Case Studies: Buienradar

Cloudy Skies Bring Heavy Traffic to Buienradar's Weather Websites

Buienradar is a Dutch website that provides real-time, radar-based weather information for the Netherlands and another site for the rest of Europe. The website, www.buienradar.nl, allows weather watchers to monitor rainfall conditions by entering a location, ranging from the Netherlands to Germany to Scotland, and the website generates a rainfall map of the desired region, as shown at left.

The website is among the most popular in the Netherlands and is the number one site for weather-related information, with users seeking streaming information from their home PCs, smartphones, gas stations, and even hotel kiosks. The website receives approximately 5 million unique visitors per month, with this number spiking to 15 million visitors during times of severe weather. The site receives between 4–5 Gbps of sustained traffic, even during times of relatively mild weather.

The Netherlands are famous for an elaborate system of levees and dams that keep the sea at bay. With the region's low-lying geography, more than 20 percent of the Dutch populace resides on land that is below sea level, so the local fascination with weather reports that Buienradar has been witnessing makes sense.

Buienradar in Search of a More Robust Load Balancer

Buienradar's network is split across a primary and secondary data center. Each data center has a cluster of web servers connected using carrier-grade routers and switches. Network traffic consisting mainly of HTTP is spread across the servers using load balancers. The relatively low performance numbers (i.e. only 5 million concurrent sessions) of the company's legacy load balancers meant that they had to be deployed in Direct Server Return (DSR) mode, as opposed to Routed mode. The DSR mode deployment caused server responses to bypass the load balancer, which, in turn, caused many of the load balancer's advanced features to be disabled. When the legacy load balancers reached end of life, Buienradar sought a more robust replacement.

In considering their distributed network with geographically separate data centers, Buienradar needed a new generation server load balancer capable of providing Global Server Load Balancing (GSLB). The new appliance would also need to offer higher throughput than the legacy load balancers in order to allow Buienradar to install the AX Series in Routed mode, as opposed to DSR mode, as was necessary with the predecessors.

Another criterion that would affect the company's purchasing decision was the impending depletion of IPv4 addresses. As more and more end users migrate to the IPv6 protocol, Buienradar's goal was to be ready to meet the needs of this small but growing number of IPv6 clients.

Buienradar's Logical Network

AX Series: IPv6 Support, GSLB, and DNS Protection

Buienradar chose to install the AX Series Application Delivery Controllers (ADC) for the following reasons:

• IPv6 Support: Buienradar had a strategic initiative to have its sites ready for "World IPv6 Day" on June 8th, 2011. By deploying the A10 Networks AX ADCs, the company is on target to meet this goal. The AXs can utilize Server Load Balancing–Protocol Translation (SLB-PT), acting as an IPv4/IPv6 gateway. This enables IPv6 clients to access content using the organization's existing IPv4-based web servers. The AX also supports native IPv6, allowing an end-to-end IPv6 network.
  
  
• GSLB Support: With two separate data centers, Buienradar needed a load balancer with GSLB support to ensure that client requests are properly routed to the data center closest to the end users. The AX ADC's GSLB feature can direct user requests to the optimal data center, based on response times for ping or DNS requests, or the AX ADC can integrate with geo-location services using any CSV format.
  
  
• DNS Application Firewall: This crucial application layer feature ensures the availability of critical DNS infrastructure by allowing legitimate DNS protocol traffic to pass while denying non-DNS traffic. Optionally, traffic can be quarantined for later inspection. By using the DNS Application Firewall feature, organizations can reduce the load on their backend servers by up to 70 percent.

Success: Blue Skies Ahead for Buienradar's Network

After considering a range of options, Buienradar selected A10 Networks' AX Series 64-bit ADCs. The AX 2500 Series offer 10 Gbps throughput capacity, and 64-bit scalability enables support for tens of millions of concurrent sessions. These higher performance numbers enabled Buienradar to deploy the AXs in Routed mode instead of DSR mode, giving them greater control of the traffic returning to the clients and enabling them to leverage the AX's advanced features on outbound traffic, such as aFleX inspection and content adjustment.

In addition, the AX Series offers enhanced security for web and DNS servers. By leveraging the AX Series' built-in security features, Buienradar was spared the cost and complexity of having to install and manage a separate, dedicated firewall solution.

The AX ADCs offer an affordable solution with maximum throughput for periods of heavy traffic. Since Buienradar deployed its AX appliances, the company's website effortlessly handles the peak traffic loads that occur during periods of severe weather. Sophisticated GSLB support helps direct traffic between the company's two data centers, and the GSLB functionality is included at no additional cost. Lastly, the company has benefited from the AX's IPv6 support and the sites are on track to be ready for "World IPv6 Day" in June, 2011.

About AX Series

A10 Networks' AX Series is the industry's best price/performance advanced traffic manager – helping enterprises and ISPs maximize application availability through a high-performance and scalable web Application Delivery platform. The AX's Advanced Core Operating System (ACOS) architecture has garnered the company numerous awards and is revolutionary by market standards due to its scalable symmetrical multiprocessing (SSMP), shared memory architecture. AX includes an optimized multi-CPU architecture built from the ground up that leaps ahead of the competition in terms of performance, scalability, and reliability. For more information, visit: www.a10networks.com/products/axseries

About A10 Networks

A10 Networks was founded in 2004 with a mission to provide innovative networking and security solutions. A10 Networks makes high-performance products that help organizations accelerate, optimize and secure their applications. A10 Networks is headquartered in Silicon Valley with offices in the United States, United Kingdom, France, the Netherlands, Germany, Brazil, Japan, China, Korea, Taiwan and Hong Kong. For more information, visit: www.a10networks.com

About Buienradar

Buienradar, which translates to "rain radar", is one of the most-visited websites in the Netherlands and is the number one destination for rainfall information in Holland. The website receives up to 15 million unique visitors per month. For more information, please visit: www.buienradar.nl