Someting and something else!

Towards getting Linux Expertise – Passed LPIC1 Exam 102 last week

2009-02-07T11:55:00.000-08:00

As I said earlier in my previous post, I prepared for a month for the LPIC1 Exam 102. I passed the exam last Monday with “comparatively” higher score than the previous Exam 101. I was really happy about it because I really prepared well this time... I don't want to fail such an entry level exam like this. Now, I am LPIC1 certified. I am happy that I am able to get the LPIC1 certification now. I checked the LPI web site about my certification, they confirmed it the next day on the web site that I am LPIC1 certified now.

Apart from the reason that I prepared well for this Exam, one another reason I think is the exam center is really good this time. They had this 19” flat screen monitor and it didn't itch my eyes like it did last time. Another reason is probably I slept very well before the exam day. Also, I reached the exam center 15 mins early and had been asked to wait for around 20 mins. I really took that time to relax ( I didn't touch my notes at that time).

More about the exam, I prepared from the book “LPI LINUX Certification in a nutshell” - 2nd Edition. This book is a valuable resource for the preparation. Along with this book, I used all the tutorials listed on the IBM Developerworks website. Also, one more book is from Alan McKinnon and Michel Bisson. You can do a quick search on google with the author names, you will get a pdf link. Also, I borrowed a book called “Linux for Dummies” and found interesting to read about some fundamental stuff described on that book.

There are totally 9 topics for the exam 102:

Kernel
Boot, Initialization, shutdown and runlevels
Printing
Documentation
Shells, Scripting, Programming and Compiling
Administrative tasks
Networking fundamentals
Networking Services
Security.

Please note the the LPI Exams Objectives are going to Change after April 2009, so please refer the LPI web site LPI.ORG for latest objectives if you read this after April 2009.

I have totally two laptops setup in my home. I installed Ubuntu 8.10, Fedora 10 and Windows XP in one of the laptop for the exam preparation. The other laptop runs Windows Vista. I need to get some other Linux flavor running on this Vista laptop soon.

I prepared Samba, Apache, Sendmail and DNS topics very well. Also I reviewed the complete Network fundamentals very well. Items like UDP, TCP, ICMP and IP are important from the exam perspective.

Also, iptables is important as well. If you are good with bash shell along with networking, it will be very easier to pass the exam.

Now, time to prepare for the Exam 201. I will write more about the preparation in coming week. Until then.

Vijay Chinnasamy

One step at a time towards getting Linux Expertise – Passed LPIC-1 Exam 101 today

2008-12-20T19:54:00.000-08:00

One step at a time towards getting Linux Expertise – Passed LPIC-1 Exam 101 today

I have been using Linux for at least more than 10 years now, however I am not an expert at all (I realised this especially during the exam I gave for LPIC-1 101 today morning at a Prometric center in Tampa, Florida). I am just a beginning UNIX system administrator try to learn and understand how it works. I am interested to do a IT certification in Linux. There are few Linux certifications available in the market. However, I chose LPIC due to its vendor neutral offer. Other certifications are normally vendor specific...

The exam was difficult than I expected. Until today morning, I thought it will be an easy exam, and will be a cake walk for me. But it is not.The exam was comparitively difficult than I thought, with "fill in the blanks" questtions, specific command options asked etc. I was really humiliated by not knowing some of the answers for sure. The questions were tricky. However I PASSED the 101 exam today.. So I am planning to write my lessons learned here and planning more for my 102 exam in next few weeks...

I used following study materials for the 101 exam:

LPI Exam in a nutshell
IBM DeveloperWorks Study Material
LinuxIT Tutorials

Some practice tests I tried:

http://www.gnosis.cx/publish/tech_index_lpi.html
http://www.linux-praxis.de/lpisim/lpi101sim/index.html
Practice Test on the LPI Exam in a nutshell book

As of December 2008, the LPIC1 101 exam objectives are divided into five topics. The objectives are expected to be changing in coming months. Please check the LPI website for the latest information. For my exam, the five topics are:

Hardware & Architecture
Linux Installation & Package Management
GNU & Unix Commands
Devices, Linux Filesystems, Filesystem Hierarchy Standard
The X Window System

I thought I can easily get 100% score on the GNU & unix Commands section. But no luck....! There are questions which make you to think, unless you are sure about it, it is not easy to pick the correct answer(s).

I am planning to write more about how to prepare for this exam - Good news is there are a lot of tutorials on the internet - this, sometime makes it tougher - I made a mistake of not taking notes during my preparation. I should be preparing notes for my 102 exam for sure.

My preparation started with installing Linux Operating systems on my Dell Latitude laptop. I re-partitioned the hard disk and installed one Redhat based system (Fedora 10) and a debian based system (Ubuntu 8.10) along with Windows XP Professional. I was running GRUB on them.

I am planning to write more about my lessons learned on coming weeks. until then!!!

