camel-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From build...@apache.org
Subject svn commit: r957787 [2/2] - in /websites/production/camel/content: book-component-appendix.html book-in-one-page.html cache/main.pageCache seda.html
Date Fri, 10 Jul 2015 14:19:50 GMT
Modified: websites/production/camel/content/seda.html
==============================================================================
--- websites/production/camel/content/seda.html (original)
+++ websites/production/camel/content/seda.html Fri Jul 10 14:19:50 2015
@@ -87,40 +87,39 @@
         <tr>
         <td valign="top" width="100%">
 <div class="wiki-content maincontent"><h2 id="SEDA-SEDAComponent">SEDA Component</h2><p>The
<strong>seda:</strong> component provides asynchronous <a shape="rect" class="external-link"
href="http://www.eecs.harvard.edu/~mdw/proj/seda/" rel="nofollow">SEDA</a> behavior,
so that messages are exchanged on a <a shape="rect" class="external-link" href="http://java.sun.com/j2se/1.5.0/docs/api/java/util/concurrent/BlockingQueue.html"
rel="nofollow">BlockingQueue</a> and consumers are invoked in a separate thread from
the producer.</p><p>Note that queues are only visible within a <em>single</em>
<a shape="rect" href="camelcontext.html">CamelContext</a>. If you want to communicate
across <code>CamelContext</code> instances (for example, communicating between
Web applications), see the <a shape="rect" href="vm.html">VM</a> component.</p><p>This
component does not implement any kind of persistence or recovery, if the VM terminates while
messages are yet to be processed. If you need persistence
 , reliability or distributed SEDA, try using either <a shape="rect" href="jms.html">JMS</a>
or <a shape="rect" href="activemq.html">ActiveMQ</a>.</p><div class="confluence-information-macro
confluence-information-macro-tip"><p class="title">Synchronous</p><span
class="aui-icon aui-icon-small aui-iconfont-approve confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>The <a shape="rect" href="direct.html">Direct</a>
component provides synchronous invocation of any consumers when a producer sends a message
exchange.</p></div></div><h3 id="SEDA-URIformat">URI format</h3><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent
pdl">
-<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">seda:someName[?options]
-</pre>
-</div></div><p>Where <strong>someName</strong> can be any string
that uniquely identifies the endpoint within the current <a shape="rect" href="camelcontext.html">CamelContext</a>.</p><p>You
can append query options to the URI in the following format: <code>?option=value&amp;option=value&amp;&#8230;</code></p><h3
id="SEDA-Options">Options</h3><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th
colspan="1" rowspan="1" class="confluenceTh"><p> Name </p></th><th
colspan="1" rowspan="1" class="confluenceTh"><p> Since </p></th><th
colspan="1" rowspan="1" class="confluenceTh"><p> Default </p></th><th
colspan="1" rowspan="1" class="confluenceTh"><p> Description </p></th></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> <code>size</code> </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>&#160;</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>&#160;</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> The maximum capacity of the SED
 A queue (i.e., the number of messages it can hold). The default value in Camel 2.2 or older
is <code>1000</code>. From Camel 2.3 onwards, the size is unbounded by default.
<strong>Notice:</strong> Mind if you use this option, then its the first endpoint
being created with the queue name, that determines the size. To make sure all endpoints use
same size, then configure the size option on all of them, or the first endpoint being created.
From <strong>Camel 2.11</strong> onwards, a validation is taken place to ensure
if using mixed queue sizes for the same queue name, Camel would detect this and fail creating
the endpoint. </p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>
<code>concurrentConsumers</code> </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>&#160;</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> <code>1</code> </p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p> Number of concurrent threads processing exchanges.
</p></t
 d></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>
<code>waitForTaskToComplete</code> </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>&#160;</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> <code>IfReplyExpected</code> </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> Option to specify whether the caller
should wait for the async task to complete or not before continuing. The following three options
are supported: <code>Always</code>, <code>Never</code> or <code>IfReplyExpected</code>.
