[jira] [Updated] (MAPREDUCE-4827) Increase hash quality of HashPartitioner
[ https://issues.apache.org/jira/browse/MAPREDUCE-4827?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Radim Kolar updated MAPREDUCE-4827: --- Resolution: Won't Fix Status: Resolved (was: Patch Available) Patch rejected for backward compatibility reasons. Increase hash quality of HashPartitioner Key: MAPREDUCE-4827 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4827 Project: Hadoop Map/Reduce Issue Type: Improvement Reporter: Radim Kolar Attachments: betterhash1.txt, betterhash2.txt hash partitioner is using object.hashCode() for splitting keys into partitions. This results in bad distributions because hashCode() quality is poor. These hashCode() functions are sometimes written by hand (very poor quality) and sometimes generated from by commons lang code (poor quality). Applying some transformation on top of hashCode() provides better distribution. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Updated] (MAPREDUCE-4827) Increase hash quality of HashPartitioner
[ https://issues.apache.org/jira/browse/MAPREDUCE-4827?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Radim Kolar updated MAPREDUCE-4827: --- Attachment: betterhash2.txt change it for old mapred api as well Increase hash quality of HashPartitioner Key: MAPREDUCE-4827 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4827 Project: Hadoop Map/Reduce Issue Type: Improvement Reporter: Radim Kolar Attachments: betterhash1.txt, betterhash2.txt hash partitioner is using object.hashCode() for splitting keys into partitions. This results in bad distributions because hashCode() quality is poor. These hashCode() functions are sometimes written by hand (very poor quality) and sometimes generated from by commons lang code (poor quality). Applying some transformation on top of hashCode() provides better distribution. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Updated] (MAPREDUCE-4827) Increase hash quality of HashPartitioner
[ https://issues.apache.org/jira/browse/MAPREDUCE-4827?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Radim Kolar updated MAPREDUCE-4827: --- Status: Patch Available (was: Open) Increase hash quality of HashPartitioner Key: MAPREDUCE-4827 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4827 Project: Hadoop Map/Reduce Issue Type: Improvement Reporter: Radim Kolar Attachments: betterhash1.txt hash partitioner is using object.hashCode() for splitting keys into partitions. This results in bad distributions because hashCode() quality is poor. These hashCode() functions are sometimes written by hand (very poor quality) and sometimes generated from by commons lang code (poor quality). Applying some transformation on top of hashCode() provides better distribution. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Updated] (MAPREDUCE-4827) Increase hash quality of HashPartitioner
[ https://issues.apache.org/jira/browse/MAPREDUCE-4827?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Radim Kolar updated MAPREDUCE-4827: --- Attachment: betterhash1.txt Increase hash quality of HashPartitioner Key: MAPREDUCE-4827 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4827 Project: Hadoop Map/Reduce Issue Type: Improvement Reporter: Radim Kolar Attachments: betterhash1.txt hash partitioner is using object.hashCode() for splitting keys into partitions. This results in bad distributions because hashCode() quality is poor. These hashCode() functions are sometimes written by hand (very poor quality) and sometimes generated from by commons lang code (poor quality). Applying some transformation on top of hashCode() provides better distribution. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
