6X336G - OpenShift Platform Overview Flashcards
Cloud Pak for Data is composed of integrated microservices on OpenShift. What is the benefit to this?
Resources are elastically managed with minimal downtime across a distributed system.
In brief, how can OpenShift be described as?
It is an enterprise-ready Kubernetes container platform with full-stack automated operations to manage hybrid cloud and multi-cloud deployments.
What is a container?
A container is an executable package of software that includes everything needed to run it, abstracting the operating system.
What does a container contain?
- Application binaries
2. Application dependencies
What is a microservice?
A microservice is a simple entity, performing a single function, or a service.
Briefly describe Kubernetes.
Key points:
- Open Source,
- Helps manage and control many containers.
- Helps manage the dependencies between each container and the interaction with each other.
OpenShift is built on/utilizes/abstracts away what container orchestration platform?
Kubernetes!
Describe Kubernetes’s use of Intelligent scheduling?
Key Points:
- Automatically places containers into the scheduling queue for resource consumption based on their resource requirements.
- Aims to increase the utilization of nodes while saving on platform resources.
Describe Kubernetes’s use of Self-healing?
Key points:
- Restarts containers that fail.
- Replaces and reschedules containers when nodes crash.
- Deletes containers that don’t respond to user-defined health check.
- Does not advertise them to clients until ready to use/serve.
What in the world does horizontal scaling mean, and how does Kubernetes do it?
Key points:
Scales applications up and down with
- A simple user-defined command.
- Using a UI GUI.
- Automatically based on CPU usage.
What is the idea of service discovery and how to does Kubernetes do it?
Kubernetes gives containers their own IP addresses and a single DNS name for a set of containers, and can load-balance across them
Describe automated rollback and rollout in K8S
Key points:
- If an error occurs during any progressive change to an application, Kubernetes will rollback the change for you.
What is meant by the stating that OpenShift is a layered system.
Key Points:
Within OpenShift, there are many abstractions and layers that have been built on top of others.
- Kubernetes manages containers.
- These containers provide the abstractions for packaging and creating linux-based, lightweight container images.
- OpenShift sits in between the service and routing layers.
Briefly describe what etcd process manager does.
etcd, is a reliable clustered key-value store that stores important metadata about each node in a cluster.
How does each node in a cluster communicate with each other?
Using a RESTful API.
Controllers or master nodes read each of the requests and apply changes.
What does scaling up a service mean, and what are its advantages?
Adjusting the number of pods. More pods generally means and increase in processing capacity.
Where can we backup data in case of problems encountered with our installations of upgrades?
We can back up and resotre the Persistent Volume Claims (VPC’s) in a project namespace.