The first two values are self-explanatory. The last value, <code>IfReplyExpected</code>,
will only wait if the message is <a shape="rect" href="request-reply.html">Request Reply</a>
based. The default option is <code>IfReplyExpected</code>. See more information
about <a shape="rect" href="async.html">Async</a> messaging. </p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> <code>timeout</code>
</p></td><td colspan="1" rowspan="1" clas
 s="confluenceTd"><p>&#160;</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> <code>30000</code> </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> Timeout (in milliseconds) before
a SEDA producer will stop waiting for an asynchronous task to complete. See <code>waitForTaskToComplete</code>
and <a shape="rect" href="async.html">Async</a> for more details. In <strong>Camel
2.2</strong> you can now disable timeout by using 0 or a negative value. </p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> <code>multipleConsumers</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <strong>2.2</strong>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <code>false</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> Specifies
whether multiple consumers are allowed. If enabled, you can use <a shape="rect" href="seda.html">SEDA</a>
for <a shape="rect" class="external-link" href="http://en.wikipedia.org/wiki/Publish
 %E2%80%93subscribe_pattern" rel="nofollow">Publish-Subscribe</a> messaging. That
is, you can send a message to the SEDA queue and have each consumer receive a copy of the
message. When enabled, this option should be specified on every consumer endpoint. </p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> <code>limitConcurrentConsumers</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <strong>2.3</strong>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <code>true</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> Whether
to limit the number of <code>concurrentConsumers</code> to the maximum of <code>500</code>.
By default, an exception will be thrown if a SEDA endpoint is configured with a greater number.
You can disable that check by turning this option off. </p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> <code>blockWhenFull</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p
 > <strong>2.9</strong> </p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p> <code>false</code> </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> Whether a thread that sends messages
to a full SEDA queue will block until the queue's capacity is no longer exhausted.  By default,
an exception will be thrown stating that the queue is full. By enabling this option, the calling
thread will instead block and wait until the message can be accepted. </p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> <code>queueSize</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <strong>2.9</strong>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>&#160;</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> <strong>Component only:</strong>
The maximum default size (capacity of the number of messages it can hold) of the SEDA queue.
This option is used if <code>size</code> is not in use. </p></td></tr><tr><td
colspan="1" rowspan="
 1" class="confluenceTd"><p> <code>pollTimeout</code> </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> <strong>2.9.3</strong>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <code>1000</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <em>Consumer
only</em> &#8211; The timeout used when polling. When a timeout occurs, the consumer
can check whether it is allowed to continue running. Setting a lower value allows the consumer
to react more quickly upon shutdown. </p></td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p> <code>purgeWhenStopping</code> </p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p> <strong>2.11.1</strong>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <code>false</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> Whether
to purge the task queue when stopping the consumer/route. This allows to stop faster, as any
pending messages on the queue is discarded. </p></td></
 tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p> <code>queue</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <strong>2.12.0</strong>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> null
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> Define
the queue instance which will be used by seda endpoint </p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> <code>queueFactory</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <strong>2.12.0</strong>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> null
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> Define
the QueueFactory which could create the queue for the seda endpoint </p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p> <code>failIfNoConsumers</code>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> <strong>2.12.0</strong>
</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> fals
 e </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> Whether
the producer should fail by throwing an exception, when sending to a SEDA queue with no active
consumers. </p></td></tr></tbody></table></div>
-<h3 id="SEDA-ChoosingBlockingQueueimplementation">Choosing BlockingQueue implementation</h3><p><strong>Available
as of Camel 2.12</strong></p><p>By default, the SEDA component always intantiates
LinkedBlockingQueue, but you can use different implementation, you can reference your own
BlockingQueue implementation, in this case the size option is not used</p><div class="code
panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">&lt;bean
id="arrayQueue" class="java.util.ArrayBlockingQueue"&gt;
-&lt;constructor-arg index="0" value="10" &gt;&lt;!-- size --&gt;
-&lt;constructor-arg index="1" value="true" &gt;&lt;!-- fairness --&gt;
+<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[seda:someName[?options]
+]]></script>
+</div></div><p>Where <strong>someName</strong> can be any string
that uniquely identifies the endpoint within the current <a shape="rect" href="camelcontext.html">CamelContext</a>.</p><p>You
can append query options to the URI in the following format: <code>?option=value&amp;option=value&amp;&#8230;</code></p><h3
id="SEDA-Options">Options</h3><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th
colspan="1" rowspan="1" class="confluenceTh"><p>Name</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>Since</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>Default</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>Description</p></th></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>size</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>&#160;</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>&#160;</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>The maximum capacity of the SEDA
queue (i.
