Dell Doubles Application Speeds, Processes Transactions 9X Faster with In-Memory OLTP

OverviewCustomer: DellCustomer Website: Dell.comCustomer Size: 108,800 employeesCountry or Region: United StatesIndustry: Manufacturing—High tech and electronics manufacturing

Customer ProfileBased in Round Rock, Texas, Dell is a Fortune 100 company that manufactures and globally sells end-user computing, server, storage, networking, and software products and IT services. In 2013, it reported US$57 billion in revenue.

Business SituationDell is always looking to increase the performance of its website, so that its customers can enjoy fast and reliable online shopping experiences around the clock, every day of the year.

SolutionThe company is upgrading many mission-critical databases that support Dell.com to Microsoft SQL Server 2014 to take advantage of In-Memory OLTP.

Benefits Speeds database performance by up to

nine times and boosts security Doubles application throughput Saves money and reduces time spent

on database issues by 77 percent Facilitates 99.99 percent availability

“The performance increase we realize with In-Memory OLTP in SQL Server 2014 is astounding! After just a few hours of work, groups sped database performance by as much as nine times."

Scott Hilleque, Design Architect, Dell

Dell wanted to boost its website performance so that each day, its 10,000 concurrent shoppers enjoyed faster response times. The company also needed to increase its ability to support up to 1 million concurrent shoppers during the holidays. To achieve these goals, Dell is migrating mission-critical databases to Microsoft SQL Server 2014 and taking advantage of In-Memory OLTP to store some tables in memory. By doing so, Dell has sped the performance of databases by up to nine times, which has doubled the throughput capabilities of some web applications and will cut operational costs. In addition, the company can maintain 99.99 percent availability on Dell.com by using SQL Server AlwaysOn; reduce the time spent on database issues and improve security; and transform what’s possible for IT database architects, which is generating a lot of excitement.

SituationAs a global IT leader, Dell manufactures some of the world’s most innovative hardware and software solutions. It also manages one of the most successful e-commerce sites. In 2013, the company facilitated billions in online sales. On a typical day, 10,000 people are browsing Dell.com at the same time. During peak online shopping periods, the number of concurrent shoppers can increase 100 times, to as many as one million people.

Providing customers with the best possible online experience is especially critical to Dell because it does not operate any brick and mortar stores. “Dell.com is really the heart of our company,” says Reinaldo Kibel, Database Strategist at Dell. “Everything is good when the site is up and performing quickly.”

To help facilitate fast, frustration-free shopping despite traffic spikes, Dell has distributed the website’s online transaction processing (OLTP) load between 2,000 virtual machines, which include 27 mission-critical databases that run on Microsoft SQL Server 2012 Enterprise software and the Windows Server 2012 operating system. These databases, along with hundreds of web applications, are supported by Dell PowerEdge servers, Dell Compellent storage, and Dell Networking switches.

Some databases are several terabytes in size and service primarily “read-only” requests for information such as product pages. Other databases are only gigabytes in size, yet contain information used and modified by hundreds of web applications in supporting active browsing sessions. For example, most web applications use a database known as Session. It records the state of the pages each user visits on Dell.com and the information that the user typed (in fields).

Another shared database, known as Context Store, collects and stores profile information for each user—including

country, language, and products purchased. As long as a person is navigating Dell.com, hundreds of applications may potentially write and read from the Context Store because it provides the information that makes it possible to create a customized experience for each customer. “If I know the products you’ve purchased in the past, then if you go to the Support site, it could automatically display the drivers or BIOS updates that you may need for your specific products,” says Scott Hilleque, Design Architect at Dell.

To protect the integrity of shared databases such as Session and Context Store, SQL Server 2012 uses the traditional database file lock model. Although locks prevent multiple processes from changing the same information in a database row, they also slow performance as transaction volumes increase, because processes ultimately encounter locks and have to wait before they can complete a request.

Because the traffic on Dell.com continues to increase each year, especially on peak shopping days during the holidays, Dell actively evaluates emerging technologies to boost performance. This includes looking at solutions that can accelerate OLTP while maintaining transaction atomicity, consistency, isolation, and durability (ACID), which are industry-standard properties for measuring transaction reliability. Engineers also review solutions that can help overcome data-processing challenges (such as table or row locks).

