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HDFS-8110. Remove unsupported 'hdfs namenode -rollingUpgrade downgrade' from document. Contributed by J.Andreina.

This commit is contained in:
Akira Ajisaka 2015-04-24 20:32:26 +09:00
parent c8d72907ff
commit 91b97c21c9
2 changed files with 6 additions and 23 deletions
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3
hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
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@ -315,6 +315,9 @@ Trunk (Unreleased)
HDFS-4681. TestBlocksWithNotEnoughRacks#testCorruptBlockRereplicatedAcrossRacks
fails using IBM java (Ayappan via aw)
HDFS-8110. Remove unsupported 'hdfs namenode -rollingUpgrade downgrade'
from document. (J.Andreina via aajisaka)
Release 2.8.0 - UNRELEASED
INCOMPATIBLE CHANGES

26
hadoop-hdfs-project/hadoop-hdfs/src/site/xdoc/HdfsRollingUpgrade.xml
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@ -190,14 +190,12 @@
only if both the namenode layout version and the datenode layout version
are not changed between these two releases.
</p>
<subsection name="Downgrade without Downtime" id="DowngradeWithoutDowntime">
<p>
In a HA cluster,
when a rolling upgrade from an old software release to a new software release is in progress,
it is possible to downgrade, in a rolling fashion, the upgraded machines back to the old software release.
Same as before, suppose <em>NN1</em> and <em>NN2</em> are respectively in active and standby states.
Below are the steps for rolling downgrade:
Below are the steps for rolling downgrade without downtime:
</p>
<ol>
<li>Downgrade <em>DNs</em><ol>
@ -214,16 +212,12 @@
</ol></li>
<li>Downgrade Active and Standby <em>NNs</em><ol>
<li>Shutdown and downgrade <em>NN2</em>.</li>
<li>Start <em>NN2</em> as standby normally. (Note that it is incorrect to use the
"<a href="#namenode_-rollingUpgrade"><code>-rollingUpgrade downgrade</code></a>"
option here.)
<li>Start <em>NN2</em> as standby normally.
</li>
<li>Failover from <em>NN1</em> to <em>NN2</em>
so that <em>NN2</em> becomes active and <em>NN1</em> becomes standby.</li>
<li>Shutdown and upgrade <em>NN1</em>.</li>
<li>Start <em>NN1</em> as standby normally. (Note that it is incorrect to use the
"<a href="#namenode_-rollingUpgrade"><code>-rollingUpgrade downgrade</code></a>"
option here.)
<li>Start <em>NN1</em> as standby normally.
</li>
</ol></li>
<li>Finalize Rolling Downgrade<ul>
@ -236,20 +230,6 @@
since protocols may be changed in a backward compatible manner but not forward compatible,
i.e. old datanodes can talk to the new namenodes but not vice versa.
</p>
</subsection>
<subsection name="Downgrade with Downtime" id="DowngradeWithDowntime">
<p>
Administrator may choose to first shutdown the cluster and then downgrade it.
The following are the steps:
</p>
<ol>
<li>Shutdown all <em>NNs</em> and <em>DNs</em>.</li>
<li>Restore the pre-upgrade release in all machines.</li>
<li>Start <em>NNs</em> with the
"<a href="#namenode_-rollingUpgrade"><code>-rollingUpgrade downgrade</code></a>" option.</li>
<li>Start <em>DNs</em> normally.</li>
</ol>
</subsection>
</section>
<section name="Rollback" id="Rollback">