 e., the number of messages it can hold). The default value in Camel 2.2 or older is <code>1000</code>.
From Camel 2.3 onwards, the size is unbounded by default. <strong>Notice:</strong>
Mind if you use this option, then its the first endpoint being created with the queue name,
that determines the size. To make sure all endpoints use same size, then configure the size
option on all of them, or the first endpoint being created. From <strong>Camel 2.11</strong>
onwards, a validation is taken place to ensure if using mixed queue sizes for the same queue
name, Camel would detect this and fail creating the endpoint.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>concurrentConsumers</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>&#160;</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>1</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Number of concurrent threads processing
exchanges.</p></td></tr><tr><td col
 span="1" rowspan="1" class="confluenceTd"><p><code>waitForTaskToComplete</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>&#160;</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>IfReplyExpected</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Option to specify whether the caller
should wait for the async task to complete or not before continuing. The following three options
are supported: <code>Always</code>, <code>Never</code> or <code>IfReplyExpected</code>.
The first two values are self-explanatory. The last value, <code>IfReplyExpected</code>,
will only wait if the message is <a shape="rect" href="request-reply.html">Request Reply</a>
based. The default option is <code>IfReplyExpected</code>. See more information
about <a shape="rect" href="async.html">Async</a> messaging.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>timeout</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>&#160;
 </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><code>30000</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Timeout (in milliseconds) before
a SEDA producer will stop waiting for an asynchronous task to complete. See <code>waitForTaskToComplete</code>
and <a shape="rect" href="async.html">Async</a> for more details. In <strong>Camel
2.2</strong> you can now disable timeout by using 0 or a negative value.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>multipleConsumers</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.2</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Specifies whether multiple consumers
are allowed. If enabled, you can use <a shape="rect" href="seda.html">SEDA</a>
for <a shape="rect" class="external-link" href="http://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern"
rel="nofo
 llow">Publish-Subscribe</a> messaging. That is, you can send a message to the SEDA
queue and have each consumer receive a copy of the message. When enabled, this option should
be specified on every consumer endpoint.</p></td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p><code>limitConcurrentConsumers</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.3</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>true</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Whether to limit the number of <code>concurrentConsumers</code>
to the maximum of <code>500</code>. By default, an exception will be thrown if
a SEDA endpoint is configured with a greater number. You can disable that check by turning
this option off.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>blockWhenFull</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.9</strong></p></td><td
colspan="1" ro
 wspan="1" class="confluenceTd"><p><code>false</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Whether a thread that sends messages
to a full SEDA queue will block until the queue's capacity is no longer exhausted. By default,
an exception will be thrown stating that the queue is full. By enabling this option, the calling
thread will instead block and wait until the message can be accepted.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>queueSize</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.9</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>&#160;</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><strong>Component only:</strong>
The maximum default size (capacity of the number of messages it can hold) of the SEDA queue.
