crunch-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Josh Wills (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CRUNCH-437) Fix Crunch Spark duplicate value aggregation
Date Sun, 06 Jul 2014 18:57:34 GMT

    [ https://issues.apache.org/jira/browse/CRUNCH-437?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14053185#comment-14053185
] 

Josh Wills commented on CRUNCH-437:
-----------------------------------

Ack, good point. Thanks!

> Fix Crunch Spark duplicate value aggregation
> --------------------------------------------
>
>                 Key: CRUNCH-437
>                 URL: https://issues.apache.org/jira/browse/CRUNCH-437
>             Project: Crunch
>          Issue Type: Bug
>            Reporter: Josh Wills
>             Fix For: 0.8.4, 0.11.0
>
>         Attachments: CRUNCH-437.patch
>
>
> The current Crunch-on-Spark mapside combiner uses a Multimap of key-value pairs to cache
values for local aggregation. This is awesome, except it means that identical key-value outputs
before a shuffle will only have one copy in the Multimap, which means that the aggregation
counts may not be correct. We should fix it to use a proper Map<K, List<V>> to
ensure that duplicate values are aggregated correctly.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Mime
View raw message