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Horizontal Scale MSSQLServer Cluster
This guide will show you how to use KubeDB Ops Manager to increase/decrease the number of replicas of a MSSQLServer Cluster.
Before You Begin
You need to have a Kubernetes cluster, and the kubectl command-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.
Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here. Make sure install with helm command including
--set global.featureGates.MSSQLServer=trueto ensure MSSQLServer CRD installation.To configure TLS/SSL in
MSSQLServer,KubeDBusescert-managerto issue certificates. So first you have to make sure that the cluster hascert-managerinstalled. To installcert-managerin your cluster following 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/mssqlserver/scaling/horizontal-scaling directory of kubedb/doc repository.
Apply Horizontal Scaling on MSSQLServer Cluster
Here, we are going to deploy a MSSQLServer Cluster using a supported version by KubeDB operator. Then we are going to apply horizontal scaling on it.
Prepare Cluster
At first, we are going to deploy a Cluster server with 2 replicas. Then, we are going to add two additional replicas through horizontal scaling. Finally, we will remove 1 replica from the cluster again via horizontal scaling.
Find supported MSSQLServer Version:
When you have installed KubeDB, it has created MSSQLServerVersion CR for all supported MSSQLServer versions. Let’s check the supported MSSQLServer versions,
$ kubectl get mssqlserverversion
NAME VERSION DB_IMAGE DEPRECATED AGE
2022-cu12 2022 mcr.microsoft.com/mssql/server:2022-CU12-ubuntu-22.04 176m
2022-cu14 2022 mcr.microsoft.com/mssql/server:2022-CU14-ubuntu-22.04 176m
The version above that does not show DEPRECATED true is supported by KubeDB for MSSQLServer. You can use any non-deprecated version. Here, we are going to create a MSSQLServer Cluster using MSSQLServer 2022-cu12.
Deploy MSSQLServer Cluster:
First, an issuer needs to be created, even if TLS is not enabled for SQL Server. The issuer will be used to configure the TLS-enabled Wal-G proxy server, which is required for the SQL Server backup and restore operations.
Create Issuer/ClusterIssuer
Now, we are going to create an example Issuer that will be used throughout the duration of this tutorial. Alternatively, you can follow this cert-manager tutorial to create your own Issuer. By following the below steps, we are going to create our desired issuer,
- Start off by generating our ca-certificates using openssl,
openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./ca.key -out ./ca.crt -subj "/CN=MSSQLServer/O=kubedb"
- Create a secret using the certificate files we have just generated,
$ kubectl create secret tls mssqlserver-ca --cert=ca.crt --key=ca.key --namespace=demo
secret/mssqlserver-ca created
Now, we are going to create an Issuer using the mssqlserver-ca secret that contains the ca-certificate we have just created. Below is the YAML of the Issuer CR that we are going to create,
apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
name: mssqlserver-ca-issuer
namespace: demo
spec:
ca:
secretName: mssqlserver-ca
Let’s create the Issuer CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2025.12.9-rc.0/docs/examples/mssqlserver/ag-cluster/mssqlserver-ca-issuer.yaml
issuer.cert-manager.io/mssqlserver-ca-issuer created
In this section, we are going to deploy a MSSQLServer Cluster with 2 replicas. Then, in the next section we will scale up the cluster using horizontal scaling. Below is the YAML of the MSSQLServer CR that we are going to create,
apiVersion: kubedb.com/v1alpha2
kind: MSSQLServer
metadata:
name: mssql-ag-cluster
namespace: demo
spec:
version: "2022-cu12"
replicas: 2
topology:
mode: AvailabilityGroup
availabilityGroup:
databases:
- agdb1
- agdb2
tls:
issuerRef:
name: mssqlserver-ca-issuer
kind: Issuer
apiGroup: "cert-manager.io"
clientTLS: false
podTemplate:
spec:
containers:
- name: mssql
env:
- name: ACCEPT_EULA
value: "Y"
- name: MSSQL_PID
value: Evaluation # Change it
resources:
requests:
cpu: "500m"
memory: "1.5Gi"
limits:
cpu: 1
memory: "2Gi"
storageType: Durable
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
deletionPolicy: WipeOut
Let’s create the MSSQLServer CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2025.12.9-rc.0/docs/examples/mssqlserver/scaling/horizontal-scaling/mssql-ag-cluster.yaml
mssqlserver.kubedb.com/mssql-ag-cluster created
Wait for the cluster to be ready:
KubeDB operator watches for MSSQLServer objects using Kubernetes API. When a MSSQLServer object is created, KubeDB operator will create a new PetSet, Services, and Secrets, etc. A secret called mssql-ag-cluster-auth (format: {mssqlserver-object-name}-auth) will be created storing the password for mssqlserver superuser.
