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Fix links in tutorials section

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Qiming Teng
2020-08-07 12:05:17 +08:00
parent 664464806c
commit c7e297ccab
5 changed files with 52 additions and 32 deletions
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content/en/docs/tutorials/stateful-application/cassandra.md
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@@ -7,9 +7,13 @@ weight: 30
---
<!-- overview -->
This tutorial shows you how to run [Apache Cassandra](http://cassandra.apache.org/) on Kubernetes. Cassandra, a database, needs persistent storage to provide data durability (application _state_). In this example, a custom Cassandra seed provider lets the database discover new Cassandra instances as they join the Cassandra cluster.
This tutorial shows you how to run [Apache Cassandra](https://cassandra.apache.org/) on Kubernetes.
Cassandra, a database, needs persistent storage to provide data durability (application _state_).
In this example, a custom Cassandra seed provider lets the database discover new Cassandra instances as they join the Cassandra cluster.
*StatefulSets* make it easier to deploy stateful applications into your Kubernetes cluster. For more information on the features used in this tutorial, see [StatefulSet](/docs/concepts/workloads/controllers/statefulset/).
*StatefulSets* make it easier to deploy stateful applications into your Kubernetes cluster.
For more information on the features used in this tutorial, see
[StatefulSet](/docs/concepts/workloads/controllers/statefulset/).
{{< note >}}
Cassandra and Kubernetes both use the term _node_ to mean a member of a cluster. In this
@@ -38,12 +42,17 @@ new Cassandra Pods as they appear inside your Kubernetes cluster.
{{< include "task-tutorial-prereqs.md" >}}
To complete this tutorial, you should already have a basic familiarity with {{< glossary_tooltip text="Pods" term_id="pod" >}}, {{< glossary_tooltip text="Services" term_id="service" >}}, and {{< glossary_tooltip text="StatefulSets" term_id="StatefulSet" >}}.
To complete this tutorial, you should already have a basic familiarity with
{{< glossary_tooltip text="Pods" term_id="pod" >}},
{{< glossary_tooltip text="Services" term_id="service" >}}, and
{{< glossary_tooltip text="StatefulSets" term_id="StatefulSet" >}}.
### Additional Minikube setup instructions
{{< caution >}}
[Minikube](/docs/getting-started-guides/minikube/) defaults to 1024MiB of memory and 1 CPU. Running Minikube with the default resource configuration results in insufficient resource errors during this tutorial. To avoid these errors, start Minikube with the following settings:
[Minikube](/docs/setup/learning-environment/minikube/) defaults to 1024MiB of memory and 1 CPU.
Running Minikube with the default resource configuration results in insufficient resource
errors during this tutorial. To avoid these errors, start Minikube with the following settings:
```shell
minikube start --memory 5120 --cpus=4
@@ -51,11 +60,11 @@ minikube start --memory 5120 --cpus=4
{{< /caution >}}
<!-- lessoncontent -->
## Creating a headless Service for Cassandra {#creating-a-cassandra-headless-service}
In Kubernetes, a {{< glossary_tooltip text="Service" term_id="service" >}} describes a set of {{< glossary_tooltip text="Pods" term_id="pod" >}} that perform the same task.
In Kubernetes, a {{< glossary_tooltip text="Service" term_id="service" >}} describes a set of
{{< glossary_tooltip text="Pods" term_id="pod" >}} that perform the same task.
The following Service is used for DNS lookups between Cassandra Pods and clients within your cluster:
@@ -83,14 +92,17 @@ NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
cassandra ClusterIP None <none> 9042/TCP 45s
```
If you don't see a Service named `cassandra`, that means creation failed. Read [Debug Services](/docs/tasks/debug-application-cluster/debug-service/) for help troubleshooting common issues.
If you don't see a Service named `cassandra`, that means creation failed. Read
[Debug Services](/docs/tasks/debug-application-cluster/debug-service/)
for help troubleshooting common issues.
## Using a StatefulSet to create a Cassandra ring
The StatefulSet manifest, included below, creates a Cassandra ring that consists of three Pods.
{{< note >}}
This example uses the default provisioner for Minikube. Please update the following StatefulSet for the cloud you are working with.
This example uses the default provisioner for Minikube.
Please update the following StatefulSet for the cloud you are working with.
{{< /note >}}
{{< codenew file="application/cassandra/cassandra-statefulset.yaml" >}}
@@ -182,7 +194,8 @@ Use `kubectl edit` to modify the size of a Cassandra StatefulSet.
kubectl edit statefulset cassandra
```
This command opens an editor in your terminal. The line you need to change is the `replicas` field. The following sample is an excerpt of the StatefulSet file:
This command opens an editor in your terminal. The line you need to change is the `replicas` field.
The following sample is an excerpt of the StatefulSet file:
```yaml
# Please edit the object below. Lines beginning with a '#' will be ignored,
@@ -225,10 +238,12 @@ Use `kubectl edit` to modify the size of a Cassandra StatefulSet.
## {{% heading "cleanup" %}}
Deleting or scaling a StatefulSet down does not delete the volumes associated with the StatefulSet. This setting is for your safety because your data is more valuable than automatically purging all related StatefulSet resources.
Deleting or scaling a StatefulSet down does not delete the volumes associated with the StatefulSet.
This setting is for your safety because your data is more valuable than automatically purging all related StatefulSet resources.
{{< warning >}}
Depending on the storage class and reclaim policy, deleting the *PersistentVolumeClaims* may cause the associated volumes to also be deleted. Never assume you’ll be able to access data if its volume claims are deleted.
Depending on the storage class and reclaim policy, deleting the *PersistentVolumeClaims* may cause the associated volumes
to also be deleted. Never assume you’ll be able to access data if its volume claims are deleted.
{{< /warning >}}
1. Run the following commands (chained together into a single command) to delete everything in the Cassandra StatefulSet: