hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hudson (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-2834) ByteBuffer-based read API for DFSInputStream
Date Thu, 22 Mar 2012 14:00:24 GMT

    [ https://issues.apache.org/jira/browse/HDFS-2834?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13235582#comment-13235582
] 

Hudson commented on HDFS-2834:
------------------------------

Integrated in Hadoop-Mapreduce-trunk #1027 (See [https://builds.apache.org/job/Hadoop-Mapreduce-trunk/1027/])
    HDFS-2834. Add a ByteBuffer-based read API to DFSInputStream. Contributed by Henry Robinson.
(Revision 1303474)

     Result = SUCCESS
todd : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1303474
Files : 
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/BlockReader.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/BlockReaderLocal.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSInputStream.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/RemoteBlockReader.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/RemoteBlockReader2.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/BlockReaderTestUtil.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestBlockReaderLocal.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestParallelRead.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestParallelReadUtil.java
* /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestShortCircuitLocalRead.java

                
> ByteBuffer-based read API for DFSInputStream
> --------------------------------------------
>
>                 Key: HDFS-2834
>                 URL: https://issues.apache.org/jira/browse/HDFS-2834
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>            Reporter: Henry Robinson
>            Assignee: Henry Robinson
>             Fix For: 0.24.0
>
>         Attachments: HDFS-2834-no-common.patch, HDFS-2834.10.patch, HDFS-2834.11.patch,
HDFS-2834.3.patch, HDFS-2834.4.patch, HDFS-2834.5.patch, HDFS-2834.6.patch, HDFS-2834.7.patch,
HDFS-2834.8.patch, HDFS-2834.9.patch, HDFS-2834.patch, HDFS-2834.patch, hdfs-2834-libhdfs-benchmark.png
>
>
> The {{DFSInputStream}} read-path always copies bytes into a JVM-allocated {{byte[]}}.
Although for many clients this is desired behaviour, in certain situations, such as native-reads
through libhdfs, this imposes an extra copy penalty since the {{byte[]}} needs to be copied
out again into a natively readable memory area. 
> For these cases, it would be preferable to allow the client to supply its own buffer,
wrapped in a {{ByteBuffer}}, to avoid that final copy overhead. 

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message