by Pavlo Revenkov
Customers increasingly want to move their existing solutions into the cloud, and the Windows Azure platform is becoming more and more popular in the field of cloud calculations.
More often than not, SQL Server Reporting Services (SSRS) are part of an application that needs to be migrated into the cloud. SQL Reporting serves as an alternative for the Windows Azure platform.
SQL Reporting is a Windows Azure service for building reports in SQL Azure; it is an equivalent to standard (non-cloud) SQL Server Reporting Services. At first glance, both services appear to provide the same support for developing reports, while SQL Reporting is much cheaper than the common SSRS. Let's see if this is true.
Both solutions can be used for creating multi-tenant scenarios where a server is used by multiple users. Likewise, both solutions can be used in integration with a database running both a common SQL Server and SQL Azure.
As an example, let's take several abstract customers whose web services are located in the Windows Azure cloud and handle a certain number of clients. See the costs of both solutions in the table below.
* - SQL Reporting allows you to generate 30 reports per calculation hour at the price of $0.16.
** - The SQL Server Standard Edition price is used.
At first sight, it appears that SQL Reporting is substantially cheaper than the standard SQL Server that runs on a virtual machine. However, let's suppose that the "Small" customer doesn't have one client that generates 31 reports per hour, but, for example, five clients. How will the price change?
You can see that in the second case, the price for the SQL Reporting service will be higher than the cost of a single virtual machine with an SQL Server, even for the "Small" customer. The price grows proportionally to increases in the number of clients for each customer. Besides, you should also remember that if you generate 31 reports in an hour, it means that the SQL Reporting price will amount to $0.16 (30 out of 30 reports) + $0.16 (1 out of 30 reports) = $0.32. As for a standard SQL Server, you pay for the virtual machine runtime only.
On top of that, the cost of the virtual machine equates to the cost of all its capacities. So you can use the virtual machine not only for generating reports, but also for deploying the database and other things.
Perhaps you think that SQL Reporting involves a much higher SLA than a virtual machine. In this case, that is not necessarily true. According to the Windows Azure Service Level Agreements, the SLA for SQL Reporting amounts to 99.9%.
Yes, a common virtual machine has the same SLA, however, you can configure 2 virtual machines and combine them into an availability set. Thus, you will get an SLA equal to 99.95%.
Support of multi-tenant scenarios
Nine times out of ten, the customer will ask for a single service to build reports for different clients. It is convenient because each report dataset can have different data sources. For example, you can use the same report dataset with different databases and consequently execute a multi-tenant scenario.
Below you can see a brief comparison of SQL Reporting and SSRS in compliance with these requirements.
You can see that both technologies are designed for multi-tenant scenarios. The only difference is that SQL Server can also use Windows authentication to connect to a database. Other distinctions were mentioned above.