More recently, the company decided to change its approach to database challenges by taking greater advantage of the increased performance capabilities and lower prices of memory in next-generation hardware. Kibel explains, “We were seeking a solution that could run databases in memory, rather than on disk. Our newer Dell PowerEdge servers support terabytes of RAM and some of our databases with the highest transaction loads are just gigabytes in size.”

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“Although the other databases can do a lot of things, they just don’t provide the built-in recovery options that SQL Server 2014 does with In-Memory OLTP and AlwaysOn, which an e-commerce retailer on our scale needs to avoid downtime.”

Scott Hilleque, Design Architect, Dell

SolutionDevelopers evaluated numerous third-party and open-source in-memory tools and databases including RavenDB, MongoDB, and CouchDB. When Dell learned about SQL Server 2014 and its in-memory capabilities, the company immediately signed up to be an early adopter. Not only are memory-optimized tables in SQL Server 2014 lock-free—making it possible for numerous applications to simultaneously access and write to the same database rows—but also the solution is based on the technologies that IT staff already know how to use. Hilleque says, “Although the other databases can do a lot of things, they just don’t provide the built-in recovery options that SQL Server 2014 does with In-Memory OLTP and AlwaysOn, which an e-commerce retailer on our scale needs to avoid downtime.”

For its initial deployment, developers migrated the Context Store and Session databases from SQL Server 2012 to SQL Server 2014 Enterprise. Database administrators then used Microsoft Visual Studio 2013 Ultimate development system and T-SQL Statements to create memory-optimized tables that were ready for use. Hilleque explains, “After SQL Server 2014 was installed on a server, it took a database administrator just a few hours to create a new memory-optimized table including a new database connection string and some stored procedures that mimic the procedures we used for our SQL Server 2012 databases. To start using In-Memory OLTP, I simply changed the connection string in an application to the new one that the developer sent me, and I was ready to load objects into the memory-optimized table. It was just fantastic.”

Supporting the two SQL Server 2014 databases are two Dell PowerEdge M620 blade servers, which reside in a Dell M1000e chassis. SQL Server AlwaysOn ensures that the servers are configured as replicas of each another. The servers are connected to each other and to the

network via 10 Gigabit Ethernet (GbE) Dell Networking switches.

Initially, engineers set up the database tables to be fully durable, meaning that the table replicas are synchronous copies. However, developers can also configure the tables to use delayed durability, which means that changes made to a table’s replica are delayed slightly to minimize any impact on performance.

During the course of testing SQL Server 2014, Dell collaborated with Microsoft developers to help fine-tune its solution. “We worked with the Microsoft SQL Server team to pare down the log files and checkpoint data files that track changes made to memory-optimized tables, and now we have sleek-sized log and checkpoint data files that don’t take up too much space,” says Kibel. “The level of interaction we’ve had with the Microsoft team, especially during the SQL Server 2014 early adoption program, has been phenomenal.”

In April 2014, Dell Support will be the first group in the company to use SQL Server 2014 and In-Memory OLTP in production. Meanwhile, engineers are migrating other databases to SQL Server 2014, including systems supporting Dell.com and corporate applications used by employees. Because SQL Server 2014 databases can include tables on disk and in memory, developers are also using the Analysis, Migrate and Report (AMR) tool in SQL Server 2014 Management Studio to pinpoint which tables and procedures are ideal candidates for In-Memory OLTP.

BenefitsBy upgrading databases to SQL Server 2014 and taking advantage of In-Memory OLTP, Dell dramatically increases database performance, application throughput, cost savings, and staff’s enthusiasm—while also maintaining high availability and minimizing time spent on database issues.

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“In-Memory OLTP in SQL Server 2014 really signifies a new mindset in database development because with it, we no longer have to deal with the performance hits caused by database locks—and this is just one of the amazing benefits of this solution.”

Reinaldo Kibel, Database Strategist, Dell

Speeds Databases by up to Nine TimesBy gaining the option to store tables in memory, Dell is achieving unprecedented OLTP speeds. “The performance increase we realize with In-Memory OLTP in SQL Server 2014 is astounding!” says Hilleque. “After just a few hours of work, groups sped database performance by as much as nine times. And all aspects of our In-Memory OLTP experience has been seamless for our staff because it is so easy to adopt, and its implementation produces zero friction for architects, developers, database administrators, and operations staff.”

