Consolidate YAML files [part-6] (#9261)
* Consolidate YAML files [part-6] This PR relocates the YAML files used by the stateful application examples. * Update examples_test.go
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@@ -15,7 +15,10 @@ Deploying stateful distributed applications, like Cassandra, within a clustered
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The Pods use the [`gcr.io/google-samples/cassandra:v13`](https://github.com/kubernetes/examples/blob/master/cassandra/image/Dockerfile)
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image from Google's [container registry](https://cloud.google.com/container-registry/docs/).
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The docker image above is based on [debian-base](https://github.com/kubernetes/kubernetes/tree/master/build/debian-base) and includes OpenJDK 8. This image includes a standard Cassandra installation from the Apache Debian repo. By using environment variables you can change values that are inserted into `cassandra.yaml`.
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The docker image above is based on [debian-base](https://github.com/kubernetes/kubernetes/tree/master/build/debian-base)
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and includes OpenJDK 8.
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This image includes a standard Cassandra installation from the Apache Debian repo.
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By using environment variables you can change values that are inserted into `cassandra.yaml`.
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| ENV VAR | DEFAULT VALUE |
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| ------------- |:-------------: |
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@@ -38,7 +41,8 @@ To complete this tutorial, you should already have a basic familiarity with [Pod
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* [Install and Configure](/docs/tasks/tools/install-kubectl/) the `kubectl` command line
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* Download [cassandra-service.yaml](/docs/tutorials/stateful-application/cassandra/cassandra-service.yaml) and [cassandra-statefulset.yaml](/docs/tutorials/stateful-application/cassandra/cassandra-statefulset.yaml)
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* Download [cassandra-service.yaml](/examples/application/cassandra/cassandra-service.yaml)
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and [cassandra-statefulset.yaml](/examples/application/cassandra/cassandra-statefulset.yaml)
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* Have a supported Kubernetes Cluster running
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@@ -64,12 +68,14 @@ A Kubernetes [Service](/docs/concepts/services-networking/service/) describes a
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The following `Service` is used for DNS lookups between Cassandra Pods and clients within the Kubernetes Cluster.
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{{< codenew file="application/cassandra/cassandra-service.yaml" >}}
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1. Launch a terminal window in the directory you downloaded the manifest files.
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2. Create a `Service` to track all Cassandra StatefulSet Nodes from the `cassandra-service.yaml` file:
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1. Create a `Service` to track all Cassandra StatefulSet Nodes from the `cassandra-service.yaml` file:
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kubectl create -f cassandra-service.yaml
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{{< code file="cassandra/cassandra-service.yaml" >}}
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```shell
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kubectl create -f https://k8s.io/examples/application/cassandra/cassandra-service.yaml
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```
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### Validating (optional)
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@@ -92,106 +98,127 @@ The StatefulSet manifest, included below, creates a Cassandra ring that consists
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**Note:** This example uses the default provisioner for Minikube. Please update the following StatefulSet for the cloud you are working with.
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{{< /note >}}
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{{< codenew file="application/cassandra/cassandra-statefulset.yaml" >}}
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1. Update the StatefulSet if necessary.
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2. Create the Cassandra StatefulSet from the `cassandra-statefulset.yaml` file:
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1. Create the Cassandra StatefulSet from the `cassandra-statefulset.yaml` file:
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kubectl create -f cassandra-statefulset.yaml
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{{< code file="cassandra/cassandra-statefulset.yaml" >}}
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```shell
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kubectl create -f https://k8s.io/examples/application/cassandra/cassandra-statefulset.yaml
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```
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## Validating The Cassandra StatefulSet
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1. Get the Cassandra StatefulSet:
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kubectl get statefulset cassandra
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```
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kubectl get statefulset cassandra
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```
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The response should be
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The response should be
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NAME DESIRED CURRENT AGE
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cassandra 3 0 13s
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```
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NAME DESIRED CURRENT AGE
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cassandra 3 0 13s
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```
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The StatefulSet resource deploys Pods sequentially.
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The StatefulSet resource deploys Pods sequentially.
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2. Get the Pods to see the ordered creation status:
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1. Get the Pods to see the ordered creation status:
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kubectl get pods -l="app=cassandra"
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```shell
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kubectl get pods -l="app=cassandra"
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```
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The response should be
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NAME READY STATUS RESTARTS AGE
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cassandra-0 1/1 Running 0 1m
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cassandra-1 0/1 ContainerCreating 0 8s
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The response should be
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{{< note >}}
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**Note:** It can take up to ten minutes for all three Pods to deploy.
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{{< /note >}}
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```
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NAME READY STATUS RESTARTS AGE
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cassandra-0 1/1 Running 0 1m
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cassandra-1 0/1 ContainerCreating 0 8s
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```
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Once all Pods are deployed, the same command returns:
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**Note:** It can take up to ten minutes for all three Pods to deploy.
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NAME READY STATUS RESTARTS AGE
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cassandra-0 1/1 Running 0 10m
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cassandra-1 1/1 Running 0 9m
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cassandra-2 1/1 Running 0 8m
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Once all Pods are deployed, the same command returns:
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3. Run the Cassandra utility nodetool to display the status of the ring.
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```
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NAME READY STATUS RESTARTS AGE
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cassandra-0 1/1 Running 0 10m
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cassandra-1 1/1 Running 0 9m
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cassandra-2 1/1 Running 0 8m
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```
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kubectl exec cassandra-0 -- nodetool status
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1. Run the Cassandra utility nodetool to display the status of the ring.