Vijay Chinnasamy

Episode 02: Peoplesoft Web Services with Peopletools 8.49

2008-04-06T09:09:00.000-07:00

Episode 02: Peoplesoft Web Services with Peopletools 8.49

There are many features that are important in using Web Services. Without any doubt, Peoplesoft Web Services provides most of the features which relate to integrating with other application using Web Services Technology…To understand Peoplesoft Web Services, an introduction to service- oriented Architecture and related components are important.

Service- Oriented Architecture (SOA) provides the theory basis for understanding the Web Services Concept. There are three related components that are basic in SOA-
1. Service Requestor
2. Service Registry
3. Service Provider

A Service Requestor (Example: Book an airline reservation) submits an request to service registry. A Service Registry basically will have all the list of Services and their service provider. The Service Requestor finds the services from service registry and contacts to service provider directly for its transaction processing.

Starting with Peopletools 8.48 and later some of the Integration Broker terminologies are changed to reflect the integration based on Web Services & Service- Oriented Architecture model. Let’s discuss the Web Services technology stack to compare with Service-Oriented Architecture Theory.

Starting with Peoplesoft 8.48/8.49, Integration with any third-party application using Web Services is more easy to setup than the previous versions. Integration uses the mostly accepted Web Services Technology using SOAP, XML, WSDL, UDDI etc. The communication uses either HTTP or HTTPS so there are no other complicated protocols involved for communication purposes.

Any third-party application that is requesting a service contacts the Gateway URL which will provide the WSDL file. WSDL is an acronym for Web Services Description Language. A WSDL file is an XML file that provides the list of services provided, the service provider details, and the service descriptions.

Then, the second part of intgration. The third-party application needs to parse the WSDL file and process them - Development Work. Finally the Service transaction takes place. We will talk more about Peoplesoft Specific setup with an Example in coming weeks. Until next Time - Vijay Chinnasamy, PMP

Episode 01: Peoplesoft Web Services with Peopletools 8.49: An Introduction

2008-03-08T21:26:00.000-08:00

Episode 01: Peoplesoft Web Services with Peopletools 8.49: An Introduction

Integrating Peoplesoft applications with other applications are one of the most interesting topic for an individual working with Peoplesoft based applications. I can’t comment about others but it is so for me. Peoplesoft Web Services provides a great way for integrating peoplesoft-based applications with other web-based applications. And, you are right; Peoplesoft Web Services is my topic for most of my next episodes here.

To start knowing about Peoplesoft Web Services, you have to get some basic understanding of what is Web Services first. Web Services are an important evolution that you must understand first. As you know already, IT is a fast changing world. To understand Peoplesoft web services, an introduction about some of the related topics are important; for example, SOA, SOAP, XML, WSDL, UDDI etc.

I have some confusion where to start first. There are many ways for you to understand about web services. If you know something about how Internet works, there is an easier way to learn this. If you know something about how traditional applications work, there is another way. If you know, HTML, Javascript and other related languages like Java, PHP etc, there is another way to learn this.

I am going to tell how I learned it. To start with, I studied Chemical Engineering in the college. Unfortunately, I never had a chance to apply (in a manufacturing or an industrial environment) what I learned during my four years of engineering studies. Instead, the very first year I finished my college, I became a web developer doing all HTML, Perl, PHP, Apache, MySQL et all (during 1999). That gave me a good feeling of how the web, I mean the internet, works.

Now, I assume, you all know what is HTML, what is JavaScript, what is CSS. If you don’t, I would recommend to stop reading from here on. I don’t want to get a bad name from you not to understand this. Actually, Web Services are needed to be dealt with separate books. There are number of books written about Web Services. You may need to pick one before learning about Peoplesoft web services.

As per W3C Web Services Glossary Definition, A Web Service is considered a “software system designed to support interoperable machine-to-machine interaction over a network”. Oh… sorry for confusing you suddenly with technical jargon. If we look at this definition closely, we can note that a Web Service is a software system, just an example like a Ticket Reservation System. A Web Service that offers software application that can fit into our day-to-day requirements… Astonishing!!!

We will look into more closely about Web Services and How Peoplesoft integrates this great feature into its Peopletools capability. There are a number of ways we can exploit this feature for our own needs. We will look into all these in our next episodes. Until Next time – Vijay Chinnasamy, PMP

Take 3: Jolt Session Pooling Covered....

2008-01-24T18:17:00.000-08:00

Take 3: Jolt Session Pooling Covered....

Before reading this entry (always a friendly warning first!), please read about my two blog entries that I posted earlier. This entry is kind of closure to my previous topic "Jolt Session Pooling". If you still have decided to read this one, you cant complain about not able to understand this one....

In our last blog entry, we talked about Jolt Session Pooling. As I stated earlier, Jolt Session Pooling is enabled by default in Tools Version 8.48 and later. Considering this new feature(!), there are some things that are changed due to this parameter single change starting with Tools 8.48 and later....

