[
https://issues.apache.org/jira/browse/ACCUMULO-884?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Sean Busbey updated ACCUMULO-884:
---------------------------------
Priority: Major (was: Minor)
The deliverables to close would be:
* Performance #s for some workload(s) as justification
* User manual addendum on configuration changes needed in HDFS and/or Accumulo
(ala [HBase's
section|http://hbase.apache.org/0.94/book.html#perf.hdfs.configs.localread])
Optional:
* logs or Monitor changes to show short circuit presence in running instance
I'm putting the priority back at Major because the performance impact on HBase
was significant.
> Take advantage of short circuit read for local files
> ----------------------------------------------------
>
> Key: ACCUMULO-884
> URL: https://issues.apache.org/jira/browse/ACCUMULO-884
> Project: Accumulo
> Issue Type: Sub-task
> Components: docs
> Reporter: Billie Rinaldi
>
> This is a new feature in hadoop 1.0.x and some versions of 0.22 and 0.23. It
> allows a client to read directly from disk instead of through a DataNode when
> the data is stored locally. Enabling it involves setting two configuration
> parameters, the first in hdfs-site.xml and the second in accumulo-site.xml.
> We should make sure this works with Accumulo and recommend it in the
> documentation.
> - dfs.block.local-path-access.user is the key in datanode configuration to
> specify the user allowed to do short circuit read.
> - dfs.client.read.shortcircuit is the key to enable short circuit read at the
> client side configuration.
> See HDFS-2246 and http://hbase.apache.org/book/perf.hdfs.configs.html for
> more information.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
