SOA In the City

A maven repo has been added to the camel-extra google code project, so its no longer necessary to build the camel-hibernate project from scratch. Yay!

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<repository>  
  <id>camel-extra-release</id>  
  <name>Camel Extra Maven repository of releases</name>  
  <url>http://camel-extra.googlecode.com/svn/maven2/releases</url>
</repository>

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<dependency>  
   <groupId>org.apache.camel.extra</groupId>  
   <artifactId>camel-hibernate</artifactId>  
   <version>1.0</version>
</dependency>

(Thanks Joe for the heads up)

How fast you can send messages through ServiceMix is highly dependent on how the embedded ActiveMQ broker within ServiceMix is configured. This is because the ServiceMix NMR uses ActiveMQ as its messaging engine, so choosing the correct connection factories and persistenceAdapter can give you easy gains in performance.

In ActiveMQ 5.0, a new high performance journaling persistence adapter was introduced called the AMQ Message Store.

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 <amq:persistenceAdapter>
         <!-- Goodbye journaledJDBC --> 
         <!--amq:journaledJDBC journalLogFiles="5" dataDirectory="./data/amq"/ -->

         <!-- Hello AMQ Message Store -->
         <amq:amqPersistenceAdapter directory="file://./data/amq"/>

 </amq:persistenceAdapter>

   With JournaledJDBC:

   [java] Overall time: 137701 ms
   [java] Messages per sec: 7.262111386264443
   [java] 
   [java] Time: 139.603
   [java]
   [java] OK (1 test)

   With AMQ Message Store:

   [java] Overall time: 20511 ms
   [java] Messages per sec: 48.75432694651651
   [java]
   [java] Time: 23.556
   [java]
   [java] OK (1 test)

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/trunk/pom.xml
-        <activemq-version>4.1.1</activemq-version>
+        <activemq-version>5.1.0</activemq-version>

/distributions/apache-servicemix/src/main/release/conf/jndi.xml
-       xmlns:amqra="http://activemq.org/ra/1.0"
+       xmlns:amqra="http://activemq.apache.org/schema/ra"

[INFO] The service unit my-jms-consumer-su does not have a dependency which is packaged as a jbi-component or a project property 'componentName'

If you see the above error when trying to build your servicemix service assembly, the trick is to look at the pom.xml for the component with the problem. In this case the ServiceMix SU is'my-jms-consumer-su'.

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        <properties>
                <servicemix-version>3.3.1.0-fuse</servicemix-version>
        </properties>

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        <properties>
                <servicemix-version>3.3.1.0-fuse</servicemix-version>
                <componentName>servicemix-jms</componentName>
        </properties>

This problem only tends to occur when you have multiple su's within the assembly that depend on the same servicemix component (e.g. servicemix-jms). Make sure you add the componentName to all of the Service Unit poms.xml's that use that component.

I've been running performance tests with Fuse ESB 3.3.1 and the spring based JMS endpoints over the last day or two.

One gotcha I've seen mentioned before with ActiveMQ is on the producer side you need to use a PooledConnectionFactory when using springs jmsTemplate. The same applies when using the Servicemix jms:provider endpoint (as its using jmsTemplate under the covers).

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 <jms:provider
      service="test:MySpringProviderService"
      endpoint="mySpringProvider"
      destinationName="queue/OUT"
      connectionFactory="#connectionFactory"
      pubSubDomain="false"
      stateless="false" />

 <bean id="connectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
    <property name="brokerURL" value="tcp://localhost:61616" />
 </bean>

change the connectionFactory to something like this:

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 <bean id="connectionFactory" class="org.apache.activemq.pool.PooledConnectionFactory">
    <property name="connectionFactory">
      <bean class="org.apache.activemq.ActiveMQConnectionFactory">
        <property name="brokerURL" value="tcp://localhost:61616" />
      </bean>
    </property>
    <property name="maxConnections" value="1" />
    <property name="maximumActive" value="1" />
  </bean>

Then by the numbers for my test flow (Jms Consumer->EIP->Bean->JMS Provider & processing/10K worth of messages) ...

     [java] Overall time: 40360 ms
     [java] Messages per sec: 247.77006937561944
     [java] 
     [java] Time: 41.064
     [java] 
     [java] OK (1 test)
     [java]    

     [java] Overall time: 908363 ms
     [java] Messages per sec: 11.008814757976712
     [java] 
     [java] Time: 909.34
     [java] OK (1 test)
     [java] 
 

Those couple of lines of XML make a big difference. Without the pool, the JMS connection is torn down each time and that accounts for the disparity.

A second area to look out for is the jms:consumer endpoint configuration. Make sure you set the cacheLevel to CACHE_CONNECTION (1) or CACHE_CONSUMER (3). The default is CACHE_NONE. Below we set the cacheLevel for the underlying DefaultMessageListenerContainer to CACHE_CONSUMER

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  <jms:consumer service="test:MySpringConsumerService"
        endpoint="mySpringConsumer"
        targetService="test:MySpringProviderService"
        destinationName="queue/SPRING_IN"
        connectionFactory="#connectionFactory"
        concurrentConsumers="1"
        cacheLevel="3"/>

Over on SOS Adrian has posted a set of slides that describe how to build multi-protocol, opensource, web services using JAX-WS.

