Random Thoughts

In my earlier blog post I shared my experiences taking SOA Architect Certified. In this post, I will shed light on the SOA Design & Architecture Lab Exam (S90.09).

The S90.09 lab is a two hour exam that requires you to answer twenty scenario based complex design problems. Each question in this exam has a scenario and a problem statement. The passing score for this exam is 60%. So you need to get 12 of the 20 questions correct. To successfully pass the exam, you need to apply all the concepts, terminology and patterns that you have learnt while preparing for the previous four exams.

To better understand the types of questions you can expect I have created two example scenario questions below:

Question 1

Service Consumer A needs to send a message to Service A. To successfully complete the request, Service A needs to send the message to Service B. Upon receiving a response from Service B, Service A computes a response and sends the message back to Service Consumer A.

Service Consumer A sends the message in XML format based on Schema X. However Service A only accepts XML messages based on Schema Y. Also, Service B is a legacy service and only communicates using CSV format. What needs to be done to ensure a successful message transfer?

A. The Contract Centralization pattern can be applied so that Service A and Service B accepts messages using Schema X.
B. The Data Format Transformation pattern can be applied between Service A and Service B so that messages can be converted between XML and CSV. The Data Model Transformation pattern can be applied so that messages from Consumer A can be processed by Service A and vice versa.
C. The Official End Point pattern can be applied to create a standardized XML schema to be used by all participating services and consumers
D. None of the above answers

Question 2

The figure below shows a Service Composition Architecture where Service A communicates with Service B and Service C. Service B uses Database A which is a shared database.

It has been brought to your attention that there has been degradation in the performance of this composition. After some analysis, it has been found that Service C has become part of several other compositions and is being heavily used. This has caused Service C to become unreliable. The load on the shared database has also increased severely causing Service B to become unstable. How can this Service Composition Architecture be changed to improve performance?

A. The Service Autonomy pattern can be applied to Service C to make it more reliable. To address Service B’s instability, the Redundant Implementation pattern can be applied.
B. The Service Data Replication pattern can be applied to Service B by giving a dedicated database that has a copy of Database A. The Redundant Implementation pattern can be applied to Service C to make it more reliable
C. The State Repository pattern can be applied to Service A so that it can store Service A’s data while it waits for responses from Service B and Service C.
D. None of the above answers.

I recently got my SOA Architect Certification from Aritura/SOASchool.com and considering the lack of information about the certification, I thought of sharing my experiences in this blog post.

Exam Overview

To be a Certified SOA Architect, you are required to pass the following five exams:

• Fundamental SOA & Service Oriented Computing – S90.01
• SOA Technology Concepts – S90.02
• SOA Design & Architecture – S90.03
• Advanced SOA Design & Architecture – S90.08
• SOA Design & Architecture Lab – S90.09

The time allowed for the first four exams is an hour and the final Lab is a two hour exam. All these exams can be taken at any authorized Prometric center. Like most Prometric exams, the score is provided immediately at the end of the exam. Once you complete two of the above five exams, you will become a Certified SOA Professional and will receive a SOACP certificate in mail.

Exam Details

Here is a high level overview of the five exams and their passing score.
Fundamental SOA & Service Oriented Computing – This exam tests the fundamental SOA terminology and concepts. If you are serious about SOA, like Thomas Erl mentions in this article, the topics required for this exam must become a second nature to you. The exam itself has 50 multiple choice and True/False questions. The passing score for this exam is 80% (40 of 50 questions).

SOA Technology Concepts – This exam tests concepts such as XML, XML Schemas, Web Service Contracts and WS-* stack. The exam has 50 multiple choice and True/False questions. The passing score is 78% (39 of 50 questions).

SOA Design & Architecture – This exam tests concepts surrounding services, service roles, service compositions with a heavy emphasis on the eight service orientation design principles. The exam has 50 multiple choice and True/False questions. The passing score is 80% (40 of 50 questions).

Advanced SOA Design & Architecture – This exam tests an understanding of design patterns in a SOA environment. To pass this exam, you need a solid understanding of Service Inventory Design Patterns, Service Design Patterns, Composition Design Patterns, ESB Patterns and Orchestration Patterns. Like the above three exams, this exam has 50 multiple choice and True/False questions. The passing score is 78% (39 of 50 questions).

SOA Design & Architecture Lab – This exam is heavy application based and tests the application of SOA concepts and design patterns. As part of the exam, you will be asked 20 scenario based questions. The passing score is 60% (12 of 20 questions). I am planning to post a separate blog with more details about this exam.

Exam Preparation

Arcitura/SoaSchools.com offers module courses that correspond to each exam. I took their five day WebEx of SOA Architect Certification training. After registering for the training, I received five module booklets and three books. Another good thing about taking the training is that we get exam vouchers at a discounted price.

After my training, I heavily used the booklets to prepare for the exams and referred to sections in the books. I took Exam 1 followed by Exam 3 which I heavily recommend as these two exams share concepts. Since the lab exam is more application of concepts learnt during previous exams (4 and 3 more specifically), I recommend not delaying it for a long time. Also, when taking the exam I noticed that if I click on the text of an answer it gets selected. If I were to click on the text again, it deselects it. If you are like me and click on the screen a lot while reading, be careful when reviewing your answers. You might accidently unanswer a question.

Conclusion

It has been an interesting journey taking these five exams. I feel good about scoring a 98% in the first exam and 100% in the rest of the exams. To conclude, this is truly a vendor neutral certification and it helped me solidify my existing SOA experience.