CJE Distributed Builds & Agent Management

Question 1

What is the default TCP port used by Jenkins agents when connecting to the controller via the inbound agent (JNLP) protocol?

Accepted Answer

50000

Answer

Jenkins agents using the JNLP/TCP inbound protocol connect to the Jenkins controller on port 50000 by default, separate from the web UI port 8080.

Question 2

What is the primary purpose of assigning a 'label' to a Jenkins agent?

Accepted Answer

To group agents so that jobs can target nodes with specific capabilities or OS types

Answer

Labels allow jobs to specify which agents they can run on using the 'node' or 'agent' directive, enabling routing to agents with specific capabilities such as 'linux', 'docker', or 'gpu'.

Question 3

Which Jenkins agent connection method should be used when a firewall prevents the controller from initiating a connection to the agent?

Accepted Answer

Launch agent by connecting it to the controller (Inbound/JNLP)

Answer

The inbound/JNLP method allows the agent to initiate the TCP connection to the controller, bypassing firewall rules that block inbound connections from the controller to the agent.

Question 4

What does the '# of executors' setting on a Jenkins node control?

Accepted Answer

The number of concurrent builds that can run simultaneously on that node

Answer

The number of executors defines how many concurrent build processes can run simultaneously on a specific node, directly controlling its parallel build capacity.

Question 5

What is the 'Remote root directory' setting when configuring a Jenkins agent?

Accepted Answer

The directory on the agent machine where Jenkins stores workspaces, caches, and build data

Answer

The remote root directory is the working directory on the agent machine where Jenkins creates per-job workspaces and stores temporary files needed during builds.

CJE - Certified Jenkins Engineer Practice Test

CJE - Certified Jenkins Engineer Practice Test

CJE Distributed Builds & Agent Management