The presentation gives a great overview of the architecture that allows Celtix Enterprise to deploy services that simulateneosly support multiple payloads (SOAP, XML, JSON) and transports (HTTP, JMS, AMQP). It also give some very helpful pointers on JAX-WS development in general - well worth checking it out.

Today I setup CXF, a new services framework project currently under incubation at Apache. CXF is the merging of the Objectweb Celtix project and the Codehaus XFire project. Its still early days for the project but if you check out the project goals you can get a good idea of the featureset that CXF will eventually offer. Today I just wanted to get as far as running a couple of the demos.

CXF has external dependencies on JDK 1.5 and Maven 2.x. As there is no official release yet you need the build the project directly from the subversion repository. If you want to build the samples you will also need ant installed.

1. Install JDK 1.5 (approx 130MB)

The Sun download page has three different distributions, JDK with NetBeans IDE, JDK with JEE and just the straight 1.5 JDK. I just opted for your basic 1.5 JDK.

2. Install Maven 2.0.4(approx 1.15MB)

The Maven install is just a zip/gz file. You just need to download the zip and unzip it on your system. Then you need to add the /bin directory to your path.

>cd /x1/maven2.0.4
>wget http://www.apache.org/dist/maven/binaries/maven-2.0.4-bin.tar.gz 
>tar -zxvf maven-2.0.4-bin.tar.gz
>export PATH=/x1/maven2.0.4/bin:$PATH

>set Path=\bin;%Path%

3. Install subversion windows or unix (approx 11MB).

Install is similar to maven, download and unzip to your system. Then setup the paths as shown:

>set ANT_HOME=c:\dev\ant
>set PATH=%PATH%;%ANT_HOME%\bin

>export ANT_HOME=/x1/ant
>export PATH=${PATH}:${ANT_HOME}/bin

>cd /x1/cxf
>svn co http://svn.apache.org/repos/asf/incubator/cxf/trunk

Building the source code:

Once the source code is checked out, setup your environment so that java 1.5 is in your path. If you get this wrong you will see an error similar to this when you try and build with a JDK < JDK 1.5.

INFO] ------------------------------------------------------------------------
[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Compilation failure

Failure executing javac, but could not parse the error:
javac: invalid target release: 1.5

I also set things up such that my /bin directory was in the path. To build the project run:

>cd /x1/cxf/trunk
>mvn install

The first time you build CXF, maven will download what seems like an endless amount of dependency jars to a local maven repository on your machine. On windows this is below <> and on linux this was below <>. I have seen periodic download failures where maven fails to download a dependency but re-running mvn install tended to work the second time around.

Another thing to watch out for on windows is that there's a fair bit of shuffling going on in the CXF codebase right now. If the case of a file is renamed, svn on windows cannot detect this and this will leave you scratching your head as to why the project won't build. If you end up with a compile error that doesn't make sense try a 'mvn clean' and then a 'mvn install' and see if that fixes it.

Once the build completes you need to cd into the /distribution directory and run 'maven install' a second time to build a distributable version of cxf. This will produce a distribution with a samples directory which includes the 'hello_world' demo that we want to run.

>cd /x1/cxf/trunk/distribution
>mvn install

>cp /x1/cxf/trunk/distribution/target/cxf-2.0-incubator-M1-SNAPSHOT.tar.gz /x1/cxf-distro/
>cd /x1/cxf-distro/
>tar -zxvf cxf-2.0-incubator-M1-SNAPSHOT.tar.gz

>cd /x1/cxf-distro/cxf-2.0-incubator-M1-SNAPSHOT/samples/hello_world
>ant
>ant -projecthelp
Buildfile: build.xml

Main targets:

 build           build demo client and server
 client          run demo client
 client-servlet  run demo client hitting servlet
 server          run demo server
Default target: build

>ant server&

server:
     [java] Starting Server
     [java] Server ready...

>ant client

client:
     [java] Invoking sayHi...
     [java] Server responded with: Bonjour

     [java] Invoking greetMe...
     [java] Server responded with: Hello dstanley

     [java] Invoking greetMe with invalid length string, expecting exception...

     [java] Invoking greetMeOneWay...
     [java] No response from server as method is OneWay

     [java] Invoking pingMe, expecting exception...
     [java] Expected exception: PingMeFault has occurred: PingMeFault raised by server
     [java] FaultDetail major:2
     [java] FaultDetail minor:1

So after running the demo, it looked like everything worked but there was not much to see. The next step for me was to enable some logging and get a peek at whats happening under the covers.

>cd /x1/cxf-distro/cxf-2.0-incubator-M1-SNAPSHOT/etc
>emacs logging.properties

.level= INFO
java.util.logging.ConsoleHandler.level = INFO 

I had to set the level to FINEST (very verbose!) to see the message going over the wire. Would be nice if this was logged at INFO level.

Thats about it for this time. Hope this article helps. If you spot any problems feel free to point them out.

Steve Rubel posted a podcast this week on the role public companies should play (if any) in providing content for wikipedia. As Steve highlighted previously, wikipedia has a LOT of influence. The wikipedia entry for a company can quite often be one of the most highly ranked pages in Google on a direct search for that company. The podcast primarily discussed the following dilemas: