SQL Azure Federation Enables Building of Large Scale Database Tiers

Microsoft has been very busy the past few days with delivering a variety of updates and enhancements for Windows Azure, including making available the SQL Azure Q4 2011 Service Release, which, among other features, came with SQL Azure Federation.

With SQL Azure Q4 2011 Service Release, Microsoft put in place new pricing for its customers to take advantage of, enabling them to build large databases without having to pay more for them.

In addition to that, the company brought along SQL Azure Federation, aimed specifically at enabling the development of elastic and scalable database tiers.

The new solution is meant to bring to the database tier a model of scalability that has been so far met on canonical 3-tier applications, which are designed to handle increased user workloads by adding and removing nodes to the front and middle tiers.

Courtesy of Federations, applications should be able leverage the capacity of 10s or 100s of nodes, thus scaling beyond a single SQL Azure database. Administrators will be offered the possibility to expand and shrink the capacity of the database tier without interrupting the workflow.

For example, when it comes to handling the traffic generated by a blog-hosting website, Federations could easily repartition operations on servers, so that there will not be idle servers while others are saturated due to increased traffic on some of the blogs.

A new federation can be easily created through the SQL Azure Management Portal, via the New Federation icon available on the database page.

Details on the federation, including its layout, are available on the Federations Details page. Also there, the SPLIT action will offer the option to scale out the federation for handling larger amounts of traffic as more members join. Detailed info on the SPLIT operation is available as well.

When the application scales, additional SPLIT points are introduced. Administrators are offered the possibility to split a federation into more federation members as the application workload increases, Microsoft explains in a blog post.

Key benefits of Federations would include:

Massive Scale: Federations bring in the sharding pattern in SQL Azure and allow harnessing of massive capacity at the database tier. Combined with the power of SQL Azure, administrators can choose to engage 10s or 100s of nodes within the SQL Azure cluster.

Best Economics: With federations, database tiers become truly elastic. Administrators can repartition applications based on workload to engage or disengage SQL Azure nodes. With federations, no downtime is required for these repartitioning operations.

Simplified Development and Administration of Scale-out Database Systems: Federations come with a robust programming and connectivity model for creating dynamic applications. With native tooling support for managing federations and with online repartitioning operations for orchestrating federation at runtime, federations greatly ease management of databases at scale.

Simplified Multi-tenant Database Tiers: Multi-tenancy provides great efficiencies by increasing the density of tenants per database. However, a static decision on placement of tenants rarely works for the long tail of tenants or for large customers that may hit scale limitations of a single database. With federations applications don’t have to make a static decision about tenant placement. Federations provide repartitioning operations for efficient management of tenant placement and re-placement and can deliver this without any application downtime.