Article

Published: September 2010

Introduction

Microsoft has adopted a "we’re all in" strategy for thecloud. As part of this strategy, MSIT is migrating Microsoft.com to the cloudvia Windows Azure. SXP is one of the first technologies that MSIT has built anddeployed in the cloud by using Windows Azure. This article focuses on thedecisions that the SXP team made when creating the Windows Azure-based service.The article discusses the many advantages that Windows Azure provides and alsodiscusses lessons learned.

The Video Showcase Site on Microsoft.com

The VideoShowcase site on Microsoft.com hosts more than 8000 videos that assistMicrosoft customers in their search for information about products andservices. The marketing agencies that Microsoft works with use the site as avideo repository. The typical video is four to five minutes long. Customersview and learn from the video content and can comment on, rate, and sharevideos with their friends and colleagues on other social media channels andsites. The goal is to match customer intent with Video Showcase content and tocreate a sense of community and interest in Microsoft products.

The user experience for the site was developed withMicrosoft® Silverlight® technology. The Video Showcase site previously used athird-party on-premises solution to manage comments and ratings, to filter outprofanity and spam, and to do site moderation. This solution used blogs andblog posts to enable comments. Although the solution worked, it was hard to understandand explain. Maintenance costs were high and there were also issues related to upgrades,scalability, performance, and availability. Also, the business intelligence (BI)and information related to ratings and comments were either difficult to accessor not available at all. For these reasons, MSIT developed SXP, which isessentially a platform as a service (PaaS).

To learn more about the Video Showcase site, visit http://www.microsoft.com/showcase/en/US/default.aspx.

The Social eXperience Platform

SXP is a multi-tenant Web service that enables socialmedia capabilities across Microsoft.com. SXP’s first tenant is the VideoShowcase site. Customers can use the SXP Windows Azure-based service to managecomments and ratings, and to filter out profanity and spam. SXP provides theability to comment on or rate anything, including Web pages, news stories,videos, blog posts, and so on. As long as a unique ID can be assigned, userscan comment on or rate the item. The SXP team manages comments and filters viathe SXP Moderation Tool (built with Silverlight), which is also available via WindowsAzure.

SXP also provides a Really Simple Syndication (RSS) feedaggregation, grooming, and publication service to all Microsoft.com sites. Thisservice enables marketing site managers to easily manage and subscribe torelevant content across both desktop computers and mobile devices.

The SXP service is a back-end service for comments andratings; it is not the front-end Web server. The service does not host thevideos (they are hosted on MSN® Video Web Services) and does not host the HTMLthat users see on the screen.

SXP Architecture

The SXP solution takes advantage of the best of bothon-premises and cloud-based technologies. SXP runs on Windows Azure and the SQLAzure™ Database, but the Video Showcase Web servers are standard Microsoft.comservers running in Microsoft’s internal data center. This combination of technologiesenabled the SXP team to quickly create a solution with a high level ofinteroperability that adheres to the security and governance requirements thatare typical of a large enterprise.

Figure 1 shows the SXP architecture.

Figure 1. SXP architecture

SXP Web Services. The bulk of the work occurs inthe SXP Web Services—a Representational State Transfer Service (REST) runningon the Microsoft Visual Studio® 2010 development system and Microsoft .NET 3.5.SXP Web Services is a single Web role that runs on three medium instances. The SXPteam chose three instances to provide the high availability and scalabilitynecessary for an enterprise Web site the size of Microsoft.com. The servicecurrently runs at about 5 percent utilization, so it has a lot more capacitythan it needs. As the service brings on more partners, the team expectsutilization to increase. Windows Azure provides nearly unlimited scalabilityfor future growth.

The service is multi-tenant, allowing any sub site onMicrosoft.com to use the social capabilities of SXP. The SXP team accomplishesmulti-tenancy by creating a separate SQL Azure database for each tenant tostore comments and ratings. The team chose this approach to take advantage ofthe separation that multiple databases provide. Using multiple databases can alsohelp with availability—the team has never had two databases become unavailableat the same time. Multiple databases also offer a small degree of customizationacross tenants.

