This is the documentation for CDH 4.7.0.
Documentation for other versions is available at Cloudera Documentation.

Known Issues Fixed In CDH4.2.1

For a list of the upstream fixes applied in CDH4.2.1, see What's New in CDH4.2.1

Apache MapReduce

— Jobs fail in MRv2 (YARN) when run on medium or larger-sized data sets

A bug in the merge phase causes Reduce tasks to fail on YARN whenever their input data exceeds memory and must spill to disk.

Bug: MAPREDUCE-2264

Severity: High

Resolution: Fixed in CDH4.2.1

Workaround: None

Apache HBase

— With replication enabled, Region Server may abort

When Replication is enabled, a Region Server could abort during a failover of an aborted Region Server.

Bug: None

Severity: Medium

Resolution:Fixed in CDH4.2.1.

Workaround:To avoid this problem, set hbase.zookeeper.useMulti to false in the conf/hbase-site.xml, as follows:

<property>
    <name>hbase.zookeeper.useMulti</name>
    <value>false</value>
  </property>