~rajesh.balamohan] can correct me if this is inaccurate.
> Support DFS based shuffle in addition to HTTP shuffle
> -----------------------------------------------------
>
> Key: TEZ-2442
> URL: https://issues.apache.org/jira/browse/TEZ-2442
> Project: Apache Tez
> Issue Type: Improvement
> Affects Versions: 0.5.3
> Reporter: Kannan Rajah
> Assignee: Kannan Rajah
> Attachments: HDFS_based_shuffle_v2.pdf, Tez Shuffle using DFS.pdf,
> hdfs_broadcast_hack.txt, tez_hdfs_shuffle.patch
>
>
> In Tez, Shuffle is a mechanism by which intermediate data can be shared
> between stages. Shuffle data is written to local disk and fetched from any
> remote node using HTTP. A DFS like MapR file system can support writing this
> shuffle data directly to its DFS using a notion of local volumes and retrieve
> it using HDFS API from remote node. The current Shuffle implementation
> assumes local data can only be managed by LocalFileSystem. So it uses
> RawLocalFileSystem and LocalDirAllocator. If we can remove this assumption
> and introduce an abstraction to manage local disks, then we can reuse most of
> the shuffle logic (store, sort) and inject a HDFS API based retrieval instead
> of HTTP.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