In contrast to having one database per tenant, log andconfiguration data are shared per instance.

SXP Monitor. The SXPMonitor is a small application that the team built. The SXP Monitor runs in thesame data center as the Web service, so there is no network in the way. The SXPMonitor runs on a single Web role that runs a single instance.

The SXP Monitor:

• Pings the Web service every 15 seconds to determine whether the service is up. Because the SXP Monitor is in the same data center as the Web service, the service should be available 100 percent of the time. If the SXP Monitor indicates any downtime, the team knows that a problem exists in the data center.
• Trims the Windows Azure Diagnostics storage tables. Windows Azure sends a lot of diagnostics information, but does not clean up that information when it is no longer needed. This would cause the service to slow down if it were querying against many gigabytes of data. Querying the Windows Azure tables is not like querying Microsoft SQL Server® tables because there are no secondary indexes with Windows Azure tables. The SXP Monitor trims the data and keeps just 30 days at all times. The Windows Azure System Center Management Pack will have the same data-trimming functions built in, so the SXP team will retire the data-trimming functions of the SXP Monitor when it migrates to the management pack.
• Provides quick access to the Windows Azure Diagnostics storage tables. The SXP Monitor pulls the data back and sends it as a Microsoft Excel® tab-delimited file. This is a quick way to pull back all of the data without having to page through 1,000 rows at a time, which can take a fair amount of time through remote access.
• Pulls metadata for videos from the MSN Video Web Services. After a specified amount of time, the SXP Monitor pulls new data and caches it into the SXP asset tables.

Windows Azure Storage. The service uses Windows AzureStorage just for diagnostics and log information.

SCOMConnector .The SCOM Connector providesalerting and notification via Microsoft System Center Operations Manager. Theservice currently uses custom code to integrate the SCOM Connector, but the SXPteam is also running the release candidate version of the Windows Azure SystemCenter Management Pack in side-by-side deployment and plans to migrate to the managementpack as soon as it is available. The service gets about 200,000 log entries perday.

Keynote. In addition to the monitoring done through theSXP Monitor, the team monitors through the third-party Keynote product. Keynotepings the Web service from 23 different locales around the world, providinguptime information from an end-user perspective.

Moderation Tool. The ModerationTool manages comments and filters. The Moderation Tool is authenticated by ActiveDirectory® Federation Services (AD FS), which allows extending ActiveDirectory Domain Services (AD DS) authentication into the cloud.

Results

The servicewent live in April 2010. After 120 days of operation, the SXP team comparedresults with the previous third-party solution for the same calendar quarter. Table1 summarizes the before and after statistics.

Table 1. Comparison of third-party solution to SXPsolution over a 120-day period

Availability. Thetable shows that migrating from the third-party product to SXP and WindowsAzure dramatically increased service availability. Availability is measured atthe transaction level. On most days, the service is available 100 percent ofthe time. In the month of July 2010, the service was available 99.999 percentof the time. In fact, Windows Azure running in the South Central data centerhas a similar availability profile to the Microsoft.com data center in EasternWashington. This means that for a fraction of the cost, developers cancomfortably deploy a Windows Azure application and get about the sameavailability worldwide as the Microsoft.com data center. The SXP team expectsthat the availability gains that Windows Azure makes possible will reducedowntime by more than 48 hours over a one-year period.

IT Support Costs. WindowsAzure makes possible the idea of "utility computing." With utility computing, businessescan take advantage of toll-based hardware. This is in contrast to on-premises(purchased) hardware or hosted (leased) hardware. For the SXP service, utilitycomputing results in monthly savings of almost $14,000 compared to the previoussolution. For the month of July 2010, the service delivered 2.4 milliontransactions at a cost of $0.0000965 per transaction, amounting to a total costof $1,050 for the entire month (standard Windows Azure pricing). It isimportant to keep in mind, however, that the SXP service is running at only 5percent utilization. For the $1,050 that the team pays per month for theproduction Windows Azure data center, SXP could support 10 times the currentload.