This option is used if <code>size</code> is not in use.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>pollTimeout</code></p></td><
 td colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.9.3</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>1000</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><em>Consumer only</em>
&#8211; The timeout used when polling. When a timeout occurs, the consumer can check whether
it is allowed to continue running. Setting a lower value allows the consumer to react more
quickly upon shutdown.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p><code>purgeWhenStopping</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.11.1</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><code>false</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Whether to purge the task queue when
stopping the consumer/route. This allows to stop faster, as any pending messages on the queue
is discarded.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>queue</code>
 </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.12.0</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>null</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Define the queue instance which will be used
by seda endpoint</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p><code>queueFactory</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.12.0</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>null</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Define the QueueFactory which could create the
queue for the seda endpoint</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p><code>failIfNoConsumers</code></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p><strong>2.12.0</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>false</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Whether the producer should fail
by 
 throwing an exception, when sending to a SEDA queue with no active consumers.</p><p>Only
one of the options discardIfNoConsumers and failIfNoConsumers can be enabled at the same time.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><code>discardIfNoConsumers</code></td><td
colspan="1" rowspan="1" class="confluenceTd"><strong>2.16</strong></td><td
colspan="1" rowspan="1" class="confluenceTd"><code>false</code></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Whether the producer should discard
the message (do not add the message to the queue), when sending to a SEDA queue with no active
consumers.</p><p><span>Only one of the options discardIfNoConsumers and
failIfNoConsumers can be enabled at the same time.</span></p></td></tr></tbody></table></div><h3
id="SEDA-ChoosingBlockingQueueimplementation">Choosing BlockingQueue implementation</h3><p><strong>Available
as of Camel 2.12</strong></p><p>By default, the SEDA component always intantiates
LinkedBlockingQueue
 , but you can use different implementation, you can reference your own BlockingQueue implementation,
in this case the size option is not used</p><div class="code panel pdl" style="border-width:
1px;"><div class="codeContent panelContent pdl">
+<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[&lt;bean
id=&quot;arrayQueue&quot; class=&quot;java.util.ArrayBlockingQueue&quot;&gt;
+&lt;constructor-arg index=&quot;0&quot; value=&quot;10&quot; &gt;&lt;!--
size --&gt;
+&lt;constructor-arg index=&quot;1&quot; value=&quot;true&quot; &gt;&lt;!--
fairness --&gt;
 &lt;/bean&gt;
 &lt;!-- ... and later --&gt;
 &lt;from&gt;seda:array?queue=#arrayQueue&lt;/from&gt;
-</pre>
+]]></script>
 </div></div><p>Or you can reference a BlockingQueueFactory implementation,
3 implementations are provided LinkedBlockingQueueFactory, ArrayBlockingQueueFactory and PriorityBlockingQueueFactory:</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent
pdl">
-<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">&lt;bean
id="priorityQueueFactory" class="org.apache.camel.component.seda.PriorityBlockingQueueFactory"&gt;
-&lt;property name="comparator"&gt;
-&lt;bean class="org.apache.camel.demo.MyExchangeComparator" /&gt;
+<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[&lt;bean
id=&quot;priorityQueueFactory&quot; class=&quot;org.apache.camel.component.seda.PriorityBlockingQueueFactory&quot;&gt;