Now, watch MSSQLServer is going to Running state and also watch PetSet and its pod is created and going to Running state,
$ watch kubectl get ms,petset,pods -n demo
Every 2.0s: kubectl get ms,petset,pods -n demo
NAME VERSION STATUS AGE
mssqlserver.kubedb.com/mssql-ag-cluster 2022-cu12 Ready 2m52s
NAME AGE
petset.apps.k8s.appscode.com/mssql-ag-cluster 2m11s
NAME READY STATUS RESTARTS AGE
pod/mssql-ag-cluster-0 2/2 Running 0 2m11s
pod/mssql-ag-cluster-1 2/2 Running 0 2m6s
Let’s verify that the PetSet’s pods have created the availability group cluster successfully,
$ kubectl get secrets -n demo mssql-ag-cluster-auth -o jsonpath='{.data.\username}' | base64 -d
sa
$ kubectl get secrets -n demo mssql-ag-cluster-auth -o jsonpath='{.data.\password}' | base64 -d
123KKxgOXuOkP206
Now, connect to the database using username and password, check the name of the created availability group, replicas of the availability group and see if databases are added to the availability group.
$ kubectl exec -it -n demo mssql-ag-cluster-0 -c mssql -- bash
mssql@mssql-ag-cluster-2:/$ /opt/mssql-tools/bin/sqlcmd -S localhost -U sa -P "123KKxgOXuOkP206"
1> select name from sys.databases
2> go
name
----------------------------------------------------------------------------------
master
tempdb
model
msdb
agdb1
agdb2
kubedb_system
(5 rows affected)
1> SELECT name FROM sys.availability_groups
2> go
name
----------------------------------------------------------------------------
mssqlagcluster
(1 rows affected)
1> select replica_server_name from sys.availability_replicas;
2> go
replica_server_name
-------------------------------------------------------------------------------------------
mssql-ag-cluster-0
mssql-ag-cluster-1
(3 rows affected)
1> select database_name from sys.availability_databases_cluster;
2> go
database_name
------------------------------------------------------------------------------------------
agdb1
agdb2
(2 rows affected)
So, we can see that our cluster has 2 replicas. Now, we are ready to apply the horizontal scale to this MSSQLServer cluster.
Scale Up
Here, we are going to add 1 replica in our Cluster using horizontal scaling.
Create MSSQLServerOpsRequest:
To scale up your cluster, you have to create a MSSQLServerOpsRequest CR with your desired number of replicas after scaling. Below is the YAML of the MSSQLServerOpsRequest CR that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: MSSQLServerOpsRequest
metadata:
name: ms-scale-horizontal
namespace: demo
spec:
type: HorizontalScaling
databaseRef:
name: mssql-ag-cluster
horizontalScaling:
replicas: 3
Here,
spec.databaseRef.namespecifies that we are performing operation onmssql-ag-cluster.spec.typespecifies that we are performingHorizontalScalingon our database.spec.horizontalScaling.replicasspecifies the expected number of replicas after the scaling.
Let’s create the MSSQLServerOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2025.12.9-rc.0/docs/examples/mssqlserver/scaling/horizontal-scaling/msops-hscale-up.yaml
mssqlserveropsrequest.ops.kubedb.com/msops-hscale-up created
Verify Scale-Up Succeeded:
If everything goes well, KubeDB Ops Manager will scale up the PetSet’s Pod. After the scaling process is completed successfully, the KubeDB Ops Manager updates the replicas of the MSSQLServer object.
