Learn about DaemonSets in Kubernetes and how they ensure specific nodes run a copy of a Pod. Discover their role in maintaining desired state across nodes.
Table of Contents
Question
What is a DaemonSet?
A. It’s a type of workload that ensures a specific set of nodes run a copy of a Pod.
B. It’s a type of workload responsible for maintaining a stable set of replica Pods running in any node.
C. It’s a type of workload that needs to be run periodically on a given schedule.
D. It’s a type of workload that provides guarantees about ordering, uniqueness, and identity of a set of Pods.
Answer
A. It’s a type of workload that ensures a specific set of nodes run a copy of a Pod.
Explanation
A DaemonSet is a type of workload in Kubernetes that ensures a specific set of nodes run a copy of a Pod. It is responsible for guaranteeing that a particular Pod is always running on each node that matches a specified label selector.
When a DaemonSet is created, the Kubernetes control plane schedules a single Pod replica on every node in the cluster that satisfies the DaemonSet’s node selector. If new nodes are added to the cluster that match the selector, the DaemonSet automatically deploys a Pod replica on those nodes as well.
DaemonSets are particularly useful for running system daemons or background processes that need to be present on every node in the cluster. Some common use cases for DaemonSets include:
- Log collectors: Running a log collection agent on each node to gather and forward logs to a centralized logging system.
- Monitoring agents: Deploying monitoring agents on each node to collect metrics and monitor the health of the node and its resources.
- Network plugins: Running network plugin daemons on each node to configure and manage the cluster’s networking.
- Storage daemons: Deploying storage daemons on each node to provide persistent storage capabilities to the cluster.
Unlike other types of workloads, such as Deployments or ReplicaSets, DaemonSets do not maintain a stable set of replica Pods across all nodes. Instead, they ensure that a specific set of nodes always runs a copy of the desired Pod.
In summary, a DaemonSet is a powerful tool in Kubernetes for deploying and managing Pods that need to run on every node in the cluster, providing a reliable and automated way to maintain the desired state of system daemons and background processes across the entire cluster.
Linux Foundation KCNA certification exam assessment practice question and answer (Q&A) dump including multiple choice questions (MCQ) and objective type questions, with detail explanation and reference available free, helpful to pass the Linux Foundation KCNA exam and earn Linux Foundation KCNA certification.