Camel's DoFinally block doesn't handle pipeline processing

Solution Verified - Updated -

Environment

  • JBoss Fuse 6.0

Issue

If exception handling is enabled in Camel XML DSL, only the first processor from the pipeline list will be executed. The example of such configuration is demonstrated on the Blueprint snippet below.

<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:camel="http://camel.apache.org/schema/blueprint"
  xsi:schemaLocation="
  http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd
  http://camel.apache.org/schema/blueprint http://camel.apache.org/schema/blueprint/camel-blueprint.xsd">

  <bean id="myException" class="java.lang.RuntimeException">
    <argument value="Booom" />
  </bean>

  <camelContext id="firstContext" trace="false" xmlns="http://camel.apache.org/schema/blueprint">
    <route id="firstRoute">
      <from uri="direct:start"/>
      <doTry>
        <to uri="direct-vm:generateException"/>
        <doFinally>
          <to uri="log:FIRST_FINALLY"/>
          <to uri="log:SECOND_FINALLY"/>
        </doFinally>
      </doTry>
      <to uri="mock:result"/>
    </route>
  </camelContext>

  <camelContext id="secondContext" trace="false" xmlns="http://camel.apache.org/schema/blueprint">
    <onException>
      <exception>java.lang.Exception</exception>
      <handled>
        <constant>true</constant>
      </handled>
    </onException>
    <route id="secondRoute">
      <from uri="direct-vm:generateException"/>
      <throwException ref="myException"/>
    </route>
  </camelContext>

</blueprint>

If you execute the Blueprint snippet above with Camel in version lower than 2.12.0, you will see only entry for FIRST_FINALLY logger and not for SECOND_FINALLY logger. Upgrading version of the Camel to 2.12.0 will result in both messages being printed.

Resolution

This bug has been fixed in Camel 2.12.0. If upgrade for the Camel 2.12.0 or above is not possible, the following workaround for the discussed issue could be considered - using multicast [1] instead of pipeline processing.

It is not always possible to replace pipeline processing with multicast pattern, however for some cases (in particular if messages in block can be sent independently) this approach may work as a workaround.

<doFinally>
  <multicast>
    <to uri="log:FIRST_FINALLY"/>
    <to uri="log:SECOND_FINALLY"/>
  </multicast>
</doFinally>

[1] http://camel.apache.org/multicast

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