MINOR; Update upgrade documentation for 3.3 (#12550)

docs/documentation.html

@@ -33,7 +33,7 @@
     <!--//#include virtual="../includes/_docs_banner.htm" -->
     
     <h1>Documentation</h1>
-    <h3>Kafka 3.2 Documentation</h3>
+    <h3>Kafka 3.3 Documentation</h3>
     Prior releases: <a href="/07/documentation.html">0.7.x</a>, 
                     <a href="/08/documentation.html">0.8.0</a>, 
                     <a href="/081/documentation.html">0.8.1.X</a>, 
@@ -56,6 +56,7 @@
                     <a href="/28/documentation.html">2.8.X</a>,
                     <a href="/30/documentation.html">3.0.X</a>.
                     <a href="/31/documentation.html">3.1.X</a>.
+                    <a href="/32/documentation.html">3.2.X</a>.
 
    <h2 class="anchor-heading"><a id="gettingStarted" class="anchor-link"></a><a href="#gettingStarted">1. Getting Started</a></h2>
       <h3 class="anchor-heading"><a id="introduction" class="anchor-link"></a><a href="#introduction">1.1 Introduction</a></h3>

docs/upgrade.html

@@ -19,6 +19,48 @@
 
 <script id="upgrade-template" type="text/x-handlebars-template">
 
+<h4><a id="upgrade_3_3_0" href="#upgrade_3_3_0">Upgrading to 3.3.0 from any version 0.8.x through 3.2.x</a></h4>
+
+<p><b>If you are upgrading from a version prior to 2.1.x, please see the note below about the change to the schema used to store consumer offsets.
+    Once you have changed the inter.broker.protocol.version to the latest version, it will not be possible to downgrade to a version prior to 2.1.</b></p>
+
+<p><b>For a rolling upgrade:</b></p>
+
+<ol>
+    <li>Update server.properties on all brokers and add the following properties. CURRENT_KAFKA_VERSION refers to the version you
+        are upgrading from. CURRENT_MESSAGE_FORMAT_VERSION refers to the message format version currently in use. If you have previously
+        overridden the message format version, you should keep its current value. Alternatively, if you are upgrading from a version prior
+        to 0.11.0.x, then CURRENT_MESSAGE_FORMAT_VERSION should be set to match CURRENT_KAFKA_VERSION.
+        <ul>
+            <li>inter.broker.protocol.version=CURRENT_KAFKA_VERSION (e.g. <code>3.2</code>, <code>3.1</code>, etc.)</li>
+            <li>log.message.format.version=CURRENT_MESSAGE_FORMAT_VERSION  (See <a href="#upgrade_10_performance_impact">potential performance impact
+                following the upgrade</a> for the details on what this configuration does.)</li>
+        </ul>
+        If you are upgrading from version 0.11.0.x or above, and you have not overridden the message format, then you only need to override
+        the inter-broker protocol version.
+        <ul>
+            <li>inter.broker.protocol.version=CURRENT_KAFKA_VERSION (e.g. <code>3.2</code>, <code>3.1</code>, etc.)</li>
+        </ul>
+    </li>
+    <li>Upgrade the brokers one at a time: shut down the broker, update the code, and restart it. Once you have done so, the
+        brokers will be running the latest version and you can verify that the cluster's behavior and performance meets expectations.
+        It is still possible to downgrade at this point if there are any problems.
+    </li>
+    <li>Once the cluster's behavior and performance has been verified, bump the protocol version by editing
+        <code>inter.broker.protocol.version</code> and setting it to <code>3.3</code>.
+    </li>
+    <li>Restart the brokers one by one for the new protocol version to take effect. Once the brokers begin using the latest
+        protocol version, it will no longer be possible to downgrade the cluster to an older version.
+    </li>
+    <li>If you have overridden the message format version as instructed above, then you need to do one more rolling restart to
+        upgrade it to its latest version. Once all (or most) consumers have been upgraded to 0.11.0 or later,
+        change log.message.format.version to 3.3 on each broker and restart them one by one. Note that the older Scala clients,
+        which are no longer maintained, do not support the message format introduced in 0.11, so to avoid conversion costs
+        (or to take advantage of <a href="#upgrade_11_exactly_once_semantics">exactly once semantics</a>),
+        the newer Java clients must be used.
+    </li>
+</ol>
+
 <h5><a id="upgrade_330_notable" href="#upgrade_330_notable">Notable changes in 3.3.0</a></h5>
     <ul>
         <li>Introduced a new API <code>addMetricIfAbsent</code> to <code>Metrics</code> which would create a new Metric if not existing or return the same metric