Jenkins Administration Flashcards

Which Jenkins feature allows you to back up and restore jobs, credentials, and configuration as a WAR archive?

Answer: Thin Backup Plugin or file-system backup of JENKINS_HOME

The recommended backup approach is to copy `JENKINS_HOME` (or use the ThinBackup plugin) which contains all jobs, config, and credentials.

How can you run a Groovy initialization script automatically when Jenkins starts?

Answer: Place a .groovy file in JENKINS_HOME/init.groovy.d/

Groovy scripts placed in `JENKINS_HOME/init.groovy.d/` are executed automatically in alphabetical order during Jenkins startup.

What is the purpose of the Jenkins `build-discarder` strategy?

Answer: Automatically delete old builds to conserve disk space

The build discarder (log rotation) strategy deletes older builds and artifacts based on count or age to prevent JENKINS_HOME from filling up.

Which system property controls the Jenkins URL used in notifications and links?

Answer: Jenkins URL set in Manage Jenkins > System Configuration

The Jenkins URL is configured under Manage Jenkins > System > Jenkins URL and is stored in `config.xml` as ``, used in email links and webhooks.

What does the `Reload Configuration from Disk` option in Manage Jenkins do?

Answer: Reloads Jenkins config from JENKINS_HOME XML files without restarting

Reload Configuration from Disk re-reads all job and system XML files from disk, applying changes made outside the UI without a full restart.

How do you monitor Jenkins controller memory usage and thread dumps for troubleshooting?

Answer: Access /manage/diagnostics or use the Support Core Plugin

The Support Core Plugin and the `/manage/diagnostics` endpoint provide thread dumps, heap info, and system diagnostics for Jenkins troubleshooting.