accumulo-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Eric Newton (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (ACCUMULO-1637) Update HDFS append/sync precondition check for Hadoop 1.2
Date Wed, 16 Oct 2013 14:03:43 GMT

    [ https://issues.apache.org/jira/browse/ACCUMULO-1637?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13796813#comment-13796813
] 

Eric Newton commented on ACCUMULO-1637:
---------------------------------------

bq. We could reflect on DFSConfigKeys (handling the absence of DFS_SUPPORT_APPEND_DEFAULT
for the 1.1.x line) and then check for the presence of dfs.support.append being true in the
Hadoop conf when DFS_SUPPORT_APPEND_DEFAULT is false.

I think that's reasonable.  Thanks for digging into the version/sync details.


> Update HDFS append/sync precondition check for Hadoop 1.2
> ---------------------------------------------------------
>
>                 Key: ACCUMULO-1637
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-1637
>             Project: Accumulo
>          Issue Type: Bug
>          Components: tserver
>    Affects Versions: 1.5.0
>            Reporter: Josh Elser
>            Assignee: Josh Elser
>            Priority: Critical
>             Fix For: 1.5.1, 1.6.0
>
>
> Apache Hadoop 1.2.0 ships with the durable sync enabled by default and the support append
option marked as obsolete. Because of this, the check inside of TabletServer, meant to ensure
that the HDFS WAL can function properly, incorrectly fails as it doesn't know that dfs.durable.sync
is on by default.
> This can be worked around by specifying the old durable sync property in hdfs-site.xml:
> {noformat}
> <property>
>   <name>dfs.durable.sync</name>
>   <value>true</value>
> </property>
> {noformat}
> I'm not sure how to best way to address the differences between the newer and older versions
of Hadoop and their differing append support.
> Thanks to Carlos Mundi for pointing this out on user@a.a.o
> Using this table to track the presence of these variables and their default from hdfs/o/a/h/h/DFSConfigKeys
and from the codebase when there is no config parameter for it.
> ||Version||DFSConfigKeys.DFS_SUPPORT_APPEND_KEY||DFSConfigKeys.DFS_SUPPORT_APPEND_DEFAULT||"dfs.durable.sync"||Specific
Configuration Required||
> |0.20.205.0|defined|false|not present|yes|
> |0.23.x|defined|true|not present|no|
> |1.0.x|defined|false|not present|yes|
> |1.1.X|not present|absent|implicit "true"|no|
> |2.0.x|defined|true|not present|no|
> |2.1.x|defined|true|not present|no|
> |2.2.0|defined|true|not present|no|



--
This message was sent by Atlassian JIRA
(v6.1#6144)

Mime
View raw message