Eric D. Schabell

Fedora 12 NetworkManager update breaking GSM connection

eric@schabell.org (eric@schabell.org) — Mon, 08 Mar 2010 06:46:15 PST

My latest Fedora 12 update broke my Mobile Broadband GSM connection. I kept seeing this in my message log:

6516 Mar  8 12:22:49 localhost NetworkManager:   (hso0): device state change: 3 -> 4 (reason 0)
6517 Mar  8 12:22:49 localhost NetworkManager:   Activation (hso0) Stage 1 of 5 (Device Prepare) scheduled...
6518 Mar  8 12:22:49 localhost NetworkManager:   Activation (hso0) Stage 1 of 5 (Device Prepare) started...
6519 Mar  8 12:22:49 localhost NetworkManager:   (hso0): device state change: 4 -> 6 (reason 0)
6520 Mar  8 12:22:49 localhost NetworkManager:   Activation (hso0) Stage 1 of 5 (Device Prepare) complete.
6521 Mar  8 12:22:49 localhost NetworkManager:   Activation (hso0) Stage 1 of 5 (Device Prepare) scheduled...
6522 Mar  8 12:22:49 localhost NetworkManager:   Activation (hso0) Stage 1 of 5 (Device Prepare) started...
6523 Mar  8 12:22:49 localhost NetworkManager:   (hso0): device state change: 6 -> 4 (reason 0)
6524 Mar  8 12:22:49 localhost NetworkManager:   Activation (hso0) Stage 1 of 5 (Device Prepare) complete.
6525 Mar  8 12:22:49 localhost modem-manager: (ttyHS2) opening serial device...
6526 Mar  8 12:22:49 localhost modem-manager: Modem /org/freedesktop/ModemManager/Modems/0: state changed (disabled -> enabling)
6527 Mar  8 12:22:50 localhost modem-manager: Modem /org/freedesktop/ModemManager/Modems/0: state changed (enabling -> enabled)
6528 Mar  8 12:22:50 localhost modem-manager: Modem /org/freedesktop/ModemManager/Modems/0: state changed (enabled -> disabled)
6529 Mar  8 12:22:50 localhost NetworkManager:   (hso0): device state change: 4 -> 3 (reason 0)
6530 Mar  8 12:22:50 localhost NetworkManager:   (hso0): deactivating device (reason: 0).
6531 Mar  8 12:22:50 localhost NetworkManager:   stage1_enable_done(): GSM modem enable failed: (32) SIM PIN required
6532 Mar  8 12:22:50 localhost NetworkManager:   (hso0): device state change: 3 -> 9 (reason 0)
6533 Mar  8 12:22:50 localhost NetworkManager:   Activation (hso0) failed.
6534 Mar  8 12:22:50 localhost NetworkManager:   (hso0): device state change: 9 -> 3 (reason 0)
6535 Mar  8 12:22:50 localhost NetworkManager:   (hso0): deactivating device (reason: 0).

The key here was the line:

  stage1_enable_done(): GSM modem enable failed: (32) SIM PIN required

Some looking around and it appears that the last update to NetworkManager broke it:

Name : NetworkManager
Arch : x86_64
Epoch : 1
Version : 0.7.998
Release : 2.git20100106.fc12

A simple downgrade will fix this to back you up to the previous version, here is mine:

Name : NetworkManager
Arch : x86_64
Epoch : 1
Version : 0.7.996
Release : 6.git20091021.fc12

To do this you use the following command:

$ sudo yum downgrade NetworkManager

Restarted and the GSM card worked as advertised!

Drools JBoss Rules 5.0 Developer's Guide review

eric@schabell.org (eric@schabell.org) — Sun, 28 Feb 2010 07:08:14 PST

This book from Packt Publishing is the best one I have run across in 2009. Often they are a bit off the mark on order, cohesion and readability, but this one is spot on for business rules developers.

I think that this will become the bible for JBoss BRMS developers as it covers all the details you need to get your projects rolling.

After a very short introduction (as it should be, we are developers and want to get started), this book dives into the basic rules syntax and validation. You are then walked through the process of how to load facts into a knowledge session which is all about data transformation.

When dealing with rules we often have to make sure that the business users are not left out in the cold. The author take a good look at Domain Specific Language (DSL) implementation in Drools, decision tables and dealing with Drools Flow. These are all supported with examples and code to feed the developer learning how to make use of these elements of a rules implementation.

A walk through stateful sessions is followed by Complex Event Processing (CEP) with Drools Fusion and supported with a fraud detection example. This is really interesting and feeds me at the technical depth I expect from a developers guide.

There is an entire chapter spent on the details within Drools Flow and this is followed up with a sample application to walk you through all the details of setting up and executing a rules project. Testing is touched on briefly, along with some integration topics (Spring and the JSR94 standard). Finally, the book finishes up with a look at performance, providing you with insights to help you optimize your rules projects.

This book is well written, contains good technical depth and is very thorough. There is not much left for you to look for on JBoss with regards to your rules projects. You need this book on your development shelf if you are working with JBoss and rules in your organization.

