SelfDiagnose and OGNL and check your deployment

June 16, 2008

Some time ago I wrote about selfdiagnose-the-world-according-to-my-atg-application.
Since then SelfDiagnose has added some nifty features. The latest release of SelfDiagnose now adds support for OGNL. This gives SelfDiagnose some extra punch. I can now use constructions like:

<checkvaluematches
    value="${@java.lang.Integer@parseInt(configList.length)}"       
    comment="Number of configured Endeca instances"
    pattern=".*" />

or constructions like

 <checkendecaservice host="${configList[0].host}" 
port="${configList[0].port}"
query="N=0"
comment="Endeca instance 1 connection test"/>

The ${configList[0].port} is a typical OGNL construction.

The CheckEndecaService can also return the Endeca com.endeca.navigation.ENEQueryResults response.
With OGNL you can easily dissect this Endeca response.

This can be extremely handy to query for the latest Forge or pipeline version of an Endeca build in the different ATG environments were you cannot directly access those services! For instance in production.


SelfDiagnose, the world according to my (ATG) application

April 17, 2008

We have all been there, when developing a J2EE application, the environment nightmares. When your stuff goes through the different stages of integration, acceptance, production etc. Stuff just breaksTM, because of misconfiguration. Configuration which you have no control over.

Missing a database table here, a JNDI binding forgotten, a URL not reachable, weird classloading nightmares, because another jar is being used in acceptance.

Here is where SelfDiagnose comes to the rescue. Somehow this little gem gets no press whatsoever. Lately some new tasks have been added to the mix. This blog by Ernest explains something about compile-time dependencies. But more interestingly (to me), SelfDiagnose now contains an CheckAtgComponentProperty task and a CheckEndecaService.
The CheckAtgComponentProperty lets you check an ATG property. I know this can be done with ATG’s component browser as well, but hold on.
The CheckEndecaService will check the availability of the Endeca service.

The combination of these tasks and the chaining of these creates a powerful diagnosis. See the following snippet of code, where first an ATG property is queried which then is chained to the Endeca task. Another nifty SelfDiagnose feature.
This code is heavily customer oriented, but you will get the idea.

    1 <checkatgcomponentproperty
    2     component="/wsp/common/services/search/balancer/connections/EndecaConnection"
    3     property="host"
    4     comment="Endeca Host"
    5     var="eneHost"/>
    6 <checkatgcomponentproperty
    7     component="/wsp/common/services/search/balancer/connections/EndecaConnection"
    8     property="port"
    9     comment="Endeca Port"
   10     var="enePort"/>
   11 <checkendecaservice host="${eneHost}" port="${enePort}" query="N=0"/>

The real cool and not so well understood part about SelfDiagnose in my opinion, is that it will check a bunch of tasks from inside the environment you are executing. This means that the above example will output the ATG configuration and check the configured Endeca instance of the actual environment.
Hitting the selfdiagnose.html url will show:

Endeca Diagnose

I just mentioned the ATG and Endeca tasks, but there is a lot more which can be extremely helpful.
This nifty feature can save some energy when something is misconfigured. Checking the selfdiagnose URL can save a lot of time.


Daring Devious Darryl Dude Needs Feedback and a bit of money along the way

January 17, 2008

Are you living in the Netherlands and need a book, a nice Cd, perhaps a Dvd, the latest Wii game or what have you, use the this affiliate thingabee. You will make Darryl happy.

I know I will use it.

Darryl’s commuting habits need a faster car.


Do not use the ATG ApplicationLogging API

November 4, 2007

In my current project we use atg.nucleus.logging.ApplicationLogging. This is with ATG 2007 on JBoss.
At the start it was decided to use the ATG logging API in stead of Log4J (or
any other Java logging framework). ATG and ApplicationLogging was common practice, why not use it I was told.
Later when I saw the code littered with complicated logging statements where the programmer had to include the method from which the Logging statement was executed I was not so sure.

1 Log4J ConversionPattern

Adding the containing method to your logging statement is not necessary. You can use the Log4J ConversionPattern %M in the PatternLayout.
which is used to output the method name where the logging request was issued.
It should be used with care of course since it is a performance drain. But we can alter this at runtime so that’s no biggie (see 2). But…
ATG logging attaches to JBoss logging, however the %M is lost since the ATG logging method is considered as the issuing method. So the
logDebug logInfo, LogError etc, are reported to be the issuing method, in stead of the actual method. Pretty useless.
This would not have happened if ATG ApplicationLogging was not used, but plain Log4J.

2 Different logging level

A used argument is that you can alter the logging level of the individual components in the ATG admin console.
This is trivial. You can also do this in Log4J.xml with the Log4J categories.

3 Dynamic Logging Level

Another argument: You can change the logging level in ATG without restarting the server.
Look at JBoss Log4JService. This automatically picks up changes to Log4J.

Moral

  • Don’t use atg.nucleus.logging.ApplicationLogging you butcher Log4J features.
  • Don’t think, because you have some patterns which used to work, that that is the best pattern in the future.
    What worked with DAS does not necessarily work with JBOSS.
  • Think.

Bundling external library classes inside a jar

September 13, 2007

Some software suppliers are bundling external classes inside their propriety jars. A good, or should I say bad, example is ATG…..

JAXB conflict

With GlassFish Metro’s wsimport.sh script I generated Java interfaces and other supporting classes from a wsdl file. In a small test project it all worked like a charm.

Then I copied my code to an ATG project which needed my code. My testcase suddenly failed with a java.lang.NoSuchMethodError: javax.xml.bind.JAXBContext.newInstance(..
Ouch.

It took me some time to understand the problem. The problem is that the ATG das2007.1.jar contains a lot of external libraries. For instance Xerces or Xalan. However they changed the namespace to for instance atg.apache.xerces.. So conflicts are less likely.

