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This 4th and last part contains best practice No.7 ~ 10. To be notified for future posts, feel free to subscribe to this feed, and follow me at Twitter.

#7 Levarage vApp

vApp is a new addition to vSphere. It’s essentially a group of VMs that work together as a solution. You can manage them as a basic unit like a VM. It provides you higher level granularity for resource allocation and management.

This is an ideal container for your application if you have multiple virtual machines involved. They may or may not form a cluster, but are bundled together for a same goal.

The vApps are not only easily managed by the vSphere, but also imported and export as a bundle. Therefore you can easily move it without worrying what should be included while copying it.

VMware provides tools like VMware Studio using which you can create and configure vApps easily. The VMware Studio has Web based console, customization and build engine, build process automation with CLI (command line interface).

Other alternatives include:  Read more... (1417 words, estimated 5:40 mins reading time)

Just read part of the book Founders At Work over the weekend. Although I haven’t decided to be a founder of a startup company, I found the stories there are trully inspirational. You can read part of the book at Google book.

One interview with Hotmail cofounder Sabeer Bahatia is very interesting with his thoughts on the differences of software and hardware designers:  Read more... (468 words, estimated 1:52 mins reading time)

This 3rd part contains best practice No.4 ~ 6. To be notified for the rest, feel free to subscribe to this feed, and follow me at Twitter.

#4 Scale Applications as Needed

Most time, people think scalability is to handle more workload when needed. This is true, but not enough. A truly scalable system should scale back. This is how you will save money. This is equally important as the first case where you get more revenue by serving more traffic.

There are different ways to scale:

• Up and down. This is unique in virtualized environment in which you adjust the memory or CPU allocation and use more or less of them instantly.
• Out & in. This means you include more machines either physical or virtual into your application.

You have to think over several architecture decision points:  Read more... (1601 words, estimated 6:24 mins reading time)

This second part contains best practice No.1 ~ 3.

＃1 Move Up to Higher Level Software Stack 

“If I have seen a little further it is by standing on the shoulders of Giants.”

 Isaac Newton

Modern software development is all about leverage. You don’t want to build everything from bottom up. Whatever “giant shoulders” you can leverage, you should do so. Remember the keyword here is “giant shoulders.” You got to be selective on what is “a giant” and what is not, for the best quality of your system. Your application’s quality is a function of that of the systems underneath it.

The typical “giant shoulders” includes middleware, high level programming languages, tools. By leveraging these, you should expect your applications portable, and with much less code and higher developer productivity. The portability is very important when you want to deploy your applications in federated cloud environment.

I posted a short article after the cloud demo in VMworld 2009 keynotes. It’s reposted at SpringSource blog. The article introduced “DIY PaaS” concept which you could have a higher level of development platform inside your enterprise in a similar way as would you get from vendors like Google, but without vendor lock-in.

The “DIY PaaS” does not require you to use any specific platforms, middleware or framework. You could use any existing combination of systems on top of Java, .Net, Python, PHP. For example, you could use Java with Spring framework for building your web applications or enterprise integration frameworks. The choice is really yours, not of any vendors. When making a decision, you want to consider various factors like your team’s expertise and preference, total cost of software licenses, design constraints posted by for example existing investments on particular software.

Having decided the combination of software stack, you want to pack them into virtual machine templates that can be re-used by various teams. If you have multiple combinations, you can have multiple virtual machine templates in your catalog.

In general, you want as few templates as possible. Why?

Having less VM templates means less effort to build them, to manage, to upgrade, and to test. This might not seem like a big deal but could become a big deal in a longer term when you have to maintain multiple versions of these templates at the same time.

It also means less storage. vSphere has a special technology called linked clone. The new virtual machine doesn’t fully clone the disks, but links back to the template. If you have least templates, you can have a huge saving on the disk space. High quality storage can be very expensive.

Last but not least benefit is less memory. vSphere has memory page sharing technology which keeps one copy of same page contents, and converts others as pointers to the single copy. It’s only possible when you have identical memory pages. When you have virtual machines cloned from a same templates, the chance of identical memory pages increases dramatically.

There are several techniques to keep the least number of virtual machine templates:  Read more... (1735 words, estimated 6:56 mins reading time)

Overview

With more data centers running on purely virtualized systems, more applications are therefore running on top of virtualized environment than ever before. These virtualized systems are interconnected with each other and become a cloud platform. Virtualization is the pre-requisite and starting point of the cloud computing at the IaaS level.  Read more... (568 words, estimated 2:16 mins reading time)

With SpringSource being part of VMware family, getting a Spring training is certainly a lot easier than before. For one thing, my boss doesn’t need to pay for it.:-)

I just finished my 4-day training starting from this Tuesday. It’s been pretty exhausting given that I had to get up before 7AM to match the central time. But what’s learnt worth the effort.

The coverage of the training includes:  Read more... (192 words, estimated 46 secs reading time)

Just came back from a SDForum meeting organized by its emerging technology SIG. The topic was about the 4 languages in the title. It’s not much about any emerging technology per se, but pretty controversial among the developers.

The organizers invited four panelists and one moderator:

• Clojure advocate – Amit Rathore, author of the forthcoming “Clojure In Action”
• Go advocate – Robert Griesemer, Google, co-author of Go
• Scala advocate – David Pollak, lead author of Lift
• Ruby advocate – Evan Phoenix, lead developer of Rubinius, a high performance Ruby VM
• Moderator – Steve Mezak, co-chair of the SDForum Software Architecture and Modeling SIG, author of Software without Borders

Each of the panelists had 10 minutes of introduction of the language in the first part. Then, they all answered questions ranging from language strength/weakness, library/tool/IDE support, application framework, advice on migrating existing codebase, to how these languages compare to each other.

Here are introductions from the languages’ homepages. See if you can map them to the languages.  Read more... (628 words, estimated 2:31 mins reading time)

WordPress is a great blogging software. I am very happy with it except that it does not have nice built-in support to include source code, which an absolutely needed feature for me.

Given the rich set of plug-ins WordPress has, I know there must be some plug-in there already. Today I spent a little time on research. After trying several plug-ins, I decided to use Google Syntax Highlighter for WordPress. You can check out how it looks like as follows.  Read more... (351 words, estimated 1:24 mins reading time)

In my previous blog, I talked about the object model of the vSphere API. Many people like the UML diagram that illustrates how the managed objects are inherited from each other.

Following that blog, I will introduce the object model of the open source Java API that is built on top of the Web Services, as well as some key design decisions I made while designing the API.

The following UML diagram is extracted from the overall model but adds much more details with properties and methods. If you can understand this diagram, you can then easily understand all other managed object types.  Read more... (568 words, 2 images, estimated 2:16 mins reading time)

I mentioned the vSphere API self paced lab at PEX in my previous blog. Not all the people who are interested in learning the API made it to PEX last month. A reader asked me when it can be online in his comment.

Here is the VI Java API part in the tutorial. We had the environment set up all together for you in the PEX lab including the Eclipse and all the related jar files. So it’s very easy to get started there. Without going to PEX, you need to do something extra by yourself. But that is not too hard at all. I promise it won’t take you much time at all. To get the basic one done, you probably need 5 to 30 minutes depending on your familiarity with Java.

Ready to learn?  Read more... (1261 words, 1 image, estimated 5:03 mins reading time)