Windows Azure Caching

Caching provides a distributed, in-memory, application cache service for Windows Azure applications. Instead of relying on slower disk-based storage, applications gain high- speed access and scale to data that is kept in-memory.  Caching is a managed service that is operated by Microsoft and has 99.9% monthly SLA.

There are many practical uses for Caching.  Some common uses include:

Read-only data

Caching can be used to provide applications with quick access to frequently used data. Keeping this data in a cache instead of fetching it from storage or a database, provides the application with increased scalability as well as enhanced performance and usability. 

For instance, data representing a product catalog or a country list, which is read frequently by the application, can be easily loaded to the cache when the application starts, resulting in increased performance and improved overall end-user experience.

User session data

Caching can be used to provide the application with quick access to a specific users’ session data. This type of data is frequently read and updated. Keeping this data in a cache provides a simple way to improve application performance, enables access to the data in scale-out scenarios, and removes unnecessary load from the database.

For example, data of a user’s shopping cart in an online commerce application can be managed in-memory until the purchase is complete and the data is stored to persistent storage or a database.

Application resource data

Just like user session data, shared resource data is updated frequently during an application’s execution, though the data is not related to a specific session, but rather is shared across the application.

For example, data of an airline’s seating inventory requires frequent access across different user sessions to fetch and update as seats are reserved for various flights.

Capabilities and Benefits of Caching

• Easily scale up or scale down by dynamically increasing or decreasing the cache size through configuration.
• Create a cache by choosing the cache size and region, and the service takes care of all the provisioning and management.
• Caching provides the flexibility to cache any type of managed object, including: XML, Binary Data, Rows and CLR Objects.
• Enable acceleration of web applications, through configuration changes only, without having to modify application code, using pre-built ASP.NET providers for session state and page output caching.     
• Secured access and authorization to the cache is achieved by using security tokens from the Access Control service.
• The Caching service has a consistent development model with its Windows Server caching technology counterpart.

Pricing and Metering for Caching

Caching is priced per cache size per month.

Visit MSDN to get in-depth information on Caching.