JBoss Drools Business Rules review

eric@schabell.org (eric@schabell.org) — Sun, 28 Feb 2010 06:52:14 PST

I read this book early in 2009 when I was diving deeper into the JBoss Business Rules Management System (BRMS) and found it to be a good overview.

It is light on the technical depth, but this is not a problem and all crucial parts of the system are covered. It appeals to both business types and technical types trying to get a grasp of the Drools project components.

The book begins with a good introduction to rules and business rules in an organization, provides help with setting up your Drools environment and provides a tour of the following components in your business rules infrastructure:

Guvnor, the guided rule editor
JBoss IDE, the developers rule editing environment
Testing your rules
Managing your rules from Excel
Domain Specific Languages (DSL)
RuleFlow, graphical rule design

Furthermore, the book takes you through deploying rules in a real life situation and details how the rule engine works all the way down to the RETE algorithm.

This book is a very good place to start your JBoss Business Rules experience, whether you have done rules development before or not. It will get you up to speed on rules, is easy to read, well structured and before you know it you will be designing your first rules package.

JBoss Developer Studio 3.0.0.RC1 optimizations

eric@schabell.org (eric@schabell.org) — Thu, 18 Feb 2010 14:15:15 PST

For those lucky customers out there that have been evaluating or playing with the customer releases of the up-coming 3.0.0 release, you might have noticed the default setup is a bit slow to start.

I was playing with my eclipse.ini file parameters and got mine to start 5x faster with these settings, maybe they will help you too:

--launcher.library
plugins/org.eclipse.equinox.launcher.gtk.linux.x86_64_1.0.200.v20090519
-vmargs
-Xms256m
-Xmx1024m
-XX:-UseParallelGC
-XX:+AggressiveOpts
-XX:-UseConcMarkSweepGC
-XX:MaxPermSize=512m
-Dosgi.bundles=reference:file:org.eclipse.equinox.simpleconfigurator_1.0.101.R35x_v20090807-1100.jar@1:start,org.eclipse.equinox.transforms.xslt@1:start,org.jboss.tools.equinox.transforms.xslt@1:start

JBoss Developer Studio performance optimizations (amazing speed improvements)

eric@schabell.org (eric@schabell.org) — Thu, 18 Feb 2010 06:08:16 PST

Working in a virtualized environment and very sick of the slow JBDS startups, we went looking for some help in the settings. Here is what we found:

The tricks is to use the optimization done in JDK 1.6 (VMarg2) and the new agresivity of the Just In Time compiler (JIT) for VMarg3. Add theses VM arguments to eclipse.ini (file is located in your Eclipse directory, one to each line)

-XX:-UseParallelGC

-XX:+AggressiveOpts

-XX:-UseConcMarkSweepGC

What are these doing:

VMarg1	-XX:-UseParallelGC	Use parallel garbage collection for scavenges. (Introduced in 1.4.1) this will create more threads running in parallel, so the second processor will be put in use
VMarg2	-XX:-UseConcMarkSweepGC	Use concurrent mark-sweep collection for the old generation. (Introduced in 1.4.1) The Eclipse GUI will feel more responsive as memory will be reclaimed without blocking VM executions.
VMarg3	-XX:+AggressiveOpts	Turn on point performance compiler optimizations that are expected to be default in upcoming releases. (Introduced in 5.0 update 6.)

JBoss Developer Studio / Eclipse debug ignores breakpoints fix

eric@schabell.org (eric@schabell.org) — Thu, 18 Feb 2010 06:08:16 PST

This week I ran into some of my Java projects where the debugging was ignoring breakpoints in my JBoss Develoepr Studio / Eclipse IDE's. I thought this was maybe just something in JBoss Developer Studio (JBDS), but it appears to be an issue with Eclipse too.

This was the fix for me, in JBDS /Eclipse:

Window -> Preferences -> Java -> Installed JRE's:

edit JRE being used

edit 'Default VM Arguments' line
-XX:+UseParallelGC

Fixes it for me!

jBPM v3.2.x Hibernate persistence bug - missing javax.jcr.Node

eric@schabell.org (eric@schabell.org) — Fri, 05 Feb 2010 06:49:31 PST

While trying to show hibernate persistence with jBPM v3.2.x I ran into a problem with a missing dependency. Details of the simple POJO class I was persisting, the hibernate mappings, error message encountered and solution tracing are provided below for those interested:

package com.sample.model;

// Sample person object for persistence checking.
public class Person {

 private Integer ssn;
 private String lastname;
 private String firstname;

 public void setFirstname(String firstname) {
  this.firstname = firstname;
 }
 public String getFirstname() {
  return firstname;
 }
 public void setLastname(String lastname) {
  this.lastname = lastname;
 }
 public String getLastname() {
  return lastname;
 }
 public void setSSN(Integer ssn) {
  this.ssn = ssn;
 }
 public Integer getSSN() {
  return ssn;
 }
}

The hibernate mappings were put into the person.hbm.xml file:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
 "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.sample.model" auto-import="false" default-access="field">
  <class name="Person">
   <id name="ssn" column="SSN"><generator class="native" /></id>
   <property name="lastname" column="LASTNAME" />
   <property name="firstname" column="FIRSTNAME" />
  </class>
</hibernate-mapping>

