Sync docs from master to gh-pages

multi/multi__programming_model.html

@@ -224,7 +224,8 @@ Consider the following example of a polled consumer:</p><pre class="programlisti
         }
     };
 }</pre><p>The <code class="literal">PollableMessageSource.poll()</code> method takes a <code class="literal">MessageHandler</code> argument (often a lambda expression, as shown here).
-It returns <code class="literal">true</code> if the message was received and successfully processed.</p><p>As with message-driven consumers, if the <code class="literal">MessageHandler</code> throws an exception, messages are published to error channels, as discussed in <span class="quote">&#8220;<span class="quote"><a class="xref" href="">???</a></span>&#8221;</span>.</p><p>Normally, the <code class="literal">poll()</code> method acknowledges the message when the <code class="literal">MessageHandler</code> exits.
+It returns <code class="literal">true</code> if the message was received and successfully processed.</p><p>As with message-driven consumers, if the <code class="literal">MessageHandler</code> throws an exception, messages are published to error channels,
+as discussed in <code class="literal"><a class="xref" href="multi__programming_model.html#spring-cloud-stream-overview-error-handling" title="6.4&nbsp;Error Handling">Section&nbsp;6.4, &#8220;Error Handling&#8221;</a></code>.</p><p>Normally, the <code class="literal">poll()</code> method acknowledges the message when the <code class="literal">MessageHandler</code> exits.
 If the method exits abnormally, the message is rejected (not re-queued), but see <a class="xref" href="multi__programming_model.html#polled-errors" title="Handling Errors">the section called &#8220;Handling Errors&#8221;</a>.
 You can override that behavior by taking responsibility for the acknowledgment, as shown in the following example:</p><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@Bean</span></em>
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> ApplicationRunner poller(PollableMessageSource dest1In, MessageChannel dest2Out) {
@@ -250,7 +251,7 @@ If the service activator throws a <code class="literal">RequeueCurrentMessageExc
 The error handling comes in two flavors:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><span class="strong"><strong>application:</strong></span> The error handling is done within the application (custom error handler).</li><li class="listitem"><span class="strong"><strong>system:</strong></span> The error handling is delegated to the binder (re-queue, DL, and others). Note that the techniques are dependent on binder implementation and the
 capability of the underlying messaging middleware.</li></ul></div><p>Spring Cloud Stream uses the <a class="link" href="https://github.com/spring-projects/spring-retry" target="_top">Spring Retry</a> library to facilitate successful message processing. See <a class="xref" href="multi__programming_model.html#_retry_template" title="6.4.3&nbsp;Retry Template">Section&nbsp;6.4.3, &#8220;Retry Template&#8221;</a> for more details.
 However, when all fails, the exceptions thrown by the message handlers are propagated back to the binder. At that point, binder invokes custom error handler or communicates
-the error back to the messaging system (re-queue, DLQ, and others).</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_application_error_handling" href="#_application_error_handling"></a>6.4.1&nbsp;Application Error Handling</h3></div></div></div><p>There are two types of application-level error handling. Errors can be handled at each binding subscription or a global handler can handle all the binding subscription errors. Let&#8217;s review the details.</p><div class="figure"><a name="d0e1506" href="#d0e1506"></a><p class="title"><b>Figure&nbsp;6.1.&nbsp;A Spring Cloud Stream Sink Application with Custom and Global Error Handlers</b></p><div class="figure-contents"><div class="mediaobject" align="center"><img src="https://raw.githubusercontent.com/spring-cloud/spring-cloud-stream/master/docs/src/main/asciidoc/images/custom_vs_global_error_channels.png" align="middle" alt="custom vs global error channels"></div></div></div><br class="figure-break"><p>For each input binding, Spring Cloud Stream creates a dedicated error channel with the following semantics <code class="literal">&lt;destinationName&gt;.errors</code>.</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Note"><tr><td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="images/note.png"></td><th align="left">Note</th></tr><tr><td align="left" valign="top"><p>The <code class="literal">&lt;destinationName&gt;</code> consists of the name of the binding (such as <code class="literal">input</code>) and the name of the group (such as <code class="literal">myGroup</code>).</p></td></tr></table></div><p>Consider the following:</p><pre class="programlisting">spring.cloud.stream.bindings.input.group=myGroup</pre><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@StreamListener(Sink.INPUT)</span></em> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-comment">// destination name 'input.myGroup'</span>
+the error back to the messaging system (re-queue, DLQ, and others).</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_application_error_handling" href="#_application_error_handling"></a>6.4.1&nbsp;Application Error Handling</h3></div></div></div><p>There are two types of application-level error handling. Errors can be handled at each binding subscription or a global handler can handle all the binding subscription errors. Let&#8217;s review the details.</p><div class="figure"><a name="d0e1507" href="#d0e1507"></a><p class="title"><b>Figure&nbsp;6.1.&nbsp;A Spring Cloud Stream Sink Application with Custom and Global Error Handlers</b></p><div class="figure-contents"><div class="mediaobject" align="center"><img src="https://raw.githubusercontent.com/spring-cloud/spring-cloud-stream/master/docs/src/main/asciidoc/images/custom_vs_global_error_channels.png" align="middle" alt="custom vs global error channels"></div></div></div><br class="figure-break"><p>For each input binding, Spring Cloud Stream creates a dedicated error channel with the following semantics <code class="literal">&lt;destinationName&gt;.errors</code>.</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Note"><tr><td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="images/note.png"></td><th align="left">Note</th></tr><tr><td align="left" valign="top"><p>The <code class="literal">&lt;destinationName&gt;</code> consists of the name of the binding (such as <code class="literal">input</code>) and the name of the group (such as <code class="literal">myGroup</code>).</p></td></tr></table></div><p>Consider the following:</p><pre class="programlisting">spring.cloud.stream.bindings.input.group=myGroup</pre><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@StreamListener(Sink.INPUT)</span></em> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-comment">// destination name 'input.myGroup'</span>
 <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">void</span> handle(Person value) {
 	<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">throw</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">new</span> RuntimeException(<span xmlns:d="http://docbook.org/ns/docbook" class="hl-string">"BOOM!"</span>);
 }