Jenkins Jenkins Build Triggers and Scheduling

Question 1

Which Jenkins trigger automatically starts a build when a source code change is detected in the SCM repository?

Accepted Answer

Poll SCM

Answer

Poll SCM periodically checks the SCM repository for changes and triggers a build only when changes are detected.

Question 2

What cron syntax would you use in Jenkins to run a build every day at midnight?

Accepted Answer

0 0 * * *

Answer

In Jenkins cron syntax, '0 0 * * *' means minute 0, hour 0 (midnight), every day of the month, every month, every day of the week.

Question 3

Which Jenkins trigger is used to start a build via an HTTP request to a specific URL using a token?

Accepted Answer

Trigger builds remotely

Answer

Trigger builds remotely allows external systems to start a Jenkins build by calling a URL with an authentication token.

Question 4

In Jenkins, what does the 'Build after other projects are built' trigger do?

Accepted Answer

Starts a build when specified upstream projects complete

Answer

This trigger creates a dependency relationship so the current job runs automatically after specified upstream jobs finish building.

Question 5

What is the purpose of the 'H' symbol in Jenkins cron scheduling expressions?

Accepted Answer

Hashed scheduling to spread load across time

Answer

The 'H' symbol uses a hash of the job name to select a consistent but distributed time, preventing many jobs from triggering simultaneously.

Jenkins Practice Test