But it also contains javax.xml.bind.JAXBContext. Grr this is JAXB 1 and my JAX-WS Metro stuff needs JAXB 2. Of course I can change the class-path order and I can do this in Eclipse, so my tests will work.
However ATG specification says that ATG-Required modules will be started up, in the order specified, before any modules started with ATG-Class-Path. So DAS will always be loaded before any custom jars according to the specification… I have not validated this yet, but I’m afraid that the specification is the way it works and thus my code will not work inside the Application container.

This will mean that this lovely solution will not work

And Spring, and CGLib, and Mozilla packages, and Sun packages and IBM BSF, Apache Commons etc etc?

IBM BSF? The Bean Scripting Framework got promoted to Jakarta in 2002 and for some time now it has an Apache namespace and not an IBM namespace. That is some old stuff in the das jar. This is taking “If it aint broke don’t fix it” to a new level.
And does anybody else find it funny that an ATG jar, especially the one containing Nucleus, contains Spring classes. Ok it is just the Spring AOP classes, but still. Nucleus and Spring IOC are birds of a feather. These are just some of the examples of some of the embedded classes.

Why bundle libraries?

I sort of understand that you want to control the versions of external libraries you need, but bundling them in stealth mode is bad practice in my opinion. Especially if you are a framework like ATG. Frameworks don’t live in a vacuum, they need extra custom code and thus clashes are likely. I rather see the jars and documentation for which library versions your product is tested.

I’m not really fluent in Ruby but Ruby’s require_gem with the version argument sounds like a nice feature.


ATG 2007.1 on Mac OS X with MySQL

August 13, 2007

For some weeks now ATG 2007.1 is available. My entry about installing ATG on Mac OS X explained how to install ATG 2006.3 on Mac OS X Tiger which is not supported by ATG . It got a few hits, so perhaps an update is needed.

Pre installation

  • Have jboss-4.0.5GA ready. This is the only version supported by ATG 2007.1.
  • Have MySQL ready. Only 5.0.20 is supported. However I have used 5.0.45 and so far it seems to be working fine. Make sure you use the InnoDB engine instead of the MyISAM.
  • Create an ATG user on MySQL in a way you seem fit
  • Add export JBOSS_HOME=<your JBOSS 4.0.5GA path here> to .bash_login. If you use another shell, you know what to do.
  • Take care of your permissions.
  • Download ATG2007.1 for Unix

Installation and configuration

  • Run ATG2007.1.bin
  • When asked to enter the path where to install ATG, remove the space. It will make things easier.
  • When asked for JAVA_HOME use /System/Library/Frameworks/JavaVM.framework/Versions/ 1.5.0/Home or your preferred version.
  • Drop your license files in <ATG folder>/home/localconfig
  • Add the following line export ATGJRE=/System/Library/Frameworks/JavaVM.framework/ Versions/CurrentJDK/Commands/java to dasEnv.sh
  • Copy MySQL JDBC driver (mysql-connector-java-5.0.7-bin.jar) to <JBOSS_HOME>/server/atg/lib
  • Add a mysql-ds.xl to <JBOSS_HOME>/server/atg/deploy and fill in the correct database name etc.
  • Create a file, like this: /home/localconfig/atg/dynamo/service/jdbc/JTDataSource.properties
    The ATG documentation states to create a jbossconfig folder with a change to a manifest to point to that path. I skipped that.
  • Edit this JTDataSource.properties. It should contain:
    JNDIName=java:/MySqlDS
    and
    $class=atg.nucleus.JNDIReference
  • Run datascripts:
    • /Applications/ATG2007.1/DAS/sql/install/mysql/das_ddl.sql
    • /Applications/ATG2007.1/DPS/sql/install/mysql/dps_ddl.sql
    • /Applications/ATG2007.1/DSS/sql/install/mysql/dss_ddl.sql
    • /Applications/ATG2007.1/DCS/sql/install/mysql/dcs_ddl.sql

    I used mysql -D <dbname> < /Applications/ATG2007.1/DAS/sql/install/mysql/ das_ddl.sql --user=<username> --password=<password>

Some notes

Adding Darwin to <ATG folder>/home/bin/DynamoEnv.sh is not something I use anymore as I did in 2006.3. I will assume Solaris. This will make patching easier, as Robert Hellwig found out.

Unlike ATG 2006.3 ATG2007.1 JTDatasource.properties can contain $class=atg.nucleus.JNDIReference

The executing of the SQL scripts was not correct in the previous Blog. The user and password command was wrong. Why didn’t anybody tell me?

On the previous blog entry, I got some questions on how you can tell MySQL to use InnoDB. Check your my.cnf or my.ini file. It’s in the ATG documentation:
ATG Doc


Debugging Nucleus components in JBoss with Eclipse

May 27, 2007

It seems that ATG developers are creatures of old habits. Most of them use VI or Emacs because they are used to it. Perhaps because they think it is better…. Only my observation of course. For all I know a lot of them are using Textmate with their custom ATG bundles.

And debugging? : through debug logging statements…

Since Java 1.2 we have the Java Platform Debugger Architecture. It amazes me how few are using it..

If you don’t know how to debug with JPDA when developing for ATG on JBoss with Eclipse it’s easy:

  • First start JBoss with debugging enabled. Do this by adding the line:

JAVA_OPTS="$JAVA_OPTS -Xdebug -Xrunjdwp:transport=dt_socket, address=5000,server=y,suspend=n"

to the run.conf file in the <JBOSS_HOME>/bin folder and then

  • create a debug configuration in Eclipse. Use the Remote Java Application, Socket Attach. Use the port as defined in the JAVA_OPTS. Port 5000 in this example.

It should look something like this:
Eclipse debugging

Happy debugging