Search results matching tags 'Concepts', 'Web', 'Link Lists', 'Cloud', and 'Design'

Windows Azure End to End Examples

BuckWoody — Tue, 29 May 2012 13:45:59 GMT

I’m fascinated by the way people learn. I’m told there are several methods people use to understand new information, from reading to watching, from experiencing to exploring.

Personally, I use multiple methods of learning when I encounter a new topic, usually starting with reading a bit about the concepts. I quickly want to put those into practice, however, especially in the technical realm. I immediately look for examples where I can start trying out the concepts. But I often want a “real” example – not just something that represents the concept, but something that is real-world, showing some feature I could actually use.

And it’s no different with the Windows Azure platform – I like finding things I can do now, and actually use. So when I started learning Windows Azure, I of course began with the Windows Azure Training Kit – which has lots of examples and labs, presentations and so on. But from there, I wanted more examples I could learn from, and eventually teach others with. I was asked if I would write a few of those up, so here are the ones I use.

CodePlex

CodePlex is Microsoft’s version of an “Open Source” repository. Anyone can start a project, add code, documentation and more to it and make it available to the world, free of charge, using various licenses as they wish. Microsoft also uses this location for most of the examples we publish, and sample databases for SQL Server.

If you search in CodePlex for “Azure”, you’ll come back with a list of projects that folks have posted, including those of us at Microsoft. The source code and documentation are there, so you can learn using actual examples of code that will do what you need. There’s everything from a simple table query to a full project that is sort of a “Corporate Dropbox” that uses Windows Azure Storage.

The advantage is that this code is immediately usable. It’s searchable, and you can often find a complete solution to meet your needs. The disadvantage is that the code is pretty specific – it may not cover a huge project like you’re looking for. Also, depending on the author(s), you might not find the documentation level you want.

Link: http://azureexamples.codeplex.com/site/search?query=Azure&ac=8

Tailspin

Microsoft Patterns and Practices is a group here that does an amazing job at sharing standard ways of doing IT – from operations to coding. If you’re not familiar with this resource, make sure you read up on it. Long before I joined Microsoft I used their work in my daily job – saved a ton of time. It has resources not only for Windows Azure but other Microsoft software as well.

The Patterns and Practices group also publishes full books – you can buy these, but many are also online for free. There’s an end-to-end example for Windows Azure using a company called “Tailspin”, and the work covers not only the code but the design of the full solution. If you really want to understand the thought that goes into a Platform-as-a-Service solution, this is an excellent resource.

The advantages are that this is a book, it’s complete, and it includes a discussion of design decisions. The disadvantage is that it’s a little over a year old – and in “Cloud” years that’s a lot. So many things have changed, improved, and have been added that you need to treat this as a resource, but not the only one. Still, highly recommended.

Link: http://msdn.microsoft.com/en-us/library/ff728592.aspx

Azure Stock Trader

Sometimes you need a mix of a CodePlex-style application, and a little more detail on how it was put together. And it would be great if you could actually play with the completed application, to see how it really functions on the actual platform.

That’s the Azure Stock Trader application. There’s a place where you can read about the application, and then it’s been published to Windows Azure – the production platform – and you can use it, explore, and see how it performs.

I use this application all the time to demonstrate Windows Azure, or a particular part of Windows Azure.

The advantage is that this is an end-to-end application, and online as well. The disadvantage is that it takes a bit of self-learning to work through.

Links: Learn it: http://msdn.microsoft.com/en-us/netframework/bb499684 Use it: https://azurestocktrader.cloudapp.net/

Windows Azure Use Case: Hybrid Applications

BuckWoody — Tue, 22 Feb 2011 19:44:09 GMT

This is one in a series of posts on when and where to use a distributed architecture design in your organization's computing needs. You can find the main post here: http://blogs.msdn.com/b/buckwoody/archive/2011/01/18/windows-azure-and-sql-azure-use-cases.aspx

Description:

Organizations see the need for computing infrastructures that they can “rent” or pay for only when they need them. They also understand the benefits of distributed computing, but do not want to create this infrastructure themselves. However, they may have considerations that prevent them from moving all of their current IT investment to a distributed environment:

Private data (do not want to send or store sensitive data off-site)
High dollar investment in current infrastructure
Applications currently running well, but may need additional periodic capacity
Current applications not designed in a stateless fashion

In these situations, a “hybrid” approach works best. In fact, with Windows Azure, a hybrid approach is an optimal way to implement distributed computing even when the stipulations above do not apply. Keeping a majority of the computing function in an organization local while exploring and expanding that footprint into Windows and SQL Azure is a good migration or expansion strategy.

A “hybrid” architecture merely means that part of a computing cycle is shared between two architectures. For instance, some level of computing might be done in a Windows Azure web-based application, while the data is stored locally at the organization.

Implementation:

There are multiple methods for implementing a hybrid architecture, in a spectrum from very little interaction from the local infrastructure to Windows or SQL Azure. The patterns fall into two broad schemas, and even these can be mixed.

1. Client-Centric Hybrid Patterns

In this pattern, programs are coded such that the client system sends queries or compute requests to multiple systems. The “client” in this case might be a web-based codeset actually stored on another system (which acts as a client, the user’s device serving as the presentation layer) or a compiled program. In either case, the code on the client requestor carries the burden of defining the layout of the requests.

While this pattern is often the easiest to code, it’s the most brittle. Any change in the architecture must be reflected on each client, but this can be mitigated by using a centralized system as the client such as in the web scenario.

2. System-Centric Hybrid Patterns

Another approach is to create a distributed architecture by turning on-site systems into “services” that can be called from Windows Azure using the service Bus or the Access Control Services (ACS) capabilities. Code calls from a series of in-process client application. In this pattern you move the “client” interface into the server application logic.

If you do not wish to change the application itself, you can “layer” the results of the code return using a product (such as Microsoft BizTalk) that exposes a Web Services Definition Language (WSDL) endpoint to Windows Azure using the Application Fabric. In effect, this is similar to creating a Service Oriented Architecture (SOA) environment, and has the advantage of de-coupling your computing architecture. If each system offers a “service” of the results of some software processing, the operating system or platform becomes immaterial, assuming it adheres to a service contract.

There are important considerations when you federate a system, whether to Windows or SQL Azure or any other distributed architecture. While these considerations are consistent with coding any application for distributed computing, they are especially important for a hybrid application.

Connection resiliency - Applications on-premise normally have low-latency and good connection properties, something you’re not always guaranteed in a distributed and hybrid application. Whether a centralized client or a distributed one, the code should be able to handle extended retry logic.

Authorization and Access - In a single authorization environment like a Active Directory domain, security is handled at a user-password level. In a distributed computing environment, you have more options. You can mitigate this with using The Windows Azure Application Fabric feature of ACS to make the Azure application aware of the App Fabric as an ADFS provider. However, a claims-based authentication structure is often a superior choice.

Consistency and Concurrency - When you have a Relational Database Management System (RDBMS), Consistency and Concurrency are part of the design. In a Service Architecture, you need to plan for sequential message handling and lifecycle.

Resources:

How to Build a Hybrid On-Premise/In Cloud Application: http://blogs.msdn.com/b/ignitionshowcase/archive/2010/11/09/how-to-build-a-hybrid-on-premise-in-cloud-application.aspx

General Architecture guidance: http://blogs.msdn.com/b/buckwoody/archive/2010/12/21/windows-azure-learning-plan-architecture.aspx