diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt index d9e8b9e291f..ac58c399fcf 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt +++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt @@ -764,6 +764,9 @@ Release 2.7.0 - UNRELEASED HDFS-7054. Make DFSOutputStream tracing more fine-grained (cmccabe) + HDFS.7849. Update documentation for enabling a new feature in rolling + upgrade ( J.Andreina via vinayakumarb ) + OPTIMIZATIONS HDFS-7454. Reduce memory footprint for AclEntries in NameNode. diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/site/xdoc/HdfsRollingUpgrade.xml b/hadoop-hdfs-project/hadoop-hdfs/src/site/xdoc/HdfsRollingUpgrade.xml index 28649a8f1a0..2ad28e110a4 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/site/xdoc/HdfsRollingUpgrade.xml +++ b/hadoop-hdfs-project/hadoop-hdfs/src/site/xdoc/HdfsRollingUpgrade.xml @@ -47,6 +47,15 @@ These two capabilities make it feasible to upgrade HDFS without incurring HDFS downtime. In order to upgrade a HDFS cluster without downtime, the cluster must be setup with HA.
++ If there is any new feature which is enabled in new software release, may not work with old software release after upgrade. + In such cases upgrade should be done by following steps. +
+Note that rolling upgrade is supported only from Hadoop-2.4.0 onwards.