// First the errors I was getting in my logging (just the last bits):
...
DEBUG GraphElement - event 'process-start' on ProcessDefinition(main_flow)
 for Token(/)
DEBUG VariableContainer - create variable 'person' in 'TokenVariableMap[/]' 
with value 'com.sample.model.Person@1dfc547'
DEBUG Converters - adding converter 'D', 'org.jbpm.context.exe.converter.DoubleToStringConverter'
DEBUG Converters - adding converter 'C', 'org.jbpm.context.exe.converter.CharacterToStringConverter'
DEBUG Converters - adding converter 'B', 'org.jbpm.context.exe.converter.BooleanToStringConverter'
DEBUG Converters - adding converter 'Y', 'org.jbpm.context.exe.converter.BytesToByteArrayConverter'
DEBUG Converters - adding converter 'A', 'org.jbpm.context.exe.converter.DateToLongConverter'
DEBUG Converters - adding converter 'R', 'org.jbpm.context.exe.converter.SerializableToByteArrayConverter'
DEBUG Converters - adding converter 'I', 'org.jbpm.context.exe.converter.IntegerToLongConverter'
DEBUG Converters - adding converter 'H', 'org.jbpm.context.exe.converter.ShortToLongConverter'
DEBUG Converters - adding converter 'G', 'org.jbpm.context.exe.converter.FloatToDoubleConverter'
DEBUG Converters - adding converter 'F', 'org.jbpm.context.exe.converter.FloatToStringConverter'
DEBUG Converters - adding converter 'E', 'org.jbpm.context.exe.converter.ByteToLongConverter'
DEBUG HibernateLongIdMatcher - no current context so valueClass 
cannot be stored as a long-id-ref to a hibernate object
DEBUG HibernateStringIdMatcher - no current context so valueClass 
cannot be stored as a string-id-ref to a hibernate object

The path to the missing interface we traced from jbpm-jpdl.jar -> org.jbpm.context.exe -> jbpm.varmapping.xml file contains the following mapping:

 <!-- JSR 170 JCR Node -->
    <jbpm-type>
      <matcher>
        <bean class="org.jbpm.context.exe.matcher.JcrNodeMatcher" />
      </matcher>
      <variable-instance class="org.jbpm.context.exe.variableinstance.JcrNodeInstance" />
    </jbpm-type>

This leads to org.jbpm.context.exe.matcher.JcrNodeMatcher.class which imports the class not included in jBPM:

/*
 * Snipped the license code.
 */
package org.jbpm.context.exe.matcher;

import javax.jcr.Node;        <<<<<<<<<<<<<< MISSING!!!!

import org.jbpm.context.exe.JbpmTypeMatcher;

public class JcrNodeMatcher implements JbpmTypeMatcher {

  private static final long serialVersionUID = 1L;

  public boolean matches(Object value) {
    return (Node.class.isAssignableFrom(value.getClass()));
  }

}

My solution: added external jar to projects classpath, jcr-1.0.jar which provides the needed interface interface. Hope this saves you some time!

Upgrade Fedora 11 to Fedora 12 howto

eric@schabell.org (eric@schabell.org) — Thu, 04 Feb 2010 00:16:52 PST

A few simple steps to upgrade:

# As root you would like to have a clean start to the
# upgrade, so get an update out of the way.
#
$ yum update rpm

$ yum -y update

$ yum clean all

# Should a new kernel install/update require it,
# reboot before continuing with the rest.
#
# Then install the preupgrade package.
#
$ yum install preupgrade

# For console upgrade, use:
#
$ preupgrade-cli "Fedora 12 (Constantine)"

# If you like gui's to upgrade, use this.
#
$ preupgrade

This is exactly the same process as I previously described with Fedora 10 to Fedora 11 upgrade.

Update Fedora 12 to Firefox 3.6 howto

eric@schabell.org (eric@schabell.org) — Tue, 02 Feb 2010 01:01:46 PST

I got tired of waiting for the main Fedora 12 repositories to provide Firefox 3.6. I dug around a bit and the following will get you a Firefox 3.6 version installed on your Fedora 12, so what are you waiting for?

$ sudo yum --enablerepo=rawhide update firefox

SNS Bank award lunch: 2009 Silver award for BPM & Workflow excellence

eric@schabell.org (eric@schabell.org) — Sat, 06 Feb 2010 07:06:45 PST

After much planning we were finally able to celebrate the SNS Bank 2009 Silver award for Global Excellence in BPM & Workflow. We got together with the entire team; the two authors, the project manager, the head of Java development and one of the original developers.

It was a nice three course lunch filled with stories about all the work that went into getting this chapter published and what led up to the award.

I presented the winners trophy to the SNS Bank and we look forward to following their BPM innovations into the future.

As you can see, the winners cup was used for the traditional winners champagne drinking ceremony.

Finally, we took a group photo to commemorate the event. I think this story is finally finished, but who knows? ;-)

Jazoon 2010 session submission

eric@schabell.org (eric@schabell.org) — Fri, 29 Jan 2010 01:25:05 PST

Just submitted a session to Jazoon 2010 that takes place on 1-3 June, 2010 in Zurich, Switzerland. I am curious as to what traction is in the market for this information.

