Objective 1.3: Design and implement the Windows Azure role life cycle

Question 1

There are three different types of solutions available in Windows Azure:

Answer 1

Virtual Machines, Web Sites, and Cloud Services

Question 2

There are three types of roles in Windows azure

Answer 2

Web, Worker and Virtual Machines

Question 3

What do the startup tasks allow to do?

Answer 3

With startup tasks, you can register COM components, install a component, or set registry keys, for example.

Question 4

For which roles are startup tasks available?

Answer 4

Startup tasks are available only for Web and Worker roles; VM roles cannot manage startup tasks.

Question 5

What would be a typical startup task?

Answer 5

A typical startup task is a console application or a batch file that
can start one or more Windows PowerShell scripts.

Question 6

What is the procedure that Windows Azure follows to start a role?

Answer 6

1. The instance is marked as Starting. It will no longer receive traffic.
2. Startup tasks are executed according to their taskType attribute:
   A. Simple tasks are executed synchronously.
   B. Background and foreground tasks are started asynchronously. This is in parallel with the tartup task.
3. The role host process is started and the site is created in IIS.
4. The task calls the Microsoft.WindowsAzure.ServiceRuntime.RoleEntryPoint.OnStart
   method.
5. The instance is marked as Ready and traffic is routed to the instance.
6. The task calls the Microsoft.WindowsAzure.ServiceRuntime.RoleEntryPoint.Run method.

Question 7

What occurs if an unhandled error is fired on a startup task?

Answer 7

The task will stop processing and return a non-zero value.

Question 8

AppCmd.exe is an application that helps you work with which objects?

Answer 8

• AppCmd.exe enables the configuration of virtual sites.
• AppCmd.exe supports the administration of general configuration
  sections.
• AppCmd.exe manages the support of applications.

Question 9

Which of the following are valid reasons for overriding the Run method? (Choose all that apply.)

Answer 9

A.
Creating and starting a messaging service that will work in parallel with the Web role to manage queued messages
B.
Creating an always-running service that periodically makes HTTP calls to other websites to determine their availability
C.
Managing error handling for the application
D.
Starting and supporting a logging application for use by the Worker role

Correct answers: A, B, D
A. Correct: Creating and running an application in parallel is what the Run method
was designed to allow.
B. Correct: The polling service is a good example of an activity in which the Run
method enables a process to work independently of the main role.
C. Incorrect: The error handling will be managed in the OnError event and will not
involve the overridden Run method.
D. Correct: Creating and running an application in parallel is what the Run method
was designed to allow.