hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Todd Lipcon (JIRA)" <j...@apache.org>
Subject [jira] Updated: (HADOOP-5598) Implement a pure Java CRC32 calculator
Date Tue, 16 Jun 2009 18:37:07 GMT

     [ https://issues.apache.org/jira/browse/HADOOP-5598?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Todd Lipcon updated HADOOP-5598:
--------------------------------

    Attachment: hadoop-5598.txt

I managed to coerce Java into cooperating with int sized variables, and it's significantly
faster now. It's now about 5-10% slower than the built-in CRC for large sizes.

> Implement a pure Java CRC32 calculator
> --------------------------------------
>
>                 Key: HADOOP-5598
>                 URL: https://issues.apache.org/jira/browse/HADOOP-5598
>             Project: Hadoop Core
>          Issue Type: Improvement
>          Components: dfs
>            Reporter: Owen O'Malley
>            Assignee: Todd Lipcon
>         Attachments: crc32-results.txt, hadoop-5598-evil.txt, hadoop-5598-hybrid.txt,
hadoop-5598.txt, hadoop-5598.txt, TestCrc32Performance.java, TestCrc32Performance.java
>
>
> We've seen a reducer writing 200MB to HDFS with replication = 1 spending a long time
in crc calculation. In particular, it was spending 5 seconds in crc calculation out of a total
of 6 for the write. I suspect that it is the java-jni border that is causing us grief.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message