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The response is:
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```shell
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kubectl exec cassandra-0 -- nodetool status
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```
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Datacenter: DC1-K8Demo
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======================
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Status=Up/Down
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|/ State=Normal/Leaving/Joining/Moving
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-- Address Load Tokens Owns (effective) Host ID Rack
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UN 172.17.0.5 83.57 KiB 32 74.0% e2dd09e6-d9d3-477e-96c5-45094c08db0f Rack1-K8Demo
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UN 172.17.0.4 101.04 KiB 32 58.8% f89d6835-3a42-4419-92b3-0e62cae1479c Rack1-K8Demo
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UN 172.17.0.6 84.74 KiB 32 67.1% a6a1e8c2-3dc5-4417-b1a0-26507af2aaad Rack1-K8Demo
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The response is:
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```
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Datacenter: DC1-K8Demo
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======================
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Status=Up/Down
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|/ State=Normal/Leaving/Joining/Moving
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-- Address Load Tokens Owns (effective) Host ID Rack
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UN 172.17.0.5 83.57 KiB 32 74.0% e2dd09e6-d9d3-477e-96c5-45094c08db0f Rack1-K8Demo
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UN 172.17.0.4 101.04 KiB 32 58.8% f89d6835-3a42-4419-92b3-0e62cae1479c Rack1-K8Demo
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UN 172.17.0.6 84.74 KiB 32 67.1% a6a1e8c2-3dc5-4417-b1a0-26507af2aaad Rack1-K8Demo
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```
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## Modifying the Cassandra StatefulSet
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Use `kubectl edit` to modify the size of a Cassandra StatefulSet.
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1. Run the following command:
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kubectl edit statefulset cassandra
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```
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kubectl edit statefulset cassandra
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```
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This command opens an editor in your terminal. The line you need to change is the `replicas` field.
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This command opens an editor in your terminal. The line you need to change is the `replicas` field.
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{{< note >}}
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**Note:** The following sample is an excerpt of the StatefulSet file.
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{{< /note >}}
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**Note:** The following sample is an excerpt of the StatefulSet file.
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# Please edit the object below. Lines beginning with a '#' will be ignored,
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# and an empty file will abort the edit. If an error occurs while saving this file will be
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# reopened with the relevant failures.
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#
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apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
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kind: StatefulSet
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metadata:
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creationTimestamp: 2016-08-13T18:40:58Z
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generation: 1
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labels:
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app: cassandra
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name: cassandra
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namespace: default
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resourceVersion: "323"
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selfLink: /apis/apps/v1/namespaces/default/statefulsets/cassandra
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uid: 7a219483-6185-11e6-a910-42010a8a0fc0
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spec:
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replicas: 3
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```
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# Please edit the object below. Lines beginning with a '#' will be ignored,
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# and an empty file will abort the edit. If an error occurs while saving this file will be
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# reopened with the relevant failures.
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#
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apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
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kind: StatefulSet
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metadata:
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creationTimestamp: 2016-08-13T18:40:58Z
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generation: 1
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labels:
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app: cassandra
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name: cassandra
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namespace: default
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resourceVersion: "323"
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selfLink: /apis/apps/v1/namespaces/default/statefulsets/cassandra
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uid: 7a219483-6185-11e6-a910-42010a8a0fc0
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spec:
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replicas: 3
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```
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2. Change the number of replicas to 4, and then save the manifest.
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1. Change the number of replicas to 4, and then save the manifest.
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The StatefulSet now contains 4 Pods.
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3. Get the Cassandra StatefulSet to verify:
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1. Get the Cassandra StatefulSet to verify:
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kubectl get statefulset cassandra
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```shell
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kubectl get statefulset cassandra
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```
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The response should be
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The response should be
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NAME DESIRED CURRENT AGE
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cassandra 4 4 36m
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```
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NAME DESIRED CURRENT AGE
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cassandra 4 4 36m
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```
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{{% /capture %}}
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@@ -204,19 +231,24 @@ Deleting or scaling a StatefulSet down does not delete the volumes associated wi
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1. Run the following commands to delete everything in a `StatefulSet`:
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grace=$(kubectl get po cassandra-0 -o=jsonpath='{.spec.terminationGracePeriodSeconds}') \
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```shell
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grace=$(kubectl get po cassandra-0 -o=jsonpath='{.spec.terminationGracePeriodSeconds}') \
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&& kubectl delete statefulset -l app=cassandra \
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&& echo "Sleeping $grace" \
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&& sleep $grace \
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&& kubectl delete pvc -l app=cassandra
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```
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2. Run the following command to delete the Cassandra `Service`.
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1. Run the following command to delete the Cassandra `Service`.
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kubectl delete service -l app=cassandra
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```
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kubectl delete service -l app=cassandra
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```
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{{% /capture %}}
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{{% capture whatsnext %}}
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* Learn how to [Scale a StatefulSet](/docs/tasks/run-application/scale-stateful-set/).
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* Learn more about the [KubernetesSeedProvider](https://github.com/kubernetes/examples/blob/master/cassandra/java/src/main/java/io/k8s/cassandra/KubernetesSeedProvider.java)
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* See more custom [Seed Provider Configurations](https://git.k8s.io/examples/cassandra/java/README.md)
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