How to scale Apache Camel route? - apache-camel

Question

I have the following routes:
<camelContext xmlns="http://camel.apache.org/schema/spring">
<threadPoolProfile id="defaultProfile"
defaultProfile="true" poolSize="100" maxPoolSize="200" />
<route>
<from uri="amq:example.MyQueue" />
<setHeader headerName="myRoutingSlipHeader">
<constant>amq:one#amq:two#amq:three#amq:four</constant>
</setHeader>
<log message="Makan" />
<setExchangePattern pattern="InOut" />
<routingSlip uriDelimiter="#">
<header>myRoutingSlipHeader</header>
</routingSlip>
<setExchangePattern pattern="InOnly" />
<log message="End: ${body}" />
</route>
<route>
<from uri="amq:one" />
<to uri="bean:helloBean?method=stepOne" />
</route>
<route>
<from uri="amq:two" />
<to uri="bean:helloBean?method=stepTwo" />
</route>
<route>
<from uri="amq:three" />
<to uri="bean:helloBean?method=stepThree" />
</route>
<route>
<from uri="amq:four" />
<to uri="bean:helloBean?method=stepFour" />
</route>
</camelContext>
<bean id="amq" class="org.apache.activemq.camel.component.ActiveMQComponent"
p:brokerURL="tcp://localhost:61616" p:transacted="true"
p:cacheLevelName="CACHE_CONSUMER" p:concurrentConsumers="20"
p:maxConcurrentConsumers="500" p:idleConsumerLimit="10"
/>
Given that example.MyQueue is preloaded with 1000 messages, and each hello bean's step* methods takes 250ms, when I do camel:run, the performance is still bad. It prints "End: ..." each 1 secs in sequence not parallel. What would be the problem here?
In the following much simple case, I see a strange behavior. When there is no JMS producer putting messages into the queue, the printings happen in sequence. But when there is, the printings happen in parallel. What's the explanation?
<threadPoolProfile id="defaultProfile"
defaultProfile="true" poolSize="100" maxPoolSize="200" />
<route>
<from uri="amq:example.MyQueue" />
<delay>
<constant>1000</constant>
</delay>
<log message="End: ${body}" />
</route>
<bean id="amq" class="org.apache.activemq.camel.component.ActiveMQComponent"
p:brokerURL="tcp://localhost:61616" p:transacted="true"
p:cacheLevelName="CACHE_CONSUMER" p:concurrentConsumers="20"
p:maxConcurrentConsumers="500" p:idleConsumerLimit="10"
/>

Answer 1

Try replacing
<from uri="amq:example.MyQueue" />
with
<from uri="amq:example.MyQueue?concurrentConsumers=200&maxConcurrentConsumers=500" />

Answer 2

The routing slip runs in sequence, and yo do request/reply over JMS (eg the MEP is InOut) so processing one message would take
call amq:one = 250 millis (request/reply)
call amq:two = 250 millis (request/reply)
call amq:three = 250 millis (request/reply)
call amq:four = 250 millis (request/reply)
A total of 1 sec per message.
The AMQ route in < from > could process messages in parallel though. But each message would still take 1 second to process.

Answer 3

I guess routingSlip pattern is synchronized. you need something asynchronized component to handle this. Please check this:http://camel.apache.org/async.html
Just one question, why you need set the ExchangePattern?