+&lt;property name=&quot;comparator&quot;&gt;
+&lt;bean class=&quot;org.apache.camel.demo.MyExchangeComparator&quot; /&gt;
 &lt;/property&gt;
 &lt;/bean&gt;
 &lt;!-- ... and later --&gt;
 &lt;from&gt;seda:priority?queueFactory=#priorityQueueFactory&amp;size=100&lt;/from&gt;
-</pre>
+]]></script>
 </div></div><h3 id="SEDA-UseofRequestReply">Use of Request Reply</h3><p>The
<a shape="rect" href="seda.html">SEDA</a> component supports using <a shape="rect"
href="request-reply.html">Request Reply</a>, where the caller will wait for the <a
shape="rect" href="async.html">Async</a> route to complete. For instance:</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent
pdl">
-<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">from("mina:tcp://0.0.0.0:9876?textline=true&amp;sync=true").to("seda:input");
+<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[from(&quot;mina:tcp://0.0.0.0:9876?textline=true&amp;sync=true&quot;).to(&quot;seda:input&quot;);
 
-from("seda:input").to("bean:processInput").to("bean:createResponse");
-</pre>
+from(&quot;seda:input&quot;).to(&quot;bean:processInput&quot;).to(&quot;bean:createResponse&quot;);
+]]></script>
 </div></div><p>In the route above, we have a TCP listener on port 9876
that accepts incoming requests. The request is routed to the <code>seda:input</code>
queue. As it is a <a shape="rect" href="request-reply.html">Request Reply</a>
message, we wait for the response. When the consumer on the <code>seda:input</code>
queue is complete, it copies the response to the original message response.</p><div
class="confluence-information-macro confluence-information-macro-note"><p class="title">until
2.2: Works only with 2 endpoints</p><span class="aui-icon aui-icon-small aui-iconfont-warning
confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>Using
<a shape="rect" href="request-reply.html">Request Reply</a> over <a shape="rect"
href="seda.html">SEDA</a> or <a shape="rect" href="vm.html">VM</a> only
works with 2 endpoints. You <strong>cannot</strong> chain endpoints by sending
to A -&gt; B -&gt; C etc. Only between A -&gt; B. The reason is the implement
 ation logic is fairly simple. To support 3+ endpoints makes the logic much more complex to
handle ordering and notification between the waiting threads properly.</p><p>This
has been improved in <strong>Camel 2.3</strong> onwards, which allows you to chain
as many endpoints as you like.</p></div></div><h3 id="SEDA-Concurrentconsumers">Concurrent
consumers</h3><p>By default, the SEDA endpoint uses a single consumer thread,
but you can configure it to use concurrent consumer threads. So instead of thread pools you
can use:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
-<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">from("seda:stageName?concurrentConsumers=5").process(...)
-</pre>
+<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[from(&quot;seda:stageName?concurrentConsumers=5&quot;).process(...)
+]]></script>
 </div></div><p>As for the difference between the two, note a <em>thread
pool</em> can increase/shrink dynamically at runtime depending on load, whereas the
number of concurrent consumers is always fixed.</p><h3 id="SEDA-Threadpools">Thread
pools</h3><p>Be aware that adding a thread pool to a SEDA endpoint by doing something
like:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
-<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">from("seda:stageName").thread(5).process(...)
-</pre>
+<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[from(&quot;seda:stageName&quot;).thread(5).process(...)
+]]></script>
 </div></div><p>Can wind up with two <code>BlockQueues</code>:
one from the SEDA endpoint, and one from the workqueue of the thread pool, which may not be
what you want. Instead, you might wish to configure a <a shape="rect" href="direct.html">Direct</a>
endpoint with a thread pool, which can process messages both synchronously and asynchronously.
For example:</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeContent panelContent pdl">
-<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">from("direct:stageName").thread(5).process(...)
-</pre>
+<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[from(&quot;direct:stageName&quot;).thread(5).process(...)
