HADOOP-10423. Clarify compatibility policy document for combination of new client and old server. (Chris Nauroth via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1581116 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Karthik Kambatla 2014-03-24 23:26:34 +00:00
parent 935075121f
commit 830e367c96
2 changed files with 12 additions and 0 deletions

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@ -383,6 +383,9 @@ Release 2.4.0 - UNRELEASED
HADOOP-10015. UserGroupInformation prints out excessive warnings.
(Nicolas Liochon via szetszwo)
HADOOP-10423. Clarify compatibility policy document for combination of
new client and old server. (Chris Nauroth via kasha)
OPTIMIZATIONS
BUG FIXES

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@ -124,6 +124,15 @@ hand-in-hand to address this.
(cluster) to a later version (or vice versa). For example, a
Hadoop 2.1.0 client talking to a Hadoop 2.3.0 cluster.
* Client-Server compatibility is also required to allow users to upgrade the
client before upgrading the server (cluster). For example, a Hadoop 2.4.0
client talking to a Hadoop 2.3.0 cluster. This allows deployment of
client-side bug fixes ahead of full cluster upgrades. Note that new cluster
features invoked by new client APIs or shell commands will not be usable.
YARN applications that attempt to use new APIs (including new fields in data
structures) that have not yet deployed to the cluster can expect link
exceptions.
* Client-Server compatibility is also required to allow upgrading
individual components without upgrading others. For example,
upgrade HDFS from version 2.1.0 to 2.2.0 without upgrading MapReduce.