You are viewing a plain text version of this content. The canonical link for it is here.

Posted to issues@kylin.apache.org by "kangkaisen (JIRA)" <ji...@apache.org> on 2017/01/21 15:41:27 UTC

[jira] [Resolved] (KYLIN-2242) Directly write hdfs file in reducer is dangerous

     [ https://issues.apache.org/jira/browse/KYLIN-2242?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

kangkaisen resolved KYLIN-2242.
-------------------------------
       Resolution: Fixed
    Fix Version/s: v2.0.0

> Directly write hdfs file in reducer is dangerous
> ------------------------------------------------
>
>                 Key: KYLIN-2242
>                 URL: https://issues.apache.org/jira/browse/KYLIN-2242
>             Project: Kylin
>          Issue Type: Bug
>          Components: Job Engine
>    Affects Versions: v1.6.0
>            Reporter: kangkaisen
>            Assignee: kangkaisen
>             Fix For: v2.0.0
>
>         Attachments: KYLIN-2242.patch
>
>
> currently, Kylin directly write hdfs file in {{FactDistinctColumnsReducer}}, which is dangerous because the MapReduce Speculative Execution will result in more than one reducers write the same hdfs file at the same time. 
> After KYLIN-2217, I think this issue will occur with higher probability. we should  output the value by {{context.wirte}} in reducer.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)