Future proofing SOA projects with JBoss jBPM migration strategies
If you have applied all the best intentions in your jBPM projects you might now be searching for best practices. Based on experiences from the trenches, we offer insights into jBPM best practices that are meant to ensure future migration flexibility.

This session takes you on a tour of the following four tactical migration areas in a jBPM project:

    * process initialization layer
    * process definition & design layer
    * process implementations layer
    * SOA interaction layer

As we peel back these layers we will detail best practices and design tactics that will greatly simplify your jBPM future. A running case will be use based on a JBoss EAP / jBPM award winning implementation at SNS Bank from the Netherlands.

Computable.nl Open Source - comments published on "Open Source: teveel vrijheid is ook niet goed"

eric@schabell.org (eric@schabell.org) — Thu, 28 Jan 2010 04:46:13 PST

Computable has published an opinion article written by a friend of mine entitled: Open source: teveel vrijheid is ook niet goed.

My comment was published along with the article, see the third cited expert under the article.

JBoss World 2010 jBPM session submission

eric@schabell.org (eric@schabell.org) — Wed, 20 Jan 2010 12:29:27 PST

I have submitted a session to JBoss World 2010 that will be in Boston, MA from June 22 - 25. The speakers list will be announced on 1 March 2010, so fingers crossed for the following abstract:

Sun Tzu and the art of jBPM migrations
Sun Tzu once wrote, "Strategy without tactics is the slowest route to victory.” If you have applied all the best intentions in your jBPM projects you might now be searching for best practices. Based on experiences from the trenches, we offer insights into jBPM best practices that are meant to ensure future migration flexibility.

This session takes you on a tour of the following four tactical migration areas in a jBPM project:

process initialization layer

process definition & design layer

process implementations layer

SOA interaction layer

As we peel back these layers we will detail best practices and design tactics that will greatly simplify your jBPM future. A running case will be use based on a JBoss EAP / jBPM award winning implementation at SNS Bank from the Netherlands.

jBPM Developer Guide review - chapters 7 - 12 (part III of III)

eric@schabell.org (eric@schabell.org) — Sat, 20 Feb 2010 06:44:59 PST

Click on book to buy!

Back to jBPM Developer Guide review part II
Back to jBPM Developer Guide review part I

My final part of this book review will cover the last six chapters and provide a final conclusion.

Chapter 6
This chapter is an in depth look at how jBPM deals with persistence.

A must read chapter.

Chapter 7
Tasks are dealt with in the chapter with a very good example to show you how it all works. At this point that the book gives us a practical example instead of homework, bit of inconsistency here.

Still, a must read chapter.

Chapter 8
More persistence, dealing with how it happens when you hit wait states. Would have like to see more about how this is a best practice as too many jBPM implementations take the initial lead from the provided examples found on-line and implement everything in Nodes. Nothing mentioned about lazy initialization or loading in Hibernate, something you will run into in advanced cases when you implement your complicated processes.
A nice end to this chapter is provided by updating the running example process to use the techniques discussed in this chapter. This is nice.

A good chapter you need to read.

Chapter 9
More than you really need to know about process variables, but that is exactly what I want from a developers guide type of book. This chapter is a perfect example of what I want from every chapter in this type of book, well done! Strange finish though, the homework section is back in this chapter.

Don't miss this chapter, good developer guide material that will help make you the jBPM guru in your development shop.

Chapter 10
Here the author deals with advanced topics from jPDL, which means forks, joins, super states, process states, email nodes and property passing in your handlers. It is thorough, but I would really have expected some more suggestions as to best practices, especially on forks and joins, which WILL bite you in the butt on your real life implementations. It is a good chapter, finishing off jPDL for you.

Don't want to skip this chapter or you will have a half empty toolbox at work.

Chapter 11
When I read the title I was expecting advanced topics from real life practices to tell me about the best practices using the previous material. It turns out to be about applying the chapter 10 material to the running example, thus the author takes us through adding in super states and process states to his example process.

A very good handling of the asynchronous usage of jBPM and how the jobExecutor works finishes out this chapter. Very important stuff and I thought it was forgotten. It would have been more symmetric to first introduce this in the previous chapter and then apply it as was done with the other advanced topics, but this is a matter of style.

A good chapter to read and pay attention to the jobExecutor section.

Chapter 12
With a title of 'Going enterprise,' I was curious how we were going to finish out the book as this was the last chapter. Well, it is a good overview of the deeper configuration issues encountered when working in JEE environments.
There were lots of solution tips sprinkled in this chapter, nice touch. The jobExecutor is handled but this time interacting with JMS queues. Timers, reminders and the Mail service are covered.

Then we hit a wall. The book it seems is now finished. No conclusion, no tying it all together with the final look at our running example project and no summary of the entire book. This feels like I am missing chapters or left hanging. Bummer.

This chapter is very important none the less, don't think of skipping this one.

Final conclusion

So my final conclusions are that this book is very much an improvement on the previous jBPM PACKT publishing offerings. It does cover jBPM fairly well and for a beginner it is now the place to start your education (should you decide not to take the Red Hat education offerings). Go out and get your copy, it will help you along the road to becoming a guru in your jBPM development projects.

