Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Rename architecture section #16286

Merged
merged 2 commits into from
Oct 9, 2019
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion content/en/docs/concepts/architecture/_index.md
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
---
title: "Kubernetes Architecture"
title: "Cluster Architecture"
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

My only gripe with this is that, interestingly enough, the term "cluster" isn't really defined in the Concepts pages. The "What is Kubernetes" page doesn't mention "cluster" anywhere. The "Kubernetes Components" page mentions cluster plenty of times but doesn't actually define it. The Glossary does have a term for "cluster", though:

A set of machines, called nodes, that run containerized applications managed by Kubernetes. A cluster has at least one worker node and at least one master node.

So, while I totally agree that "Kubernetes" is redundant, I guess I'd prefer to replace "Cluster" with "System" or add a "Concepts -> Cluster" page that explains what we mean by "Cluster" first. Thoughts?

Copy link
Contributor Author

@sftim sftim Sep 10, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Let's add cluster to the glossary, either as well or instead of what you're suggesting @jaypipes
Oops, misread!

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Cluster is in the glossary already with the definition above. I guess what I'm pointing out is that the Concepts section doesn't really have anything that says what a cluster is even though the term cluster is used in a number of the Concepts pages. So, perhaps good to modify the "What is Kubernetes" page to define what the term "cluster" refers to, and then it would be good to go forward with this PR change that changes the "Kubernetes Architecture" title to "Cluster Architecture". Hope that makes sense.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I can revise this PR to do that.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@jaypipes how about this (revised) approach?
If you think it's still short of the mark, please do say so.

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@sftim It looks like you've addressed the feedback from @jaypipes, and that this PR is headed in the right direction, so I'll /approve and @jaypipes can /lgtm if he agrees.

/approve

weight: 30
---

9 changes: 6 additions & 3 deletions content/en/docs/concepts/overview/components.md
Original file line number Diff line number Diff line change
Expand Up @@ -10,8 +10,11 @@ card:
---

{{% capture overview %}}
This document outlines the various binary components needed to
deliver a functioning Kubernetes cluster.
When you deploy Kubernetes, you get a cluster.
{{< glossary_definition term_id="cluster" length="all" prepend="A cluster is">}}

This document outlines the various components you need to have
a complete and working Kubernetes cluster.
{{% /capture %}}

{{% capture body %}}
Expand Down Expand Up @@ -109,7 +112,7 @@ about containers in a central database, and provides a UI for browsing that data

### Cluster-level Logging

A [Cluster-level logging](/docs/concepts/cluster-administration/logging/) mechanism is responsible for
A [cluster-level logging](/docs/concepts/cluster-administration/logging/) mechanism is responsible for
saving container logs to a central log store with search/browsing interface.

{{% /capture %}}
Expand Down
8 changes: 4 additions & 4 deletions content/en/docs/concepts/overview/what-is-kubernetes.md
Original file line number Diff line number Diff line change
Expand Up @@ -29,13 +29,13 @@ Early on, organizations ran applications on physical servers. There was no way t

**Virtualized deployment era:** As a solution, virtualization was introduced. It allows you to run multiple Virtual Machines (VMs) on a single physical server's CPU. Virtualization allows applications to be isolated between VMs and provides a level of security as the information of one application cannot be freely accessed by another application.

Virtualization allows better utilization of resources in a physical server and allows better scalability because an application can be added or updated easily, reduces hardware costs, and much more.
Virtualization allows better utilization of resources in a physical server and allows better scalability because an application can be added or updated easily, reduces hardware costs, and much more. With virtualization you can present a set of physical resources as a cluster of disposable virtual machines.

Each VM is a full machine running all the components, including its own operating system, on top of the virtualized hardware.

**Container deployment era:** Containers are similar to VMs, but they have relaxed isolation properties to share the Operating System (OS) among the applications. Therefore, containers are considered lightweight. Similar to a VM, a container has its own filesystem, CPU, memory, process space, and more. As they are decoupled from the underlying infrastructure, they are portable across clouds and OS distributions.

Containers are becoming popular because they have many benefits. Some of the container benefits are listed below:
Containers have become popular because they provide extra benefits, such as:

* Agile application creation and deployment: increased ease and efficiency of container image creation compared to VM image use.
* Continuous development, integration, and deployment: provides for reliable and frequent container image build and deployment with quick and easy rollbacks (due to image immutability).
Expand All @@ -52,7 +52,7 @@ Containers are becoming popular because they have many benefits. Some of the con

Containers are a good way to bundle and run your applications. In a production environment, you need to manage the containers that run the applications and ensure that there is no downtime. For example, if a container goes down, another container needs to start. Wouldn't it be easier if this behavior was handled by a system?

That's how Kubernetes comes to the rescue! Kubernetes provides you with a framework to run distributed systems resiliently. It takes care of your scaling requirements, failover, deployment patterns, and more. For example, Kubernetes can easily manage a canary deployment for your system.
That's how Kubernetes comes to the rescue! Kubernetes provides you with a framework to run distributed systems resiliently. It takes care of scaling and failover for your application, provides deployment patterns, and more. For example, Kubernetes can easily manage a canary deployment for your system.

Kubernetes provides you with:

Expand All @@ -63,7 +63,7 @@ Kubernetes allows you to automatically mount a storage system of your choice, su
* **Automated rollouts and rollbacks**
You can describe the desired state for your deployed containers using Kubernetes, and it can change the actual state to the desired state at a controlled rate. For example, you can automate Kubernetes to create new containers for your deployment, remove existing containers and adopt all their resources to the new container.
* **Automatic bin packing**
Kubernetes allows you to specify how much CPU and memory (RAM) each container needs. When containers have resource requests specified, Kubernetes can make better decisions to manage the resources for containers.
You provide Kubernetes with a cluster of nodes that it can use to run containerized tasks. You tell Kubernetes how much CPU and memory (RAM) each container needs. Kubernetes can fit containers onto your nodes to make the best use of your resources.
* **Self-healing**
Kubernetes restarts containers that fail, replaces containers, kills containers that don’t respond to your user-defined health check, and doesn’t advertise them to clients until they are ready to serve.
* **Secret and configuration management**
Expand Down