Planned Downtime.With Windows Azure, service releases are literally push-button activities withzero planned downtime. The SXP team uses the Virtual IP (VIP) Swap feature onthe Windows Azure Portal to promote its staging environment to a productionenvironment. The team has upgraded the service four times by using this featureand has not missed a single transaction. Having such smooth upgrades savesmoney because the team does not have to duplicate its entire environment.

Hardware Provisioning Time.By using Windows Azure, MSIT has reduced the time it takes to order, set up,and repurpose hardware from weeks to minutes. With the new solution, provisioningthe servers takes less than 30 minutes because there is no need to get budgetapproval, order hardware, and rack, stack, and configure the servers.

Key Performance Indicators

The SXP team wanted to be able to determine the value ofthe SXP service on the Video Showcase site. The team wanted to know how manycustomers it was reaching, the engagement level, and the satisfaction level. Table2 shows the business key performance indicators (KPIs) for the period fromproduct launch through May 2010.

Table 2. KPIs from product launch through May 2010

The table shows that number of video views is not large, butthe time spent on each video is significant, because customers are beingengaged for that amount of time. The SXP team measures NSAT by doing surveysafter the fact. The SXP platform enables the team to pull all of this BI dataout in real time and examine the data in Excel. With the previous solution, theteam did not have access to all of this data. This whole set of BI data can bereplicated as the SXP team migrates the service to other sites.

Other Benefits of Developing for Windows Azure

The SXP team also noted the following additional advantagesprovided by Windows Azure.

Robust and Familiar DevelopmentTools

Windows Azure supports open standards and makes use offamiliar tools like Visual Studio and the System Center products. This enabledthe SXP team to quickly design, develop, and deploy a highly interoperable RESTservice that has the performance and on-demand scale that Microsoft.comrequires.

Although there are some important differences to keep inmind when designing, developing, and deploying with Windows Azure (particularlyif the project requires porting a large code base), to a developer, Windows Azureis basically just Internet Information Services (IIS) plus SQL Server. BecauseWindows Azure is so prescriptive, many of the architectural decisions havealready been made. This may not be appropriate for every software solution, butit worked very well for the SXP team.

Consistent Environment

Because Windows Azure packages and deploys the entiresolution in a consistent environment, it prevents time-consuming bugsintroduced by configuration errors and differences.As the team moved from development to testing, to pre-production, andthen to production, and as it brought in new personnel, it did not experiencesome of the normal configuration issues associated with Web development.

For previous projects, the testing team spent a lot oftime resolving configuration-related bugs. With the SXP project, everydeployment that passed the smoke test worked. There is a trade-off for thisconsistency, because developers cannot just update the Web.config file whenre-deploying software. For the SXP team, this tradeoff was worthwhile, but itis an important consideration to keep in mind.

Performance and Scalability

The solution delivers virtually unlimited scalability andsignificantly increased availability at a lower cost when compared to theon-premises solution. The SXP team caches the configuration data, but foreverything else, the team goes back to the database. As the load increases, theteam sees great response times. Even when the service experiences three timesthe normal traffic load, the average response time is still well within theteam’s service level agreements (SLAs), and the team has not seen any hung requests.

SXP team members reside in Austin, Redmond, and Hyderabad,and the data center is in the United States. Performance is excellent in Austinand Redmond and is good in Hyderabad. In future releases, the team will takeadvantage of the Windows Azure data centers in Asia, which will improveperformance there.

Creation of Unique Environments

The SXP team found that it is very fast, easy, and inexpensiveto create unique environments (development, test, integration, pre-production) byusing Windows Azure. When the team is finished with an environment, it can let itgo. When the team wants the environment back again, it can do so very quickly.This reduces the cycle time for ramping up and ramping down.

