Case Study Sunweb Group

“Coeo specialise in Microsoft data services – their expertise and depth of knowledge on the subject means that the total environment is tuned to the optimum.”

Bas Bruijninckx, IT Manager – Sunweb Group

Project Overview

Coeo has helped Sunweb Group, one of Europe's leading tour operators, to improve performance of its online reservation system by implementing the latest SQL Server features.


Sunweb Group, one of Europe’s leading travel groups, sells holidays to destinations throughout Europe. One of the first operators to implement an online reservation system in 2002, Sunweb’s competitive advantage was eroded as other companies also started selling through websites. Europe’s highly competitive marketplace made it easy for newcomers to penetrate the market and, as competition increased, Sunweb looked for ways to boost performance and improve service to customers.

With a high volume of sales critical to their success, Sunweb needed to take full advantage of the peak booking seasons which occur twice annually for summer holidays and winter sports vacations. For those few weeks, sales jump from approximately €400k to €3.8 million per day. Any delay can be costly. As Bas Bruijninckx, IT Manager at Sunweb Group says, “If customers don’t get a response in a couple of seconds they will book elsewhere.”

The Challenge

Achieving and maintaining optimum performance during their peak seasons was one challenge. In addition, the company was expanding operations in eight European countries. With plans to double in size within 2 years, the company needed a more scalable infrastructure. Other areas of improvement had been identified. For example, marketing teams would run reports on the same servers used for online transaction processing (OTLP), resulting in transactions often locking when customers ran searches.

In the past, Sunweb Group added servers to support peak sale periods. Instead the company wanted to improve performance and support growth by optimising its data management solution and taking advantage of the elastic scale of Azure.


Coeo had already helped Sunweb Group upgrade SQL Server several times as new features were released to improve business performance and also remotely manages the Sunweb Group SQL Server infrastructure from London, so it was the obvious choice to help achieve this. As Bruijninckx comments: “We were looking for a very knowledgeable partner and Coeo really knows how to tune the total environment to the optimum.”

Coeo helped Sunweb design and test a new solution to meet the business needs. The solution was put into production four months later. The new infrastructure separates the servers that are used for customer searches and those that process reservations allowing the company to scale significantly further than a single server solution would allow. Changes are published to the front-end search servers through transactional replication. The company manages approximately 6.5 terabytes of data.

To reduce search times, the latest in-memory SQL Server technology was selected along with the hyperscale capabilities of Azure.

The optimised data management platform includes the Microsoft SQL Server AlwaysOn feature which is typically used as part of a disaster-recovery and high-availability solution. However, Sunweb Group uses the AlwaysOn Availability Groups capability to improve performance of its entire infrastructure. By offloading a workload to secondary servers, which the marketing team uses for reports, performance bottlenecks on the frontline OLTP servers are reduced. In addition, automatic failover with AlwaysOn Failover Clustering helps ensure availability and reliability.


Improved performance and scalability have meant Sunweb can take full advantage of sales periods and boost support for its rapidly growing business.

Sunweb Group can now look ahead with confidence when it comes to handling its busiest booking seasons. It expects to serve a higher volume of customers and improve margins as a result. When sales skyrocket, Sunweb can take full advantage of these daily revenue spikes. Bruijninckx says “With the SQL Server AlwaysOn feature, we can offload less critical workloads and make more resources available to our customers during peak reservation periods.”

Sunweb has been impressed with the level of commitment, support and service received from Coeo. “The lengths they go to to deliver are tremendous”, comments Bruijninckx. With Coeo consultants working on site and DBAs working remotely around the clock, a lot of time is spent with Sunweb’s developers to really take advantage of the capabilities and features of SQL and get the best performance out of the system already in the development process. “Rather than developing things and waiting for issues to arise in production, Coeo’s team already start to be involved in the development process. Together we call this process ‘performance engineering’,” says Bruijninckx.

With greater stability and scalability across the whole platform, Bruijninckx says “We rely less on hardware redundancy and more on the high level of availability that we get with SQL Server AlwaysOn Availability Groups.” And Sunweb believes that the platform is the best choice for supporting its ambitious growth targets which include expanding its business model in Europe doubling in size over the next two years. “The Microsoft platform with SQL Server supports us by enabling us to scale up and out,” says Bruijninckx.

Since completing the project there have been fewer issues around the performance of replicated data and the company now looks forward to taking advantage of more capabilities in SQL Server.

“Microsoft technology supports us so that we can do the business we need to do. It provides us with the flexibility, performance and functionality required to achieve our goals. But Coeo has made the technology work for us,” says Bruijninckx.

“They’re steering the project with Microsoft and have taken care of a lot of the heavy lifting in terms of strategy, design, installations, migrations, and updates of the database which has greatly reduced the amount of effort for us.”