New to KubeDB? Please start here.
Vertical Scale PgBouncer
This guide will show you how to use KubeDB Ops-manager operator to update the resources of a PgBouncer.
Before You Begin
At first, you need to have a Kubernetes cluster, and the
kubectlcommand-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.Install
KubeDBProvisioner and Ops-manager operator in your cluster following the steps here.You should be familiar with the following
KubeDBconcepts:
To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.
$ kubectl create ns demo
namespace/demo created
Note: YAML files used in this tutorial are stored in docs/examples/pgbouncer directory of kubedb/docs repository.
Apply Vertical Scaling on PgBouncer
Here, we are going to deploy a PgBouncer using a supported version by KubeDB operator. Then we are going to apply vertical scaling on it.
Prepare Postgres
Prepare a KubeDB Postgres cluster using this tutorial, or you can use any externally managed postgres but in that case you need to create an appbinding yourself. In this tutorial we will use 3 node Postgres cluster named ha-postgres.
Prepare PgBouncer
Now, we are going to deploy a PgBouncer with version 1.18.0.
Deploy PgBouncer
In this section, we are going to deploy a PgBouncer. Then, in the next section we will update the resources using PgBouncerOpsRequest CRD. Below is the YAML of the PgBouncer CR that we are going to create,
apiVersion: kubedb.com/v1
kind: PgBouncer
metadata:
name: pb-vertical
namespace: demo
spec:
replicas: 1
version: "1.18.0"
database:
syncUsers: true
databaseName: "postgres"
databaseRef:
name: "ha-postgres"
namespace: demo
connectionPool:
poolMode: session
port: 5432
reservePoolSize: 5
maxClientConnections: 87
defaultPoolSize: 2
minPoolSize: 1
authType: md5
deletionPolicy: WipeOut
Let’s create the PgBouncer CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.12.18/docs/examples/pgbouncer/scaling/pb-vertical.yaml
pgbouncer.kubedb.com/pb-vertical created
Now, wait until pb-vertical has status Ready. i.e,
$ kubectl get pb -n demo
NAME TYPE VERSION STATUS AGE
pb-vertical kubedb.com/v1 1.18.0 Ready 17s
Let’s check the Pod containers resources,
$ kubectl get pod -n demo pb-vertical-0 -o json | jq '.spec.containers[].resources'
{
"limits": {
"memory": "1Gi"
},
"requests": {
"cpu": "500m",
"memory": "1Gi"
}
}
You can see the Pod has default resources which is assigned by the KubeDB operator.
We are now ready to apply the PgBouncerOpsRequest CR to update the resources of this pgbouncer.
Vertical Scaling
Here, we are going to update the resources of the pgbouncer to meet the desired resources after scaling.
Create PgBouncerOpsRequest
In order to update the resources of the pgbouncer, we have to create a PgBouncerOpsRequest CR with our desired resources. Below is the YAML of the PgBouncerOpsRequest CR that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: PgBouncerOpsRequest
metadata:
name: pgbouncer-scale-vertical
namespace: demo
spec:
type: VerticalScaling
databaseRef:
name: pb-vertical
verticalScaling:
pgbouncer:
resources:
requests:
memory: "2Gi"
cpu: "1"
limits:
memory: "2Gi"
cpu: "1"
timeout: 5m
apply: IfReady
Here,
spec.databaseRef.namespecifies that we are performing vertical scaling operation onpb-verticalpgbouncer.spec.typespecifies that we are performingVerticalScalingon our database.spec.VerticalScaling.pgbouncerspecifies the desired resources after scaling.- Have a look here on the respective sections to understand the
timeout&applyfields.
Let’s create the PgBouncerOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.12.18/docs/examples/pgbouncer/scaling/pb-vertical-ops.yaml
pgbounceropsrequest.ops.kubedb.com/pgbouncer-scale-vertical created
Verify PgBouncer resources updated successfully
If everything goes well, KubeDB Ops-manager operator will update the resources of PgBouncer object and related PetSet and Pods.
Let’s wait for PgBouncerOpsRequest to be Successful. Run the following command to watch PgBouncerOpsRequest CR,
$ kubectl get pgbounceropsrequest -n demo
Every 2.0s: kubectl get pgbounceropsrequest -n demo
NAME TYPE STATUS AGE
pgbouncer-scale-vertical VerticalScaling Successful 3m42s
We can see from the above output that the PgBouncerOpsRequest has succeeded. If we describe the PgBouncerOpsRequest we will get an overview of the steps that were followed to scale the pgbouncer.