What about my running list of questions and impressions? Here they are for posterity, maybe they will make it into future publications:

extremely disappointed with the readability/editing job done by PACKT publishing as mentioned in part I (again, this has nothing to do with the author)

no resources or references section in the book
lots of Wikipedia references in-line, never a good thing to use as a primary reference
miss exception handling as an advanced feature?
in handling of a Nodes and Transitions nothing is mentioned about dynamic transitions
no best practices given when implementing jBPM projects?
the author gives us "homework" in the first three chapters, but then it just stops until the ninth chapter, rather a shame

jBPM Developer Guide review - chapters 1 to 6 (part II of III)

eric@schabell.org (eric@schabell.org) — Sat, 20 Feb 2010 06:25:58 PST

Click on book to buy!

Back to jBPM Developer Guide review part I

This book makes the promise with the title that it will be giving us developers an in depth look at jBPM. This is the measure I am using when reviewing each chapter, asking myself if it fills a need I have as a developer. This is not a beginners book is the impression I had when looking at the cover. Also of note, this is not a cheap book, running over 48 Euro + shipping costs, so I would expect value for that kind of money.

I will jump right into the review, providing my impressions of each of the first six chapters:

Chapter 1
This is an introduction chapter that tosses out lots of technological terms for the new jBPM developer.

This chapter you can skip.

Chapter 2
This chapter attempts to take you through some basic BPM functionality for implementing a process engine (just a very basic one). It is kind of fun to see happen, but not needed for jBPM usage.

This is also a chapter you can skip without missing anything important for your jBPM development experience.

Chapter 3
This chapter is going to get into the nitty gritty with a jBPM deep dive. This is the feeling I am getting. A small comment, the jBPM background/history is a bit on the thin side and not founded in facts. Also first we are forced to take a walk through the jboss.org community stack, nothing to do with jBPM yet.

On page 75, the real business starts, we dive into jBPM and build it via Maven and SVN. I really like this, as most books on community projects fail to give even a simple Maven explanation. You will have no excuses to not have a running jBPM check out from the community projects repository after this chapter. We are off and running!

From page 75 onwards, this is a must read chapter.

Chapter 4
In depth dive into jPDL, nothing but good things to say about this.

A must read chapter.

Chapter 5
A real example project is setup, starting from the business side which is nice for the beginners but a bit of a waste for the developers. We never are involved with this part of the project and have to make do with the results.

The only let down on this chapter is the finishing section, which requires you to download the provided projects code to see how you can create an initial unit test to march through the process as designed in this chapter. This is such a fundamental step in every project you will do in jBPM that I am a bit disappointed that the author did not walk us through the code snippets in the chapter itself.

This is a must read chapter.

Chapter 6
Persistence and all things devoted to how jBPM uses this and how you set it up. Very good detail and clarity.

A must read chapter.

I will post a final part soon with chapters 7 - 12 and my final conclusions. I also want to keep a running list of questions and impressions that arise during my reading/reviewing. I will list older items in italics, new items in normal text and remove items as they are resolved.

Impressions and questions:

no resources or references section in the book
lots of Wikipedia references in-line, never a good thing to use as a primary reference
in handling of a Nodes and Transitions I am wondering if dynamic transitions will be handled?
are there any best practices to be given when implementing jBPM projects?
I don't understand why all these technologies have been used in a jBPM Developer Guide (Drools, ESB, Maven, MySQL, Eclipse and SVN)
the author gives us "homework" in the first three chapters, but then it just stops until the ninth chapter, rather a shame
miss exception handling as an advanced feature?

Stay tuned for the final part III of this review series, coming soon!

Onwards to jBPM Developer Guide review part III

jBPM Developer Guide review - introduciton (part I of III)

eric@schabell.org (eric@schabell.org) — Sat, 20 Feb 2010 06:24:47 PST

Click on book to buy!

The book arrived and I will be starting my review. I plan to split the review into three parts to cover this introduction, the first six chapters and finishing up with the last six chapters.

The jBPM Developer Guide is a PACKT publishing offering, which is publishing books on technical subjects for sme time now. They offer good quality books, with nice artwork and feel to them. This one is 350 pages and feels like you should be able to carry it with you as a reference guide to jBPM. PACKT is based in Birmingham, UK but the Credits page lists a team that contains the author (South American), a proof reader, two reviewers (South American) and a list of editors (India mostly).

After reading the Preface I was wondering what these people all did, for they surely can not be proud of the English used. Please don't get me wrong, it is English that is correct, but it is definitely English from a non-native speaker. This is a shame as it degrades the reading experience and is sometimes even down right annoying. I would expect proof readers, reviewers and editing teams to take more care with the final results.

