What is a replica set?

A replica set in MongoDB is a group of mongod processes that maintain the same data set. Replica sets provide redundancy and high availability, and are the basis for all production deployments. This section introduces replication in MongoDB as well as the components and architecture of replica sets.

KubernetesReplica Sets. Advertisements. Replica Set ensures how many replica of pod should be running. It can be considered as a replacement of replication controller.

Also, what is the difference between replica set and replication controller? Replica Set and Replication Controller do almost the same thing. Both of them ensure that a specified number of pod replicas are running at any given time. The difference comes with the usage of selectors to replicate pods. Replica Set use Set-Based selectors while replication controllers use Equity-Based selectors.

Accordingly, how do I remove replica set?

To delete a ReplicaSet and all of its Pods, use kubectl delete . The Garbage collector automatically deletes all of the dependent Pods by default.

What is the minimum recommended number of total nodes to have in a replica set?

The minimum recommended configuration for a replica set is a three member replica set with three data-bearing members: one primary and two secondary members. In some circumstances (such as you have a primary and a secondary but cost constraints prohibit adding another secondary), you may choose to include an arbiter.

What is DaemonSet?

DaemonSet. A DaemonSet ensures that all (or some) Nodes run a copy of a Pod. As nodes are added to the cluster, Pods are added to them. As nodes are removed from the cluster, those Pods are garbage collected. Deleting a DaemonSet will clean up the Pods it created.

What is the purpose of a replica set?

A replica set is a group of mongod instances that maintain the same data set. A replica set contains several data bearing nodes and optionally one arbiter node.

What is Kubernetes scaling?

Overview. When you deploy an application in GKE, you define how many replicas of the application you’d like to run. When you scale an application, you increase or decrease the number of replicas. Each replica of your application represents a Kubernetes Pod that encapsulates your application’s container(s).

How many containers a pod can run?

two Containers

What is Minikube?

Minikube is a tool that makes it easy to run Kubernetes locally. Minikube runs a single-node Kubernetes cluster inside a Virtual Machine (VM) on your laptop for users looking to try out Kubernetes or develop with it day-to-day.

What is Kubernetes controller?

In Kubernetes, a controller is a control loop that watches the shared state of the cluster through the API server and makes changes attempting to move the current state towards the desired state.

What is an ingress?

In Kubernetes, an Ingress is an object that allows access to your Kubernetes services from outside the Kubernetes cluster. You configure access by creating a collection of rules that define which inbound connections reach which services.

What are the possible states of a pod replica?

Once Pod is assigned to a node by scheduler, kubelet starts creating containers using container runtime.There are three possible states of containers: Waiting, Running and Terminated. To check state of container, you can use kubectl describe pod [POD_NAME] . State is displayed for each container within that Pod.

What is arbiter in MongoDB?

Arbiter: Arbiters are MongoDB instances that are part of a replica set but do not hold data. Arbiters participate in elections in order to break ties. If a replica set has an even number of members then you can add an arbiter.

How do I remove a replication controller from Kubernetes?

To delete a ReplicationController and all its pods, use kubectl delete . Kubectl will scale the ReplicationController to zero and wait for it to delete each pod before deleting the ReplicationController itself. If this kubectl command is interrupted, it can be restarted.

What is a worker node?

A node is a worker machine in Kubernetes, previously known as a minion . A node may be a VM or physical machine, depending on the cluster. Each node contains the services necessary to run pods and is managed by the master components. The services on a node include the container runtime, kubelet and kube-proxy.

What is container runtime?

A container runtime is software that executes containers and manages container images on a node. Today, the most widely known container runtime is Docker, but there are other container runtimes in the ecosystem, such as rkt, containerd, and lxd.

What is Kubernetes deployment?

Deployments represent a set of multiple, identical Pods with no unique identities. A Deployment runs multiple replicas of your application and automatically replaces any instances that fail or become unresponsive. Deployments are managed by the Kubernetes Deployment controller.

What is the name of the helm templating engine that runs in a pod in a Kubernetes cluster?

Tiller: The Helm server-side templating engine, which runs in a pod in a Kubernetes cluster. Tiller processes a chart to generate Kubernetes resource manifests, which are YAML-formatted files that describe a resource. YAML is a human-readable structured data format.