[ https://issues.apache.org/jira/browse/HDFS-6840?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Andrew Wang updated HDFS-6840: ------------------------------ Status: Patch Available (was: Open) > Clients are always sent to the same datanode when read is off rack > ------------------------------------------------------------------ > > Key: HDFS-6840 > URL: https://issues.apache.org/jira/browse/HDFS-6840 > Project: Hadoop HDFS > Issue Type: Bug > Affects Versions: 2.5.0 > Reporter: Jason Lowe > Assignee: Andrew Wang > Priority: Critical > Attachments: hdfs-6840.001.patch > > > After HDFS-6268 the sorting order of block locations is deterministic for a > given block and locality level (e.g.: local, rack. off-rack), so off-rack > clients all see the same datanode for the same block. This leads to very > poor behavior in distributed cache localization and other scenarios where > many clients all want the same block data at approximately the same time. > The one datanode is crushed by the load while the other replicas only handle > local and rack-local requests. -- This message was sent by Atlassian JIRA (v6.2#6252)