[
https://issues.apache.org/jira/browse/HADOOP-6949?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12999469#comment-12999469
]
Suresh Srinivas commented on HADOOP-6949:
-----------------------------------------
> As I said in my comment in HDFS-1583, Java does not support heterogeneous
> arrays, see ArrayStoreException for the reference. So we don't need to
> support such generic semantic. We can assume the array is strictly
> homogeneous.
Assuming you are talking about labeling the array only for the type it carries,
the approach you are suggesting will not work for heartbeat response, where
DatanodeCommand[] is the response, with array elements carrying subtypes of
DatanodeCommand, which should be labelled once per array element.
Also a protocol could choose to give a response of Object[]. Not sure I
understand the reference you posted and how it is relevant to this discussion.
I prefer this issue focusing on primitive types and opening a separate jira for
non-primitive type, as I think it needs more discussion.
> Reduces RPC packet size for primitive arrays, especially long[], which is
> used at block reporting
> -------------------------------------------------------------------------------------------------
>
> Key: HADOOP-6949
> URL: https://issues.apache.org/jira/browse/HADOOP-6949
> Project: Hadoop Common
> Issue Type: Improvement
> Components: io
> Reporter: Navis
> Assignee: Matt Foley
> Fix For: 0.23.0
>
> Attachments: ObjectWritable.diff, arrayprim.patch, arrayprim_v4.patch
>
> Original Estimate: 10m
> Remaining Estimate: 10m
>
> Current implementation of oah.io.ObjectWritable marshals primitive array
> types as general object array ; array type string + array length + (element
> type string + value)*n
> It would not be needed to specify each element types for primitive arrays.
--
This message is automatically generated by JIRA.
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
