Azure App Service is a cost effective, reliable and resilient platform for hosting Umbraco. In fact, for sites that need anything beyond the most basic hosting, it's our preferred hosting platform.

One useful feature of App Service is that it can be run in a load balanced configuration, which means that instead of a single computer serving content, you have many computers working together and taking it in turns to serve content. 

Load balancing has a number of benefits: 

• By sharing the load across multiple servers, you increase the reliability of the website. So if a failure should occur on one server the chances are the other servers in the cluster will still be working and Azure will balance the site traffic across the remaining servers reducing the likelihood of  downtime; and
• For large sites, the computing power needed to operate the site is often cheaper when spread across multiple smaller servers than one huge server.

Putting the impact of an outage into perspective, or an e-commerce site turning over £5m in sales per year, an outage caused by faulty hardware which might take a couple of hours to fix, that could equate to £1,500 in lost sales.  

Moving to a load balanced cluster using Azure App Service also introduces the ability to Autoscale - which means giving Azure the capability to add additional servers to the hosting cluster when the site traffic increases.  For sites with peaks and troughs of traffic, for example Vendr E-commerce sites with seasonal peaks around Black Friday and Boxing Day Sales, auto-scaling can detect increased load on the site and add extra servers, and then reduce the number as traffic decreases after.

Having supported a number of high profile sites to migrate to a Azure App Service load balanced cluster, we've built up the knowledge and experience to design hosting infrastructure to meet specific client needs that aligns with Azure Reference Architecture best practice.