Juniper JN0-213 Practice Test - Questions Answers, Page 2

The kubelet is a component of Kubernetes that runs on all nodes in the cluster and ensures that containers are running in a pod910.It takes a set of PodSpecs that are provided through various mechanisms and ensures that the containers described in those PodSpecs are running and healthy

Containers are lightweight because they don't need the extra load of a hypervisor, but run directly within the host machine's kernel1. This means they start up almost instantly and use less RAM.Images are constructed from layered filesystems and share common files, making disk usage and image downloads much more efficient1. Containers are isolated from each other and the host system.They have their own filesystem and networking, and can be constrained to not allow root access outside the container1.They run on top of a host operating system1.

In Kubernetes, a Pod is the smallest and simplest unit in the Kubernetes object model that you create or deploy23.A Pod represents processes running on your cluster23.A Service in Kubernetes is an abstraction which defines a logical set of Pods and a policy by which to access them23.

An overlay network is a virtual network that is built on top of another network.Nodes in the overlay network are connected by virtual or logical links, each of which corresponds to a path, perhaps through many physical links, in the underlying network45.For example, distributed systems such as peer-to-peer networks and client-server applications often overlay their own network connections over the physical network connections provided by the Internet

The LoadBalancer service type in Kubernetes exposes the service externally using a cloud provider's load balancer67.NodePort and ClusterIP services, to which the external load balancer routes, are automatically created

hefree -hcommand in Linux displays the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel89.Thecat /proc/meminfocommand displays real-time information about the system's memory usage as well as the buffers and shared memory used by the kernel1

Overlay networks are indeed virtual networks.They are logical constructs that stitch together disparate, dispersed network infrastructure, often referred to as underlay1.Underlay networks refer to the physical network infrastructure, while overlay networks implement network virtualization concepts2. Reference from Juniper site:Baeldung on Computer Science,PacketFabric,Cisco,HPE Aruba Networking

A daemonSet in Kubernetes ensures that a replica of a pod is running on all nodes3.A ClusterIP type service can only be accessed within a Kubernetes cluster3. Reference from Juniper site:Kubernetes Documentation

The Docker component that builds, runs, and distributes Docker containers is dockerd. Dockerd is the persistent process that manages containers. Docker uses different binaries for different tasks. For example, it uses the docker binary for CLI commands and dockerd for the daemon process.