That being said, the contents looks promising with chapters covering:

soft introduction to BPM
some graph programming and a first process
setup of the development enviornment (jBPM, JBoss Drools, JBoss ESB, Maven, MySQL, Eclipse and SVN)
jPDL
implementing an example process
persistence in jBPM
Human Tasks with an example
process variables
looking closer into some advanced features

My initial impressions and questions are:

I don't understand why all these technologies have been used in a jBPM Developer Guide (Drools, ESB, Maven, MySQL, Eclipse and SVN)
the author gives us "homework" in the first three chapters, but then it just stops until the ninth chapter, rather a shame
miss exception handling as an advanced feature?
not sure the author has experienced "life in the trenches" with jBPM?
why is the focus only on jBPM 3.x and nothing is said about jBPM 4.x, the only actively developed version of jBPM at the time of this books writing?

Well, it is always good to review something with some initial questions, so stay tuned as I explore the book further in the coming weeks.

Onwards to jBPM Developer Guide review part II
Onwards to jBPM Developer Guide review part III

2009 in review

eric@schabell.org (eric@schabell.org) — Thu, 31 Dec 2009 04:48:46 PST

It is that time of year, when Christmas has passed (did you get the things you wished for?) and the New Year is upon us. A time for reflection and appreciating the things we have achieved.

As I look back I tried to come up with a picture to put in this post that would reflect the leading theme in my year. It should come as no surprise, if you have been following my blog at all, that JBoss jBPM logo is the image that has guided my year!

I started 2009 still working at the SNS Bank, leading and implementing jBPM projects to put financial products on-line for her customers. I published many of these experiences and tried to lift the lid as much as one can from inside of a financial institution, even managing to post some code to this blog. Here is a bit of a review:

work on a state-proxy completed, a par repository, a custom jBPM exception framework and JBoss serialization
published several articles on Computable.nl: Out of work IT'ers, Open Source cost money, Dare to save with SmartIT, Companies have Open Source in their own hands and IBM integration of SUN
previewed some of the jBPM 4.x releases: 4.0 beta 1, 4.0 beta 2 and 4.1
have been asked to review the newly released jBPM Developer Guide
published in 2009 BPM & Workflow Handbook and received a Silver award for BPM excellence
attended conferences: JFall, Open Source Conference Amsterdam, Devoxx, Soa Symposium, CAiSE/PRET, Dutch JBoss Event, jBPM Community Day and attempted (who was I kidding?) to speak at Java One
taught two courses in Rome: BRMS and jBPM
attended a JBoss BRMS workshop in Atlanta, GA

All of this got the attention of Red Hat and I decided to join the team in May as a JBoss Solution Architect Benelux. It has been amazing to work inside the JBoss house, seeing the latest and greatest software rolling off the development blocks.

I was able to make some rather small contributions to some open source projects, with some translations for meebo.com, a small fix in jBPM 4.2 (can you find it?) which made the jBPM 4.3 release just before the end of 2009 and another patch is still waiting for evaluation in the jBPM 4.4 release.

On the cycling front, I picked up a new road bike, at the end of the year a winter mountain bike and made some great rides this year in several countries:

new bike
Veluwe ride
Limburg rides; climbing and in the hills
Uden ride
Oude Holleweg and Van Randwijckweg in Beek
Belgium Ardennes

The only sad item I have to mention was the trading in of my beloved 1987 Austin Mini, the end of an era for me with regards to Mini's.

Being healthy and happy, I wish you and yours all the best in 2010!

jBPM 4.3 released

eric@schabell.org (eric@schabell.org) — Wed, 30 Dec 2009 04:43:02 PST

The latest release posted on sourceforge includes my patch for a very small fix (but it is my first in the jBPM project!) listed here as shown in the release notes readme.html file included in the download:

Patch

[JBPM-2520] - The install build.xml is not reporting the new Signavio installtion target (patch attached)

A nice way to end 2009! ;-)

Book review: jBPM Developer Guide

eric@schabell.org (eric@schabell.org) — Mon, 21 Dec 2009 00:54:43 PST

I have been approached about doing a review of this book, which will be appearing soon. As soon as I receive an e-copy or preview copy in the mail I will be posting my impressions in detail.

The book is available here from PACKT publishing.

JBoss Enterprise Application Platform (EAP) deployment plans

eric@schabell.org (eric@schabell.org) — Thu, 10 Dec 2009 05:40:34 PST

To be honest with you, I have never heard of deployment plans before. I was aware of deployment descriptors, but not deployment plans.

A bit of searching turned up this bit of information:

Every J2EE application module must include an XML based deployment descriptor that provide configuration information for the asset as well as defining relationships to other components.

There are two types of deployments descriptors:

vendor neutral deployment descriptors (a.k.a deployment descriptors)
vendor specific deployment descriptor (a.k.a deployment plans)

Deployment descriptors are necessary but are not always sufficient to deploy an asset on your server. Deployment plans provides additional information to map declared resources names, ejb names, security roles, JMS roles (if any) to actual resources in the server. The deployment plans also contain specific server settings and configurations.

So we are looking at a vendor specific deployment descriptor file for the various application modules use. Now I was curious to those for JBoss, so dug around a bit and have come up with this overview.