First, we will wait for MSSQLServerOpsRequest to be successful. Run the following command to watch MSSQLServerOpsRequest cr,
$ watch kubectl get mssqlserveropsrequest -n demo msops-hscale-up
Every 2.0s: kubectl get mssqlserveropsrequest -n demo msops-hscale-up
NAME TYPE STATUS AGE
msops-hscale-up HorizontalScaling Successful 76s
You can see from the above output that the MSSQLServerOpsRequest has succeeded. If we describe the MSSQLServerOpsRequest, we will see that the MSSQLServer cluster is scaled up.
kubectl describe mssqlserveropsrequest -n demo msops-hscale-up
Name: msops-hscale-up
Namespace: demo
Labels: <none>
Annotations: <none>
API Version: ops.kubedb.com/v1alpha1
Kind: MSSQLServerOpsRequest
Metadata:
Creation Timestamp: 2024-10-24T15:09:36Z
Generation: 1
Resource Version: 752963
UID: 43193e49-8461-4e14-b1c1-7aaa33d0251a
Spec:
Apply: IfReady
Database Ref:
Name: mssql-ag-cluster
Horizontal Scaling:
Replicas: 3
Type: HorizontalScaling
Status:
Conditions:
Last Transition Time: 2024-10-24T15:09:36Z
Message: MSSQLServer ops-request has started to horizontally scaling the nodes
Observed Generation: 1
Reason: HorizontalScaling
Status: True
Type: HorizontalScaling
Last Transition Time: 2024-10-24T15:09:39Z
Message: Successfully paused database
Observed Generation: 1
Reason: DatabasePauseSucceeded
Status: True
Type: DatabasePauseSucceeded
Last Transition Time: 2024-10-24T15:10:29Z
Message: Successfully Scaled Up Node
Observed Generation: 1
Reason: HorizontalScaleUp
Status: True
Type: HorizontalScaleUp
Last Transition Time: 2024-10-24T15:09:44Z
Message: get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Observed Generation: 1
Status: True
Type: GetCurrentLeader--mssql-ag-cluster-0
Last Transition Time: 2024-10-24T15:09:44Z
Message: get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0
Observed Generation: 1
Status: True
Type: GetRaftNode--mssql-ag-cluster-0
Last Transition Time: 2024-10-24T15:09:44Z
Message: add raft node; ConditionStatus:True; PodName:mssql-ag-cluster-2
Observed Generation: 1
Status: True
Type: AddRaftNode--mssql-ag-cluster-2
Last Transition Time: 2024-10-24T15:09:49Z
Message: patch petset; ConditionStatus:True; PodName:mssql-ag-cluster-2
Observed Generation: 1
Status: True
Type: PatchPetset--mssql-ag-cluster-2
Last Transition Time: 2024-10-24T15:09:49Z
Message: mssql-ag-cluster already has desired replicas
Observed Generation: 1
Reason: HorizontalScale
Status: True
Type: HorizontalScale
Last Transition Time: 2024-10-24T15:09:59Z
Message: is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2
Observed Generation: 1
Status: True
Type: IsPodReady--mssql-ag-cluster-2
Last Transition Time: 2024-10-24T15:10:19Z
Message: is mssql running; ConditionStatus:True
Observed Generation: 1
Status: True
Type: IsMssqlRunning
Last Transition Time: 2024-10-24T15:10:24Z
Message: ensure replica join; ConditionStatus:True
Observed Generation: 1
Status: True
Type: EnsureReplicaJoin
Last Transition Time: 2024-10-24T15:10:34Z
Message: successfully reconciled the MSSQLServer with modified replicas
Observed Generation: 1
Reason: UpdatePetSets
Status: True
Type: UpdatePetSets
Last Transition Time: 2024-10-24T15:10:35Z
Message: Successfully updated MSSQLServer
Observed Generation: 1
Reason: UpdateDatabase
Status: True
Type: UpdateDatabase
Last Transition Time: 2024-10-24T15:10:35Z
Message: Successfully completed the HorizontalScaling for MSSQLServer
Observed Generation: 1
Reason: Successful
Status: True
Type: Successful
Observed Generation: 1
Phase: Successful
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Starting 2m22s KubeDB Ops-manager Operator Start processing for MSSQLServerOpsRequest: demo/msops-hscale-up
Normal Starting 2m22s KubeDB Ops-manager Operator Pausing MSSQLServer database: demo/mssql-ag-cluster
Normal Successful 2m22s KubeDB Ops-manager Operator Successfully paused MSSQLServer database: demo/mssql-ag-cluster for MSSQLServerOpsRequest: msops-hscale-up
Warning get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 2m14s KubeDB Ops-manager Operator get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0 2m14s KubeDB Ops-manager Operator get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning add raft node; ConditionStatus:True; PodName:mssql-ag-cluster-2 2m14s KubeDB Ops-manager Operator add raft node; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 2m9s KubeDB Ops-manager Operator get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0 2m9s KubeDB Ops-manager Operator get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning patch petset; ConditionStatus:True; PodName:mssql-ag-cluster-2 2m9s KubeDB Ops-manager Operator patch petset; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 2m4s KubeDB Ops-manager Operator get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning is pod ready; ConditionStatus:False; PodName:mssql-ag-cluster-2 2m4s KubeDB Ops-manager Operator is pod ready; ConditionStatus:False; PodName:mssql-ag-cluster-2