Also, we talked about the sevlets (like psc, psp etc) that are having 'definitions" in the web.xml file (under DOMAIN/PORTAL/WEB-INF directory). So, back to our main point.. why JoltPooling needs to be disabled for all the servlet entries in the web.xml file to resolve the "download to excel" button to work... Probably you have guessed it already.

The key point here is, when Jolt Session Pooling is enabled, the session is shared across all the servlets. The existing sessions are shared across multiple servlets within weblogic server. This is supposed to be provide good performance results. There are no dedicated sessions. As of now, I know some of the effects of this change in 8.48 environment:

1) "Download to Excel" button not working

2) Tuxedo is unable to list the online users on the system

3) "View Attachment" is not working

If you know anything else due to this "Jolt Session Pooling" enabled option causing in Peoplesoft, please write on the comment below for me to know and learn. My policy is to share the knowledge and feel free to learn. :)

To know more about Jolt and Weblogic, I would recommend you to read the BEA documentation about "Using BEA Jolt with BEA Weblogic Server" Guide. I am going to write some new things going forward... One of my favorite: Inter Process Communication in the Unix System and Peoplesoft. Check this blog later.. Until Next time - Vijay Chinnasamy PMP

2008-01-17T19:11:00.000-08:00

Take 2: Jolt Session Pooling Continued....

In our last blog, we talked about Jolt Session Pooling. That was kind of introduction to this concept I suppose. I am now going much deeper into this parameter to understand how this parameter works with Peoplesoft context (also I am interested to know more about this parameter anyway!)...

A quick look at the web.xml file at PORTAL/WEB-INF folder can
give you a list of servlets that Peoplesoft application uses: Some of them
are:

xmllink

PSAttachServlet

psreports

SchedulerTransfer

SyncServer

monitor

ppmi etc...

I am not going into each and every servlet that Peoplesoft uses and their details. That is out of scope for my explanation here. And, primarily because, I do not know about them neither... However an overall understanding of this will definitely help us to understand the underlying architecture behind the Peoplesoft Internet Architecture.

For each and every servlet that Peoplesoft uses, there exists a definition at web.xml file. For simplicity sake, this file can be treated as Servlet Configuration File and it is an XML file by nature. If you work with weblogic and Java J2EE, they call this file as Deployment Descriptor Elements. I find it hard to remember that way. So, just to keep things easy, consider this web.xml file as Servlet Configuration File created as part of application deployment...

We are talking here for Peoplesoft technology. We dont need that much gory details to know about weblogic (we need to know some basics!). Just basics. A weblogic server has many servlets that is used for processing requests. A servlet basically connects to the Tuxedo using a session pool manager, which assigns a session based on availablity etc. This session is, then, connecting to the Tuxedo system (application server) using Jolt Server.

So, back to our main point.. why JoltPooling needs to be disabled for all the servlet entries in the web.xml file to resolve the "download to excel" button to work... Probably you have guessed it already. Check this blog later.. Until Next time - Vijay Chinnasamy PMP

Peoplesoft Jolt Session Pooling

2008-01-15T17:35:00.000-08:00

Okay, long time no see! I am back. I had some project and personal commitments that I needed to complete during last year. One of my project commitment was, obviously due to the reason that I moved to a new project. Also, coincidently I moved to a new location in another country which added some more complications with my new project assignment...

I had a goal last year (2007) to become a certified PMP. PMP is an acronym for Project Management Professional offered by PMI (Project Management Institute). I took the training from my company starting of the year 2007. And eventually I have become PMP after spending quite a considerable time. That was my personal commitment that delayed me from writing in this blog.. So, long story short, I am going to write again in this blog. All that I know about Peoplesoft and Unix (Dont laugh, I will try!).

We had a situation recently in our UAT environment. The "download to Excel" button is not working. You should be aware of what this "Download to Excel" button I am talking about. For those who are unable to guess, here it is. It is a small image, just like an excel sheet, that will be shown on the right corner of the any tabular output from Peoplesoft application ( Example Process monitor, Reports etc).

I started doing some research (still!). You know where to start first. You guessed, right, Peoplesoft Customer Connection. They recommended to try disabling JoltPooling in Web Server. This directive is available in web.xml file for the weblogic web server.

Starting with Tools 8.48, Jolt Pooling is enabled by default. What does this mean? Let me explain this from the scratch. As you are aware, web server makes a connection to app server using Jolt. If you enable Jolt Session Pooling , the user connections between web server and app server are simply shared. This setting is expected to minimise system resources by sharing the user connection by pooled sessions...

Web.xml file is an xml file that has directives for all the peoplesoft servlets that the web server uses ( for example, psp, psc etc). Every servlet is set to JoltPooling set as true by default starting with Peopletools Version 8.48. All we did was, disabled JoltPooling on all of these servlets. And this issue is resolved.

Is the issue really resolved? Not exactly, I will say. We still need to find why Jolt Session Pooling needs to be disabled to make "Download to Excel" button to work. Mystery continues.... Until next time.

- Vijay Chinnasamy PMP