+]]></script>
 </div></div><p>You can also directly configure number of threads that process
messages on a SEDA endpoint using the <code>concurrentConsumers</code> option.</p><h3
id="SEDA-Sample">Sample</h3><p>In the route below we use the SEDA queue to
send the request to this async queue to be able to send a fire-and-forget message for further
processing in another thread, and return a constant reply in this thread to the original caller.</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent
pdl">
 <script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
 public void configure() throws Exception {
@@ -133,12 +132,12 @@ public void configure() throws Exception
     from(&quot;seda:next&quot;).to(&quot;mock:result&quot;);
 }
 ]]></script>
-</div></div><p>Here we send a Hello World message and expects the reply
to be OK.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
+</div></div>Here we send a Hello World message and expects the reply to be OK.<div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent
pdl">
 <script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
 Object out = template.requestBody(&quot;direct:start&quot;, &quot;Hello World&quot;);
 assertEquals(&quot;OK&quot;, out);
 ]]></script>
-</div></div><p>The "Hello World" message will be consumed from the SEDA
queue from another thread for further processing. Since this is from a unit test, it will
be sent to a <code>mock</code> endpoint where we can do assertions in the unit
test.</p><h3 id="SEDA-UsingmultipleConsumers">Using multipleConsumers</h3><p><strong>Available
as of Camel 2.2</strong></p><p>In this example we have defined two consumers
and registered them as spring beans.</p><div class="code panel pdl" style="border-width:
1px;"><div class="codeContent panelContent pdl">
+</div></div>The "Hello World" message will be consumed from the SEDA queue from
another thread for further processing. Since this is from a unit test, it will be sent to
a <code>mock</code> endpoint where we can do assertions in the unit test.<h3
id="SEDA-UsingmultipleConsumers">Using multipleConsumers</h3><p><strong>Available
as of Camel 2.2</strong></p><p>In this example we have defined two consumers
and registered them as spring beans.</p><div class="code panel pdl" style="border-width:
1px;"><div class="codeContent panelContent pdl">
 <script class="brush: xml; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
 &lt;!-- define the consumers as spring beans --&gt;
 &lt;bean id=&quot;consumer1&quot; class=&quot;org.apache.camel.spring.example.FooEventConsumer&quot;/&gt;
@@ -150,7 +149,7 @@ assertEquals(&quot;OK&quot;, out);
     &lt;endpoint id=&quot;foo&quot; uri=&quot;seda:foo?multipleConsumers=true&quot;/&gt;
 &lt;/camelContext&gt;
 ]]></script>
-</div></div><p>Since we have specified <strong>multipleConsumers=true</strong>
on the seda foo endpoint we can have those two consumers receive their own copy of the message
as a kind of pub-sub style messaging.</p><p>As the beans are part of an unit test
they simply send the message to a mock endpoint, but notice how we can use @Consume to consume
from the seda queue.</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeContent panelContent pdl">
+</div></div>Since we have specified <strong>multipleConsumers=true</strong>
on the seda foo endpoint we can have those two consumers receive their own copy of the message
as a kind of pub-sub style messaging.<p>As the beans are part of an unit test they simply
send the message to a mock endpoint, but notice how we can use @Consume to consume from the
seda queue.</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeContent panelContent pdl">
 <script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[
 public class FooEventConsumer {
 
@@ -165,9 +164,9 @@ public class FooEventConsumer {
 }
 ]]></script>
 </div></div><h3 id="SEDA-Extractingqueueinformation.">Extracting queue
information.</h3><p>If needed, information such as queue size, etc. can be obtained
without using JMX in this fashion:</p><div class="code panel pdl" style="border-width:
1px;"><div class="codeContent panelContent pdl">
-<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">SedaEndpoint
seda = context.getEndpoint("seda:xxxx");
