Last week, we released a new integration pack for Enterprise Library, specifically targeting Windows Azure.
Most of Enterprise Library just works on Windows Azure so the focus for this integration pack was to add support for additional azure specific scenarios by providing two additional blocks:
· Autoscaling application block (codename WASABI)
· Transient Fault Handling Application Block (codename TOPAZ)
Tailspin Surveys reference implementation
To demonstrate the Windows Azure Integration Pack in a real world like application, we extended an existing reference implementation called Tailspin Surveys to now use Enteprise Library.
Tailspin Surveys is a multi-tenant cloud application that allows tenants to create surveys and analyze survey results. To accommodate fluctuations in load, that’s inherit to such applications, the tailspin surveys application uses the Enterprise Library Autoscaling Application Block to adjust the number of instances to accommodate the load.
Tailspin IT Operators can use the management application to monitor the Tailspin Surveys application and adjust the autoscaling rules.
Wasabi can gather a lot of information about the target environment, such as performance counter values, log messages etc. By turning this information into a graphical display, you can easily see how the load progressed over time and how the number of instances has been adjusted to accommodate these fluctuations.
For example, you can see the number of instances as it changes over time. You can also see when the number of instances was adjusted.
When you click on a scaling event, you can see all the log messages associated with that scaling event. For example, which rules were considered and which rule finally caused the scaling event.
You can also see the values for all the metrics that are gathered. For example, if you decide to monitor the CPU levels, memory pressure and queue lengths, you can see the values for these metrics as they change over time. This allows you to gain insight into how the load of your application progresses over time.
Running the Tailspin reference application.
The Autoscaling block doesn’t work against the development fabric. You can’t autoscale your development environment. So the most realistic way of exploring the Tailspin reference application is to deploy the application to Azure and actually run it there. There is an extensive installation document in the developer guide: http://go.microsoft.com/fwlink/?LinkID=234660
However, if you don’t wish to run it in the cloud, you can also run it in simulated mode. In simulated mode, the autoscaling application block is hosted in memory in the management web application and all the data that the autoscaling application block uses is also stored in memory. The interactions with the Windows Azure Management API are simulated.
Simulated mode allows you to play with the management application, without having to deploy it. You can edit rules, simulate load and then see the results reflected in the graphs.