Vendor neutral:
J2EE module file type Standard deployment descriptors
-------------------------------------------------------------------------------
Enterprise Application Archive (EAR) META-INF/application.xml
Web Application Archive (WAR) WEB-INF/web.xml
Jar containing Enterprise Java Beans (JAR) META-INF/ejb-jar.xml
J2EE Connector Resources Adapter Archive (RAR) META-INF/ra.xml
Enterprise Application Client Archive (JAR) META-INF/application-client.xml

JBoss specific (EAP):
J2EE module file type JBoss deployment plan
-------------------------------------------------------------------------------
Enterprise Application Archive (EAR) jboss-app.xml
Web Application Archive (WAR) jboss-web.xml
Jar containing Enterprise Java Beans (JAR) jboss.xml
J2EE Connector Resources Adapater Archive (RAR) ---
Enterprise Application Client Archive (JAR) jboss-client.xml

There you go, happy deployment planning!

A custom jBPM exception framework for jBPM 3.x

eric@schabell.org (eric@schabell.org) — Mon, 07 Dec 2009 10:06:00 PST

I have spent some time over the last few months (slowly, only one day a week) working on a jBPM exception handling framework. I wanted to present the use case and leave the exact details over to you as an exercise in Java coding. ;-)

The idea is that jBPM (here using 3.x supported versions from the Red Hat JBoss Customer Support Portal (CSP) provides the standard jBPM exception and that I want to also have the choice to apply a dynamically generated transition from the point of an exception that takes me to a custom exception flow. This custom exception flow is nothing more than a single decision that, based on the type of exception I have passed, will choose a path to one of the following:

task node (human task to evaluate the exception)
state node (retry using a timer to wait a bit before trying again)
any eventual node desired to process the exception

There are some fairly obvious benifits:

no longer just one handling for all your jBPM process exceptions
very extensible, just add new nodes into the exception handling process flow to provide new functionality
placing exception handling into an apart flow means you can deploy this once and use it with all of your deployed processes
provides for decisions, states and node exception handling. Transitions should not be doing anything exciting within my processes, if yours needs to you can extend this concept to these too.

The process flow diagram provided in this post shows the simple testing framework I used to enable this. All code snippets shown are simplified for this post. There is a global attribute that is checked for using our custom exception framework called 'useCustomExceptions'.

Decisions
For a decision node we need to implement the DecisionHandler from jBPM, so I do that in an AbstractDecisionHanlder that implements the decide() method and puts in an extra handleException() method as follows:

public String decide(ExecutionContext ctx) throws Exception {

  try {
         // pick transition from the decision handler.
         transitionName = chooseTransition(ctx); 
         getLogger().debug("Choosing transition " + transitionName);
  } catch (Exception ex) {
         if (useCustomExceptions) {
             getLogger().error("Handler threw exception.", ex);
             ctx.getNode().raiseException(ex, ctx);
         } else {
             getLogger().error("Handler threw exception.", ex);
             ctx.setException(ex);
             // use custom method to create dynamic transition.
             dynamicTransition = handleException(ctx);
         }
  }

  return transitionName;
}


// This method is provided in comment steps only, the rest
// is an exercise for you (I can not publish this code).
private String handleException(ExecutionContext ctx) {

  // Save the current node in the context to make a retry possible.
                
  // Make sure the transition to the Exception handling Node can be made.
                
  // Using handling node name for the transition name.
                
  return name_of_transition_leading_to_exception_handling;
}

Node
For a node we need to implement the ActionHandler from jBPM, so I do that in an AbstractActionHanlder that implements the execute() method. Furthermore I need to come up with a solution for the following issue that is unique to the jBPM 3.x node. When you enter a node, you have an on-node-enter event and when finished it will trigger the on-node-leave event which takes the transition that is assigned during the event on-node-enter event. This means using the Node.leave(some-transition) method will not work.

I got the reaction when I used this Node.leave(take-dynamic-transition-to-exception-handling) it worked fine until it entered the human-task wait state. At this point the originating node then continued onwards, taking the default transition (that was in the TransitionsList for the node) and merrily finishing the process flow. Even stranger, this was done on the same process id that was also assigned to some human task!

My solution is to provide a mechanism to do the following:

create the dynamic transition to custom exception handling for the node
add the dynamic transition to the TransistionsList for this node
put a copy of the TransistionList (without the new dynamic transition) into the jBPM Context
remove all transition entries from the TransistionsList except for the new dynamic one
use Node.leave() to follow the new dynamic transition
deal with exception handling
upon returning to the node after exception handling, pick up the transitions from the jBPM Context
fill the TransitionsList with those found in the jBPM Context
use Node.leave() to use the default

Some code to give you an idea with migrateTransitionsInNodeToContext which shows the transitions being migrated into the jBPM Context. I have left out the recovery of the transitions from the context, as it is trivial to reverse the process. To give you a bit of a hint, when you are in the exception handling process and decide it is time to go back to your originating node, you create a dynamic transition and fill the originating nodes TransitionsList from the jBPM Context. Here is some code snippets:

public final void execute(ExecutionContext ctx) throws Exception {

  try {
        if (ctx.getNode() instanceof State) {
           // process a state.
        } else {
   
           try {
  
              // do something in node.
           } catch (Exception ex) {
    
              if (useCustomExceptions) {
                   getLogger().error("Handler threw exception.", ex);
                   ctx.getNode().raiseException(ex, ctx);
              } else {
                   getLogger().error("Handler threw exception.", ex);
                   transitionName = handleException(ctx);

                   migrateTransitionsInNodeToContext(ctx);