$ kubectl describe pgbounceropsrequest -n demo pgbouncer-scale-vertical
Name: pgbouncer-scale-vertical
Namespace: demo
Labels: <none>
Annotations: <none>
API Version: ops.kubedb.com/v1alpha1
Kind: PgBouncerOpsRequest
Metadata:
Creation Timestamp: 2024-11-27T12:35:02Z
Generation: 1
Resource Version: 55854
UID: 567e12f9-b561-4fea-af91-1ed9412a0d74
Spec:
Apply: IfReady
Database Ref:
Name: pb-vertical
Timeout: 5m
Type: VerticalScaling
Vertical Scaling:
Pgbouncer:
Resources:
Limits:
Cpu: 1
Memory: 2Gi
Requests:
Cpu: 1
Memory: 2Gi
Status:
Conditions:
Last Transition Time: 2024-11-27T12:35:02Z
Message: Controller has started to Progress with VerticalScaling of PgBouncerOpsRequest: demo/pgbouncer-scale-vertical
Observed Generation: 1
Reason: Running
Status: True
Type: Running
Last Transition Time: 2024-11-27T12:35:08Z
Message: Successfully updated Petset resource
Observed Generation: 1
Reason: UpdatePetSets
Status: True
Type: UpdatePetSets
Last Transition Time: 2024-11-27T12:35:13Z
Message: get pod; ConditionStatus:True; PodName:pb-vertical-0
Observed Generation: 1
Status: True
Type: GetPod--pb-vertical-0
Last Transition Time: 2024-11-27T12:35:13Z
Message: evict pod; ConditionStatus:True; PodName:pb-vertical-0
Observed Generation: 1
Status: True
Type: EvictPod--pb-vertical-0
Last Transition Time: 2024-11-27T12:35:18Z
Message: check replica func; ConditionStatus:True; PodName:pb-vertical-0
Observed Generation: 1
Status: True
Type: CheckReplicaFunc--pb-vertical-0
Last Transition Time: 2024-11-27T12:35:18Z
Message: check pod ready; ConditionStatus:True; PodName:pb-vertical-0
Observed Generation: 1
Status: True
Type: CheckPodReady--pb-vertical-0
Last Transition Time: 2024-11-27T12:35:38Z
Message: check pg bouncer running; ConditionStatus:True; PodName:pb-vertical-0
Observed Generation: 1
Status: True
Type: CheckPgBouncerRunning--pb-vertical-0
Last Transition Time: 2024-11-27T12:35:43Z
Message: Vertical scaling Up performed successfully in PgBouncer: demo/pb-vertical for PgBouncerOpsRequest: pgbouncer-scale-vertical
Observed Generation: 1
Reason: VerticalScaleSucceeded
Status: True
Type: VerticalScale
Last Transition Time: 2024-11-27T12:35:53Z
Message: Controller has successfully completed with VerticalScaling of PgBouncerOpsRequest: demo/pgbouncer-scale-vertical
Observed Generation: 1
Reason: Successful
Status: True
Type: Successful
Observed Generation: 1
Phase: Successful
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Starting 81s KubeDB Ops-manager Operator Start processing for PgBouncerOpsRequest: demo/pgbouncer-scale-vertical
Normal Starting 81s KubeDB Ops-manager Operator Pausing PgBouncer databse: demo/pb-vertical
Normal Successful 81s KubeDB Ops-manager Operator Successfully paused PgBouncer database: demo/pb-vertical for PgBouncerOpsRequest: pgbouncer-scale-vertical
Warning get pod; ConditionStatus:True; PodName:pb-vertical-0 70s KubeDB Ops-manager Operator get pod; ConditionStatus:True; PodName:pb-vertical-0
Warning evict pod; ConditionStatus:True; PodName:pb-vertical-0 70s KubeDB Ops-manager Operator evict pod; ConditionStatus:True; PodName:pb-vertical-0
Warning check replica func; ConditionStatus:True; PodName:pb-vertical-0 65s KubeDB Ops-manager Operator check replica func; ConditionStatus:True; PodName:pb-vertical-0
Warning check pod ready; ConditionStatus:True; PodName:pb-vertical-0 65s KubeDB Ops-manager Operator check pod ready; ConditionStatus:True; PodName:pb-vertical-0
Warning check pg bouncer running; ConditionStatus:False; PodName:pb-vertical-0 55s KubeDB Ops-manager Operator check pg bouncer running; ConditionStatus:False; PodName:pb-vertical-0
Warning check replica func; ConditionStatus:True; PodName:pb-vertical-0 55s KubeDB Ops-manager Operator check replica func; ConditionStatus:True; PodName:pb-vertical-0
Warning check pod ready; ConditionStatus:True; PodName:pb-vertical-0 55s KubeDB Ops-manager Operator check pod ready; ConditionStatus:True; PodName:pb-vertical-0
Warning check replica func; ConditionStatus:True; PodName:pb-vertical-0 45s KubeDB Ops-manager Operator check replica func; ConditionStatus:True; PodName:pb-vertical-0
Warning check pod ready; ConditionStatus:True; PodName:pb-vertical-0 45s KubeDB Ops-manager Operator check pod ready; ConditionStatus:True; PodName:pb-vertical-0
Warning check pg bouncer running; ConditionStatus:True; PodName:pb-vertical-0 45s KubeDB Ops-manager Operator check pg bouncer running; ConditionStatus:True; PodName:pb-vertical-0
Normal Successful 40s KubeDB Ops-manager Operator Vertical scaling Up performed successfully in PgBouncer: demo/pb-vertical for PgBouncerOpsRequest: pgbouncer-scale-vertical
Normal Starting 30s KubeDB Ops-manager Operator Resuming PgBouncer database: demo/pb-vertical
Normal Successful 30s KubeDB Ops-manager Operator Successfully resumed PgBouncer database: demo/pb-vertical
Normal Starting 30s KubeDB Ops-manager Operator Resuming PgBouncer database: demo/pb-vertical
Normal Successful 30s KubeDB Ops-manager Operator Successfully resumed PgBouncer database: demo/pb-vertical
Normal Successful 30s KubeDB Ops-manager Operator Controller has Successfully scaled the PgBouncer database: demo/pb-vertical
Now, we are going to verify from the Pod yaml whether the resources of the pgbouncer has updated to meet up the desired state, Let’s check,
$ kubectl get pod -n demo pb-vertical-0 -o json | jq '.spec.containers[].resources'
{
"limits": {
"cpu": "1",
"memory": "2Gi"
},
"requests": {
"cpu": "1",
"memory": "2Gi"
}
}
The above output verifies that we have successfully scaled up the resources of the PgBouncer.
Cleaning Up
To clean up the Kubernetes resources created by this tutorial, run:
kubectl delete pb -n demo pb-vertical
kubectl delete pgbounceropsrequest -n demo pgbouncer-scale-vertical