The SXP team also found that Windows Azure makes it easyto create multiple proof-of-concept environments that greatly improve userfeedback. The team created several demos for business partners. The teamreceived much better feedback from the demos than from the functional specifications.

Global Development

For teams that are spread throughout the globe,traditional solutions require remote access from one location or another.Windows Azure lends itself to global development. A team can deploy anenvironment in its own area. For the SXP project, the development team resides inthe United States and India. The testing team resides in India.

Deployment Automation and Testing

Windows Azure provides an application programminginterface (API) and scripts that fully automate deployment, which reduces humanerror during the deployment process. Due to the standardization on WindowsAzure, the SXP team was able to test its production deployment processes andscripts throughout the software development life cycle. This greatly reducedthe last-minute issues often encountered in production deployment.

Lessons Learned

Writing code for Windows Azure is very familiar fordevelopers accustomed to working with Visual Studio and Microsoft .NET, butthere are also some important differences to keep in mind. The SXP team notedthe following lessons learned:

• Pick the right application. The primary key to success in developing for Windows Azure is to pick the right application. Windows Azure is great for building a Web application or a compute-intensive application, but it is not yet a general-purpose application development platform. The SXP team started with a lower-risk customer-facing project to validate that everything worked as planned.
• Prepare for the impact on operations. Operations is the biggest change when developing for Windows Azure. It is critical to understand the operations impact, get the operations team on board early, and design for operations. Because the SXP team knew that it faced an unknown operations environment, the team heavily instrumented its code so that it would know exactly how many transactions succeeded or failed. The team took advantage of the out-of-the-box Windows Azure Diagnostics to do the bulk of the work but also wrote some small custom tools.
• Prepare early for security and integration. Security and integration are very important considerations. AD FS is a great security solution for authentication. Integration is challenging if there is data inside and outside the firewall. For projects that require integration, it is important to make sure that those problems can be solved before development starts.
• Build in SQL Azure retries. SQL Azure moves databases to balance load. When a database is moved, the connection pool becomes invalid. If the service does not retry the SQL connection, the connect request fails, causing errors. So it is critical to build in SQL Azure retries. For examples of code that retries connections, see the blog entries at http://blogs.msdn.com/b/bartr/.
• Conduct performance testing. Running performance and stress tests with Visual Studio and Windows Azure can be challenging. The problem is the wide area network (WAN) link between the client and the server. The results can become skewed, and the network can quickly become a bottleneck. The potential to accumulate bandwidth costs also exists. The SXP team solved this problem by creating a simple application that it deployed in Windows Azure in the same data center, in order to test heavily on the same network. This testing provided feedback on real performance data.

The cloud and Windows Azure are evolving quickly. Newscripts and tools are available for developers every day. To stay abreast ofchanges and find more information, visit the Windows Azure Portal at http://www.microsoft.com/windowsazure/and the Windows Azure Community site at http://www.microsoft.com/windowsazure/community/.

Conclusion

The SXP team at Microsoft.com created a multi-tenant WindowsAzure-based Web service that enables social media capabilities acrossMicrosoft.com. The Video Showcase site at Microsoft.com is the first tenant forthe SXP service. Customers can use the SXP service to manage comments andratings and to filter out profanity and spam. Customers can also use theservice as an RSS feed aggregation, grooming, and publication service. The SXPteam used familiar development tools to quickly create a solution based onWindows Azure that has extremely high availability, scalability, andperformance. The new solution also offers significant cost savings for MSIT.

For More Information

For more information about Microsoft products orservices, call the Microsoft Sales Information Center at (800) 426-9400. InCanada, call the Microsoft Canada Order Centre at (800) 933-4750. Outside the50 United States and Canada, please contact your local Microsoft subsidiary. Toaccess information via the World Wide Web, go to:

http://www.microsoft.com

http://www.microsoft.com/technet/itshowcase

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