                   // Move the process along.
                   if (!StringUtils.isBlank(transitionName) &&
ctx.getNode().hasLeavingTransition(transitionName)) {
                      ctx.getNode().leave(ctx, transitionName);
                   } else {
                       // Use the default transition.
                       ctx.getNode().leave(ctx);
                   }
              }
           }
        }
  } catch (Exception ex) {
      // do something
  }
}

/**
 * Use given context to migrate all transitions in the nodes list that
 * do not match the dynamic transition created for an exception.
 */
private void migrateTransitionsInNodeToContext(ExecutionContext ctx) {
  List existingTransitionsList = ctx.getNode().getLeavingTransitionsList();
  List removedExceptionTransitionList = new ArrayList();

  int i = 0;
  for (Transition transition : existingTransitionsList) {
    i++;
    if (transition.equals(transitionName)) {
      getLogger().debug("List item #" + i 
          + " is our dynamic tranition: " 
          + transition.toString());
    } else {
       getLogger().debug("List item #" + i + " tranition: " 
               + transition.toString() + ", migrating to context.");
       removedExceptionTransitionList.add(transition);
       getLogger().debug("List item #" + i + " tranition: " 
           + transition.toString() + ", removing from node transition list.");
       ctx.getNode().removeLeavingTransition(transition);
    }
  }

  if (!existingTransitionsList.isEmpty()) {
      // place existing transitions into context variable.
      String ctxStoredTranstionsName = 
           ctx.getNode().getName() + "_stored_transitions_list";
      ctx.setVariable(ctxStoredTranstionsName, removedExceptionTransitionList);
  }
}

State
For a state we work analogue to the decision node but within the extended abstract class that implements the jBPM ActionHandler. This is left as an exercise to the reader.

2009 Silver winner for Europe - Financial Crisis Front Lines: SNS Bank

eric@schabell.org (eric@schabell.org) — Tue, 24 Nov 2009 10:04:00 PST

I posted earlier that my chapter was nominated for the Global Awards for Excellence in BPM & Workflow. I received notificaiton as follows:

2009 Silver for Europe— Global Awards for Excellence in BPM & Workflow

This is to congratulate you on the judges voting for SNS Bank IT as the Silver winner for Europe. This is a significant achievement in the face of heavy competition. The Winners and Finalists of this year's awards will be published in the BPM Excellence in Practice 2010. The Excellence in Practice annual book series profiles the winning case studies each year of the new winners of the BPM and Workflow Awards with the emphasis this year on Impact, Innovation and Implementation in BPM Excellence in Practice 2009. The Digital Edition has just been released.

The award was announce live online via a web conference and an engraved trophy will be delivered to the SNS Bank. My thanks to all who made this work possible.

2009 BPM Excellence Awards Ceremony - join live webinar (1800 CET)

eric@schabell.org (eric@schabell.org) — Tue, 24 Nov 2009 07:05:12 PST

As posted earlier, there is an awards ceremony for a jBPM based submission today in a webinar on-line, to join just follow links below at 1800 hrs CET:

THE AWARDS CEREMONY

Date and Time: Tuesday November 24, 2009 at 12 noon EST.
(To check this time in your own region, go to http://timeanddate.com/worldclock/meeting.html)

Registration: About five minutes before the ceremony begins, click here to join http://bpm.acrobat.com/awards2009/ using your first and last name. You may be required to add the Adobe Flash plug-in if you do not have it.

PROCEDURE AT THE AWARDS CEREMONY:

Derek Miers, lead judge, will describe the major points of each case study after announcing the winner. Gold winners have been invited to contribute a brief 60-second speech highlighting important aspects of their implementation.

The winners of this year's awards will be published in the BPM Excellence in Practice 2010.
The Excellence in Practice annual book series profiles the winning case studies each year of the new winners of the BPM and Workflow Awards with the emphasis this year on Impact, Innovation and Implementation.

I look forward to seeing you at the Awards Ceremony and keep your fingers crossed for our submission!

Devoxx 2009 at the Red Hat stand

eric@schabell.org (eric@schabell.org) — Sun, 22 Nov 2009 02:00:35 PST

I was at Devoxx 2009 in Antwerp, Belgium from Wed, 18 November 2009 to Fri, 20 November 2009. Here is an overview of the photo's taken and the people I met. It was an exhausting experience, but very cool to mingle with so many developers out there creating and maintaining our projects. I especially wanted to thank the SEAM, Drools, RichFaces, Hibernate and jBPM teams for the beers and discussions we had.

Devoxx 2009

Open source conference Amsterdam 2009

eric@schabell.org (eric@schabell.org) — Sun, 22 Nov 2009 01:43:40 PST

Here are some pictures of the event held in the Amsterdam Arena. This was very international with lots of European and American visitors. I am including some of the photos I shot of the Red Hat team here in the Benelux and a few of the visitors we took onto the VIP terraces above the field (note the growing lamps used on the grass).