Database Reference
In-Depth Information
Keep in mind that you can design an application to use both connection methods. You may
determine that your application needs to connect directly when archiving data, while using services to
perform more complex functions.
Note
Most of this chapter provides direct connection diagrams; however, many of the patterns presented would
work just as well using a serviced connection to a Windows Azure service first.
Pricing
Pricing of a hosted environment isn't usually considered a factor when it comes to standard application
design. However, in the case of cloud computing, including Azure, you need to keep in mind that your
application's performance and overall design have a direct impact on your monthly costs.
For example, you incur network and processing fees whenever you deploy and use Azure services.
Although this is true, at the time of this writing the data traffic between a Windows Azure application or
service and a SQL Azure database is free within the same geographic location.
Pricing may affect your short-term application design choices, but you should keep in mind that
Microsoft may change its pricing strategy at any time. As a result, although pricing is an important
consideration especially for projects on limited budget, long-term viability of a design should be more
important than short-term financial gains.
If you're designing an application to live in the Azure world and you depend on this application to
generate revenue, you must ensure that your pricing model covers the resulting operational costs. For
example, your application should be designed from the ground up with billing capabilities in mind if you
intend to charge for its use.
Another factor related to pricing is that your SQL Azure database cost consists of a monthly fee and
a usage fee. The monthly fee is prorated, so if you create a database at 1
PM
and drop it at 2
PM
the same
day, you're charged a fraction of the monthly fee, plus the usage fee. The usage fee is strictly limited to
bandwidth consumption: CPU utilization, I/O consumption, and your database's memory footprint
aren't factors in the usage fee (see Figure 2-3). However, your database connection may be throttled if
your CPU, I/O, and/or memory consumption reaches specific thresholds.
Figure 2-3.
Pricing and resource throttling