Warning get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 119s KubeDB Ops-manager Operator get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2 119s KubeDB Ops-manager Operator is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning is mssql running; ConditionStatus:False 109s KubeDB Ops-manager Operator is mssql running; ConditionStatus:False
Warning get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 109s KubeDB Ops-manager Operator get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2 109s KubeDB Ops-manager Operator is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 99s KubeDB Ops-manager Operator get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2 99s KubeDB Ops-manager Operator is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning is mssql running; ConditionStatus:True 99s KubeDB Ops-manager Operator is mssql running; ConditionStatus:True
Warning ensure replica join; ConditionStatus:False 98s KubeDB Ops-manager Operator ensure replica join; ConditionStatus:False
Warning get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 94s KubeDB Ops-manager Operator get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2 94s KubeDB Ops-manager Operator is pod ready; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning is mssql running; ConditionStatus:True 94s KubeDB Ops-manager Operator is mssql running; ConditionStatus:True
Warning ensure replica join; ConditionStatus:True 94s KubeDB Ops-manager Operator ensure replica join; ConditionStatus:True
Warning get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 89s KubeDB Ops-manager Operator get current leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Normal HorizontalScaleUp 89s KubeDB Ops-manager Operator Successfully Scaled Up Node
Normal UpdatePetSets 84s KubeDB Ops-manager Operator successfully reconciled the MSSQLServer with modified replicas
Normal UpdateDatabase 83s KubeDB Ops-manager Operator Successfully updated MSSQLServer
Normal Starting 83s KubeDB Ops-manager Operator Resuming MSSQLServer database: demo/mssql-ag-cluster
Normal Successful 83s KubeDB Ops-manager Operator Successfully resumed MSSQLServer database: demo/mssql-ag-cluster for MSSQLServerOpsRequest: msops-hscale-up
Normal UpdateDatabase 83s KubeDB Ops-manager Operator Successfully updated MSSQLServer
Now, we are going to verify whether the number of replicas has increased to meet up the desired state. So let’s check the new pods coordinator container’s logs to see if this is joined in the cluster as new replica.
$ kubectl logs -f -n demo mssql-ag-cluster-2 -c mssql-coordinator
raft2024/10/24 15:09:55 INFO: 3 switched to configuration voters=(1 2 3)
raft2024/10/24 15:09:55 INFO: 3 switched to configuration voters=(1 2 3)
raft2024/10/24 15:09:55 INFO: 3 switched to configuration voters=(1 2 3)
raft2024/10/24 15:09:55 INFO: 3 [term: 1] received a MsgHeartbeat message with higher term from 1 [term: 3]
raft2024/10/24 15:09:55 INFO: 3 became follower at term 3
raft2024/10/24 15:09:55 INFO: raft.node: 3 elected leader 1 at term 3
I1024 15:09:56.855261 1 mssql.go:94] new elected primary is :mssql-ag-cluster-0.
I1024 15:09:56.864197 1 mssql.go:120] New primary is ready to accept connections...
I1024 15:09:56.864213 1 mssql.go:171] lastLeaderId : 0, currentLeaderId : 1
I1024 15:09:56.864230 1 on_leader_change.go:47] New Leader elected.
I1024 15:09:56.864237 1 on_leader_change.go:82] This pod is now a secondary according to raft
I1024 15:09:56.864243 1 on_leader_change.go:100] instance demo/mssql-ag-cluster-2 running according to the role
I1024 15:09:56.864317 1 utils.go:219] /scripts/run_signal.txt file created successfully
E1024 15:09:56.935767 1 exec_utils.go:65] Error while trying to get process output from the pod. Error: could not execute: command terminated with exit code 1
I1024 15:09:56.935794 1 on_leader_change.go:110] mssql is not ready yet
I1024 15:10:07.980792 1 on_leader_change.go:110] mssql is not ready yet
I1024 15:10:18.049036 1 on_leader_change.go:110] mssql is not ready yet
I1024 15:10:18.116939 1 on_leader_change.go:118] mssql is ready now
I1024 15:10:18.127315 1 ag_status.go:43] No Availability Group found
I1024 15:10:18.127336 1 ag.go:79] Joining Availability Group...
