[jira] [Updated] (HADOOP-12041) Re-implement the underlying facilities and algorithms for Java Reed-Solomon coders

["Kai Zheng (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HADOOP-12041?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Kai Zheng updated HADOOP-12041:
-------------------------------
    Summary: Re-implement the underlying facilities and algorithms for Java Reed-Solomon coders  (was: Get rid of current GaloisField implementation and re-implement the Java Reed-Solomon algorithm)

> Re-implement the underlying facilities and algorithms for Java Reed-Solomon coders
> ----------------------------------------------------------------------------------
>
>                 Key: HADOOP-12041
>                 URL: https://issues.apache.org/jira/browse/HADOOP-12041
>             Project: Hadoop Common
>          Issue Type: Sub-task
>            Reporter: Kai Zheng
>            Assignee: Kai Zheng
>
> Currently existing Java RS coders based on {{GaloisField}} implementation have some drawbacks or limitations:
> * The decoder computes not really erased units unnecessarily (HADOOP-11871);
> * The decoder requires parity units + data units order for the inputs in the decode API (HADOOP-12040);
> * Need to support or align with native erasure coders regarding concrete coding algorithms and matrix, so Java coders and native coders can be easily swapped in/out and transparent to HDFS (HADOOP-12010);
> * It's unnecessarily flexible but incurs some overhead, as HDFS erasure coding is totally a byte based data system, we don't need to consider other symbol size instead of 256.
> This desires to re-implement the underlying facilities for the Java RS coders, getting rid of existing {{GaliosField}} from HDFS-RAID. Based on this work, Java RS coders will be re-implemented easily as well to resolve related issues.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)