Elaborating on this point, Kibel says, “In-Memory OLTP in SQL Server 2014 really signifies a new mindset in database development because with it, we no longer have to deal with the performance hits caused by database locks—and this is just one of the amazing benefits of this solution. No more dealing with deadlocks, latches, and locking while still maintaining the ACID properties of the data.”

Doubles Application Performance and Saves MoneyAlthough Dell is in the very early stages of adopting SQL Server 2014, IT workers are excited by the impact of In-Memory OLTP. The more the IT team can speed database performance, the faster web applications can get the information that they need to deliver a responsive and customized browsing experience for customers. And when one system can handle a larger volume of requests—and in less time—fewer systems are needed. “Our first adopter has more than doubled the end-to-end throughput of its web applications that use SQL Server 2014 rather than SQL Server 2012,” says Hilleque. “As a result, they will need fewer virtual machines.”

Protects 99.99 Percent Availability and Provides FlexibilityWith SQL Server 2014, Dell can take advantage of memory-optimized tables without sacrificing high availability. “The

fact that we get great features like SQL Server AlwaysOn and In-Memory OLTP in the same database is significant for us because we can further improve database performance and still maintain 99.99 percent availability,” says Thirumala Kommineni, Database Architect at Dell.

In addition, IT personnel can configure how table data is replicated by setting up memory-optimized tables to use full durability or delayed durability. Although IT personnel are currently using full durability, they are testing delayed durability for some databases such as Session. “The performance payoff we’d realize with delayed durability might be worth the risk because each user would see pages load up to one second faster,” says Hilleque. “And because we’re dealing with tens of thousands of simultaneous users, any data lost during a rare unplanned failover might cause just a few people to lose their sessions, which would bring them back to the home page.”

Reduces Time Spent on Database Issues by 77 Percent and Boosts SecurityWhile Dell continues to run its mission-critical databases on SQL Server, some other systems within the company run on other vendors’ products, giving IT personnel direct insight into the differences between platforms. Kibel says, “When we compare the number of incident cases for all of our databases, the ratio of tickets filed for our other platforms compared with SQL Server are 1,000 to 1, with SQL Server being the 1. As a result, we spend 77 percent less time troubleshooting issues on SQL Server than we do on our other databases.”

Dell also enjoys better security with the Microsoft platform. “Over the past several years, our other database vendors have released a security patch every quarter,” says Kibel. “The last security patch for SQL Server was two and a half years ago. SQL Server is a much more secure environment.”

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“”“The fact that we get great features like SQL Server AlwaysOn and In-Memory OLTP in the same database is significant for us because we can further improve database performance and still maintain 99.99 percent availability.”

Thirumala Kommineni, Database Architect, Dell

Generates Excitement and Innovation The 2,000 virtual machines that support Dell.com are maintained by numerous IT groups that brainstorm and collaborate to continually improve customers’ online shopping and support experiences. The adoption of SQL Server 2014 has triggered a lot of excitement. “We have a weekly architects call, and In-Memory OLTP in SQL Server 2014 has dominated discussions for the last six months,” says Hilleque. “People are really impressed by the tool and want to know how they can use it to transform performance, improve service, and save money.”

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Software and Services Microsoft Server Product Portfolio− Windows Server 2012 Enterprise− Microsoft SQL Server 2014 Enterprise

Microsoft Visual Studio− Microsoft Visual Studio 2013

Ultimate Technologies− Microsoft SQL Server 2014

Management Studio

Hardware Dell PowerEdge M620 blade servers Dell PowerEdge M1000e chassis Dell Networking switches Dell Compellent Storage SAN

Unlock insights on any dataMicrosoft business intelligence (BI) solutions simplify access to virtually any type of data, whether it resides in the business or the cloud. Powered by Microsoft SQL Server, and built into familiar programs such as Microsoft Excel, BI tools speed insight into data from multiple sources, including business applications, blogs, and sensors.

For more information about unlocking insights on any data, go to:www.microsoft.com/en-us/server-cloud/cloud-os/data-insights.aspx

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