Upgrade a Greenplum Cluster

This topic describes how to upgrade a Greenplum for Kubernetes cluster to the latest version of the Pivotal Greenplum software. The process of upgrading a Greenplum cluster involves deleting the existing cluster, and then re-creating the cluster deployment using the same manifest file. You re-use any existing persistent volumes when re-creating the cluster with the new Operator.

Prerequisites

Ensure that you have first upgraded the Greenplum Operator to the new version using the instructions in Upgrade the Greenplum Operator.
Create a backup of your existing Greenplum for Kubernetes cluster.

Procedure

Follow these steps to upgrade a Greenplum for Kubernetes cluster to use the new Pivotal Greenplum software:

Navigate to the workspace directory of the Greenplum for Kuberenetes installation (or to the location of the Kubernetes manifest that you used to deploy the cluster). For example:
```
$ cd ./greenplum-for-kubernetes-*/workspace
```
Execute the kubectl delete command, specifying the manifest that you used to deploy the cluster. For example:
```
$ kubectl delete -f ./my-gp-instance.yaml
```
kubectl stops the Greenplum for Kubernetes instance and deletes the kubernetes resources for the Greenplum deployment.

Use kubectl to monitor the progress of terminating Greenplum resources in your cluster. For example, if your cluster deployment was named my-greenplum:

$ kubectl get all -l greenplum-cluster=my-greenplum

NAME                                     READY     STATUS        RESTARTS   AGE
pod/greenplum-operator-7b5ddcb79-vnwvc   1/1       Running       0          9m
pod/master-0                             0/1       Terminating   0          5m
pod/segment-a-0                          0/1       Terminating   0          5m
pod/segment-a-1                          0/1       Terminating   0          5m
pod/segment-b-0                          0/1       Terminating   0          5m

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   26m

NAME                                 DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/greenplum-operator   1         1         1            1           9m

NAME                                           DESIRED   CURRENT   READY     AGE
replicaset.apps/greenplum-operator-7b5ddcb79   1         1         1         9m

The deletion process is complete when the segment pods are no longer available (and no resources remain):

$ kubectl get all -l greenplum-cluster=my-greenplum

No resources found.

The Greenplum Operator should remain for future deployments:

$ kubectl get all

NAME                                     READY     STATUS    RESTARTS   AGE
pod/greenplum-operator-7b5ddcb79-vnwvc   1/1       Running   0          34m

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   50m

NAME                                 DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/greenplum-operator   1         1         1            1           34m

NAME                                           DESIRED   CURRENT   READY     AGE
replicaset.apps/greenplum-operator-7b5ddcb79   1         1         1         34m

Use kubectl apply and specify your manifest file to send the deployment request to the Greenplum Operator. For example, to use the sample my-gp-instance.yaml file:
```
$ kubectl apply -f ./my-gp-instance.yaml 
```
```
greenplumcluster.greenplum.pivotal.io/my-greenplum created
```
The Greenplum Operator deploys the necessary Greenplum resources according to your specification, using the existing Persistent Volume Claims as-is with their available data.

Use kubectl get all -l greenplum-cluster=<your Greenplum cluster instance name> and wait until all Greenplum cluster pods have the status Running:

$ watch kubectl get all -l greenplum-cluster=my-greenplum

NAME              READY     STATUS    RESTARTS   AGE
pod/master-0      1/1       Running   1          2d
pod/master-1      1/1       Running   1          2d
pod/segment-a-0   1/1       Running   0          23h
pod/segment-b-0   1/1       Running   1          2d

NAME                TYPE           CLUSTER-IP   EXTERNAL-IP   PORT(S)          AGE
service/agent       ClusterIP      None         <none>        22/TCP           2d
service/greenplum   LoadBalancer   10.99.14.1   <pending>     5432:30430/TCP   2d

NAME                         DESIRED   CURRENT   AGE
statefulset.apps/master      2         2         2d
statefulset.apps/segment-a   1         1         2d
statefulset.apps/segment-b   1         1         2d

At this point, the upgraded cluster is available. If you are using a persistent storageClass, the updated cluster is created with the same Persistent Volume Claims (PVCs) and data.

Describe your Greenplum cluster to observe that the update succeeded.

$ kubectl describe greenplumClusters/my-greenplum

Name:         my-greenplum
Namespace:    default
Labels:       <none>
Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                {"apiVersion":"greenplum.pivotal.io/v1","kind":"GreenplumCluster","metadata":{"annotations":{},"name":"my-greenplum","namespace":"default"...
API Version:  greenplum.pivotal.io/v1
Kind:         GreenplumCluster
Metadata:
  Creation Timestamp:  2019-01-10T22:15:40Z
  Generation:          1
  Resource Version:    28403
  Self Link:           /apis/greenplum.pivotal.io/v1/namespaces/default/greenplumclusters/my-greenplum
  UID:                 43842f53-1525-11e9-941d-080027530600
Spec:
  Master And Standby:
    Cpu:                        0.5
    Host Based Authentication:  # host   all   gpadmin   1.2.3.4/32   trust
# host   all   gpuser    0.0.0.0/0   md5

    Memory:              800Mi
    Storage:             1G
    Storage Class Name:  standard
    Worker Selector:
  Segments:
    Cpu:                    0.5
    Memory:                 800Mi
    Primary Segment Count:  1
    Storage:                2G
    Storage Class Name:     standard
    Worker Selector:
Status:
  Instance Image:  greenplum-for-kubernetes:latest
  Phase:           Running
Events:
  Type    Reason   Age   From               Message
  ----    ------   ----  ----               -------
  Normal  created  12s   greenplumOperator  greenplumCluster created
  Normal  updated  12s   greenplumOperator  greenplumCluster updated successfully

The Phase should be Running and the Events should match the output above.

Start the cluster to complete the upgrade process:

kubectl exec -it master-0 -- bash -c "source /opt/gpdb/greenplum_path.sh; gpstart"