[jira] [Comment Edited] (ACCUMULO-1947) dfs.datanode.synconclose check is lacking

["Josh Elser (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ACCUMULO-1947?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13836836#comment-13836836 ] 

Josh Elser edited comment on ACCUMULO-1947 at 12/2/13 8:10 PM:
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Looks like the current check would incorrectly not warn users on >=hadoop-1.1.1 and 1.2 (the CreateFlag class does not exist, yet the option for DFS_DATANODE_SYNCONCLOSE does exist). Hadoop-1.0.x and Hadoop-1.1.0 don't have the variable defined.


was (Author: elserj):
Looks like the current check would incorrectly not warn users on hadoop-1.1 and 1.2 (the CreateFlag class does not exist, yet the option for DFS_DATANODE_SYNCONCLOSE does exist).

> dfs.datanode.synconclose check is lacking
> -----------------------------------------
>
>                 Key: ACCUMULO-1947
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-1947
>             Project: Accumulo
>          Issue Type: Bug
>            Reporter: Josh Elser
>            Assignee: Josh Elser
>            Priority: Blocker
>             Fix For: 1.5.1, 1.6.0
>
>
> The dfs configuration checks we now perform to support hdfs WALs includes a check for dfs.datanode.synconclose which informs the datanode to flush to disk when a file is closed instead of lazily writing the block (very important in the case of power failure).
> Looking at the actual check, it performs reflection on a CreateFlag class. In Apache Hadoop 1.2.1, this class doesn't exist yet the option for dfs.datanode.synconclose does exist. We should likely just reflect on the constant DFSConfigKeys.DFS_DATANODE_SYNCONCLOSE_KEY or DFSConfigKeys.DFS_DATANODE_SYNCONCLOSE_DEFAULT to determine if that option is present.



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