Database cloning is a key aspect of the SSRS scale out architecture, with database clones providing each container a complete set of databases. Two or more VMs operated behind a load balancer delivers a highly available and scalable reporting service. This article focuses on Windows SQL Server containers and Windows Virtual Hard Drive (VHD) based cloning, but the same architecture can support SQL Server Linux containers or conventional instances (Windows or Linux). Redgate SQL Clone, for example would support SQL Server instances. Other options include the use of storage arrays instead of Windows VHD based clones. The trade-offs between SQL containers and instances, and between VHDs and storage arrays are covered in separate sections below.
The combination of SSRS containers with database cloning is appealing for simplicity and operational savings. SSRS containers are also drawing interest as part of public cloud strategies, as SSRS containers can be integrated with AWS RDS or SQL Azure databases to provide a horizontally scalable reporting solution.
This is a bit more complex than Reporting Services scale-out with Enterprise Edition, but if you’re on Standard Edition and can’t use scale-out, it’s an interesting alternative.