COA OpenStack Heat & Orchestration 3

Question 1

What is the purpose of the 'OS::Heat::AutoScalingGroup' resource?

Accepted Answer

To create a group of identical resources that can scale in or out

Answer

OS::Heat::AutoScalingGroup manages a collection of identical resources (typically servers) and works with scaling policies to add or remove members dynamically.

Question 2

What does 'stack rollback' do in OpenStack Heat?

Accepted Answer

Automatically deletes a stack if its creation fails, restoring the prior state

Answer

When rollback is enabled and a stack creation fails, Heat automatically deletes the partially created stack to avoid leaving orphaned resources.

Question 3

Which command updates an existing Heat stack with a modified template?

Accepted Answer

openstack stack update

Answer

The 'openstack stack update' command applies changes from an updated template or environment to an existing stack, creating, modifying, or deleting resources as needed.

Question 4

What is the 'OS::Heat::WaitCondition' resource used for in Heat templates?

Accepted Answer

To block stack completion until an application inside an instance signals readiness

Answer

OS::Heat::WaitCondition allows Heat to pause and wait for a signal (via a callback URL) from an instance, typically used to confirm that application bootstrapping has completed.

Question 5

Which HOT intrinsic function is used to substitute strings within a template, such as inserting a parameter value into a script?

Accepted Answer

str_replace

Answer

The 'str_replace' function performs string substitution in a template, allowing variables to be injected into user-data scripts or other string values.

(COA) Certified OpenStack Administrator Exam Practice Test

(COA) Certified OpenStack Administrator Exam Practice Test

COA OpenStack Heat & Orchestration 3