Apache Hadoop 2.7.1 Release Notes

These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.

Non-HA rollback steps have been changed. Run the rollback command on the namenode (`bin/hdfs namenode -rollback`) before starting cluster with ‘-rollback’ option using (sbin/start-dfs.sh -rollback).

Public service notice: * Every restart of a 2.6.x or 2.7.0 DN incurs a risk of unwanted block deletion. * Apply this patch if you are running a pre-2.7.1 release.

Proxy level retries will not be done on AlreadyBeingCreatedExeption for create() op.

ResourceManager will now record ResourceRequests from different attempts into different objects.