+<script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[SedaEndpoint
seda = context.getEndpoint(&quot;seda:xxxx&quot;);
 int size = seda.getExchanges().size();
-</pre>
+]]></script>
 </div></div><p></p><h3 id="SEDA-SeeAlso">See Also</h3>
 <ul><li><a shape="rect" href="configuring-camel.html">Configuring Camel</a></li><li><a
shape="rect" href="component.html">Component</a></li><li><a shape="rect"
href="endpoint.html">Endpoint</a></li><li><a shape="rect" href="getting-started.html">Getting
Started</a></li></ul><ul class="alternate"><li><a shape="rect"
href="vm.html">VM</a></li><li><a shape="rect" href="disruptor.html">Disruptor</a></li><li><a
shape="rect" href="direct.html">Direct</a></li><li><a shape="rect"
href="async.html">Async</a></li></ul></div>
         </td>
@@ -175,7 +174,7 @@ int size = seda.getExchanges().size();
           <div class="navigation">
             <div class="navigation_top">
                 <!-- NavigationBar -->
-<div class="navigation_bottom" id="navigation_bottom"><h3 id="Navigation-Overviewhttps://cwiki.apache.org/confluence/pages/viewpage.action?pageId=49132"><a
shape="rect" href="overview.html">Overview</a></h3><ul class="alternate"><li><a
shape="rect" href="index.html">Home</a></li><li><a shape="rect" href="download.html">Download</a></li><li><a
shape="rect" href="getting-started.html">Getting Started</a></li><li><a
shape="rect" href="faq.html">FAQ</a></li></ul><h3 id="Navigation-Documentationhttps://cwiki.apache.org/confluence/pages/viewpage.action?pageId=49534"><a
shape="rect" href="documentation.html">Documentation</a></h3><ul class="alternate"><li><a
shape="rect" href="user-guide.html">User Guide</a></li><li><a shape="rect"
href="manual.html">Manual</a></li><li><a shape="rect" href="books.html">Books</a></li><li><a
shape="rect" href="tutorials.html">Tutorials</a></li><li><a shape="rect"
href="examples.html">Examples</a></li><li><a shape="rect" href="cookbook.html">Cookbook</a></li>
 <li><a shape="rect" href="architecture.html">Architecture</a></li><li><a
shape="rect" href="enterprise-integration-patterns.html">Enterprise Integration Patterns</a></li><li><a
shape="rect" href="dsl.html">DSL</a></li><li><a shape="rect" href="components.html">Components</a></li><li><a
shape="rect" href="data-format.html">Data Format</a></li><li><a shape="rect"
href="languages.html">Languages</a></li><li><a shape="rect" href="security.html">Security</a></li><li><a
shape="rect" href="security-advisories.html">Security Advisories</a></li></ul><h3
id="Navigation-Search">Search</h3><form enctype="application/x-www-form-urlencoded"
method="get" id="cse-search-box" action="http://www.google.com/cse">
+<div class="navigation_bottom" id="navigation_bottom"><h3 id="Navigation-Overview"><a
shape="rect" href="overview.html">Overview</a></h3><ul class="alternate"><li><a
shape="rect" href="index.html">Home</a></li><li><a shape="rect" href="download.html">Download</a></li><li><a
shape="rect" href="getting-started.html">Getting Started</a></li><li><a
shape="rect" href="faq.html">FAQ</a></li></ul><h3 id="Navigation-Documentation"><a
shape="rect" href="documentation.html">Documentation</a></h3><ul class="alternate"><li><a
shape="rect" href="user-guide.html">User Guide</a></li><li><a shape="rect"
href="manual.html">Manual</a></li><li><a shape="rect" href="books.html">Books</a></li><li><a
shape="rect" href="tutorials.html">Tutorials</a></li><li><a shape="rect"
href="examples.html">Examples</a></li><li><a shape="rect" href="cookbook.html">Cookbook</a></li><li><a
shape="rect" href="architecture.html">Architecture</a></li><li><a
shape="rect" href="enterprise-integration-patterns.html">Enterprise
  Integration Patterns</a></li><li><a shape="rect" href="dsl.html">DSL</a></li><li><a
shape="rect" href="components.html">Components</a></li><li><a shape="rect"
href="data-format.html">Data Format</a></li><li><a shape="rect" href="languages.html">Languages</a></li><li><a
shape="rect" href="security.html">Security</a></li><li><a shape="rect"
href="security-advisories.html">Security Advisories</a></li></ul><h3
id="Navigation-Search">Search</h3><form enctype="application/x-www-form-urlencoded"
