Change Request limit of Postgresql

1. apply the request limit, this will trigger master & replica pod to restarted.

   kubectl apply -f cluster.yaml
   
   apiVersion: postgresql.cnpg.io/v1
   kind: Cluster
   metadata:
     name: echo-postgresql
     namespace: cnpg-system
   spec:
     resources:
       requests:
         cpu: 100m
         memory: 512Mi
       limits:
         cpu: 500m
         memory: 1Gi
   

2. After applied, replica will be restarted automatically

   $ kubectl get cluster
   NAME                                   AGE    INSTANCES   READY   STATUS                                       PRIMARY
   echo-postgresql                        10d    3           2       Waiting for the instances to become active   echo-postgresql-13
   
   kubectl get pod
   echo-postgresql-13                         1/1     Running    0          2d3h
   echo-postgresql-14                         0/1     Init:0/1   0          17s
   echo-postgresql-15                         1/1     Running    0          58s
   

3. Since we use unsupervised with switchover, primary will switchover automatically

   zufar.dhiyaullhaq@MacBookPro cnpg-learning % k get cluster                                                                                            
   NAME                                   AGE    INSTANCES   READY   STATUS                     PRIMARY
   echo-postgresql                        10d    3           3       Cluster in healthy state   echo-postgresql-14
   
   k get pod echo-postgresql-14 -oyaml | grep resources -A 10
   --
       resources:
         limits:
           cpu: 500m
           memory: 1Gi
         requests:
           cpu: 100m
           memory: 512Mi
   

Manifests

cluster.yaml

apiVersion: postgresql.cnpg.io/v1
kind: Cluster
metadata:
  name: echo-postgresql
  namespace: cnpg-system
spec:
  instances: 3
  storage:
    size: 20Gi
    storageClass: gtf-ack-essd-pl0-wait
  walStorage:
    size: 1Gi
    storageClass: gtf-ack-essd-pl0-wait
  primaryUpdateStrategy: unsupervised
  primaryUpdateMethod: switchover
  postgresql:
    synchronous:
      method: any
      number: 1
      dataDurability: required
  backup:
    target: prefer-standby
    volumeSnapshot:
      className: alibabacloud-disk-snapshot
      online: false
  resources:
    requests:
      cpu: 100m
      memory: 512Mi
    limits:
      cpu: 500m
      memory: 1Gi

https://cloudnative-pg.io/documentation/1.26/cloudnative-pg.v1/#postgresql-cnpg-io-v1-ClusterSpec