method="get" id="cse-search-box" action="http://www.google.com/cse">
   <div>
     <input type="hidden" name="cx" value="007878419884033443453:m5nhvy4hmyq">
     <input type="hidden" name="ie" value="UTF-8">
@@ -183,7 +182,7 @@ int size = seda.getExchanges().size();
     <input type="submit" name="sa" value="Search">
   </div>
 </form>
-<script type="text/javascript" src="http://www.google.com/coop/cse/brand?form=cse-search-box&amp;lang=en"></script><h3
id="Navigation-Communityhttps://cwiki.apache.org/confluence/pages/viewpage.action?pageId=49115"><a
shape="rect" href="community.html">Community</a></h3><ul class="alternate"><li><a
shape="rect" href="support.html">Support</a></li><li><a shape="rect"
href="contributing.html">Contributing</a></li><li><a shape="rect"
href="discussion-forums.html">Discussion Forums</a></li><li><a shape="rect"
href="mailing-lists.html">Mailing Lists</a></li><li><a shape="rect"
href="user-stories.html">User Stories</a></li><li><a shape="rect"
href="news.html">News</a></li><li><a shape="rect" href="articles.html">Articles</a></li><li><a
shape="rect" href="site.html">Site</a></li><li><a shape="rect" href="team.html">Team</a></li><li><a
shape="rect" class="external-link" href="http://camel-extra.googlecode.com/" rel="nofollow">Camel
Extra</a></li></ul><h3 id="Navigation-Developershttps://cwi
 ki.apache.org/confluence/pages/viewpage.action?pageId=49124"><a shape="rect" href="developers.html">Developers</a></h3><ul
class="alternate"><li><a shape="rect" href="developers.html">Developer Guide</a></li><li><a
shape="rect" href="source.html">Source</a></li><li><a shape="rect"
href="building.html">Building</a></li><li><a shape="rect" href="javadoc.html">JavaDoc</a></li><li><a
shape="rect" href="irc-room.html">IRC Room</a></li></ul><h3 id="Navigation-ApacheSoftwareFoundation">Apache
Software Foundation</h3><ul class="alternate"><li><a shape="rect" class="external-link"
href="http://www.apache.org/licenses/">License</a></li><li><a shape="rect"
class="external-link" href="http://www.apache.org/foundation/sponsorship.html">Sponsorship</a></li><li><a
shape="rect" class="external-link" href="http://www.apache.org/foundation/thanks.html">Thanks</a></li><li><a
shape="rect" class="external-link" href="http://www.apache.org/security/">Security</a></li></ul></div>
+<script type="text/javascript" src="http://www.google.com/coop/cse/brand?form=cse-search-box&amp;lang=en"></script><h3
id="Navigation-Community"><a shape="rect" href="community.html">Community</a></h3><ul
class="alternate"><li><a shape="rect" href="support.html">Support</a></li><li><a
shape="rect" href="contributing.html">Contributing</a></li><li><a
shape="rect" href="discussion-forums.html">Discussion Forums</a></li><li><a
shape="rect" href="mailing-lists.html">Mailing Lists</a></li><li><a
shape="rect" href="user-stories.html">User Stories</a></li><li><a
shape="rect" href="news.html">News</a></li><li><a shape="rect" href="articles.html">Articles</a></li><li><a
shape="rect" href="site.html">Site</a></li><li><a shape="rect" href="team.html">Team</a></li><li><a
shape="rect" class="external-link" href="http://camel-extra.googlecode.com/" rel="nofollow">Camel
Extra</a></li></ul><h3 id="Navigation-Developers"><a shape="rect"
href="developers.html">Developers</a></h3><ul class="alternate"
 ><li><a shape="rect" href="developers.html">Developer Guide</a></li><li><a
shape="rect" href="source.html">Source</a></li><li><a shape="rect"
href="building.html">Building</a></li><li><a shape="rect" href="javadoc.html">JavaDoc</a></li><li><a
shape="rect" href="irc-room.html">IRC Room</a></li></ul><h3 id="Navigation-ApacheSoftwareFoundation">Apache
Software Foundation</h3><ul class="alternate"><li><a shape="rect" class="external-link"
href="http://www.apache.org/licenses/">License</a></li><li><a shape="rect"
class="external-link" href="http://www.apache.org/foundation/sponsorship.html">Sponsorship</a></li><li><a
shape="rect" class="external-link" href="http://www.apache.org/foundation/thanks.html">Thanks</a></li><li><a
shape="rect" class="external-link" href="http://www.apache.org/security/">Security</a></li></ul></div>
                 <!-- NavigationBar -->
             </div>
           </div>



Mime
View raw message