I1024 15:10:24.638144 1 on_leader_change.go:94] Successfully patched label of demo/mssql-ag-cluster-2 to secondary
I1024 15:10:24.650611 1 health.go:50] Sequence Number updated. new sequenceNumber = 4294967322, previous sequenceNumber = 0
I1024 15:10:24.650632 1 health.go:51] 1:1A (4294967322)
Now, connect to the database, check updated configurations of the availability group cluster.
$ kubectl exec -it -n demo mssql-ag-cluster-2 -c mssql -- bash
mssql@mssql-ag-cluster-2:/$ /opt/mssql-tools/bin/sqlcmd -S localhost -U sa -P "123KKxgOXuOkP206"
1> SELECT name FROM sys.availability_groups
2> go
name
----------------------------------------------------------------------------
mssqlagcluster
(1 rows affected)
1> select replica_server_name from sys.availability_replicas;
2> go
replica_server_name
-------------------------------------------------------------------------------------------
mssql-ag-cluster-0
mssql-ag-cluster-1
mssql-ag-cluster-2
(3 rows affected)
1> select database_name from sys.availability_databases_cluster;
2> go
database_name
------------------------------------------------------------------------------------------
agdb1
agdb2
(2 rows affected)
Scale Down
Here, we are going to remove 1 replica from our cluster using horizontal scaling.
Create MSSQLServerOpsRequest:
To scale down your cluster, you have to create a MSSQLServerOpsRequest CR with your desired number of replicas after scaling. Below is the YAML of the MSSQLServerOpsRequest CR that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: MSSQLServerOpsRequest
metadata:
name: msops-hscale-down
namespace: demo
spec:
type: HorizontalScaling
databaseRef:
name: mssql-ag-cluster
horizontalScaling:
replicas: 2
Let’s create the MSSQLServerOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2025.12.9-rc.0/docs/examples/mssqlserver/scaling/horizontal-scaling/msops-hscale-down.yaml
mssqlserveropsrequest.ops.kubedb.com/msops-hscale-down created
Verify Scale-down Succeeded:
If everything goes well, KubeDB Ops Manager will scale down the PetSet’s Pod. After the scaling process is completed successfully, the KubeDB Ops Manager updates the replicas of the MSSQLServer object.
Now, we will wait for MSSQLServerOpsRequest to be successful. Run the following command to watch MSSQLServerOpsRequest cr,
$ watch kubectl get mssqlserveropsrequest -n demo msops-hscale-down
Every 2.0s: kubectl get mssqlserveropsrequest -n demo msops-hscale-down
NAME TYPE STATUS AGE
msops-hscale-down HorizontalScaling Successful 98s
You can see from the above output that the MSSQLServerOpsRequest has succeeded. If we describe the MSSQLServerOpsRequest, we shall see that the MSSQLServer cluster is scaled down.
$ kubectl describe mssqlserveropsrequest -n demo msops-hscale-down
Name: msops-hscale-down
Namespace: demo
Labels: <none>
Annotations: <none>
API Version: ops.kubedb.com/v1alpha1
Kind: MSSQLServerOpsRequest
Metadata:
Creation Timestamp: 2024-10-24T15:22:54Z
Generation: 1
Resource Version: 754237
UID: c5dc6971-5f60-4736-992a-8fdf5a2911d9
Spec:
Apply: IfReady
Database Ref:
Name: mssql-ag-cluster
Horizontal Scaling:
Replicas: 2
Type: HorizontalScaling
Status:
Conditions:
Last Transition Time: 2024-10-24T15:22:54Z
Message: MSSQLServer ops-request has started to horizontally scaling the nodes
Observed Generation: 1
Reason: HorizontalScaling
Status: True
Type: HorizontalScaling
Last Transition Time: 2024-10-24T15:23:06Z
Message: Successfully paused database
Observed Generation: 1
Reason: DatabasePauseSucceeded
Status: True
Type: DatabasePauseSucceeded
Last Transition Time: 2024-10-24T15:24:06Z
Message: Successfully Scaled Down Node
Observed Generation: 1
Reason: HorizontalScaleDown
Status: True
Type: HorizontalScaleDown
Last Transition Time: 2024-10-24T15:23:21Z
Message: get current raft leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Observed Generation: 1
Status: True
Type: GetCurrentRaftLeader--mssql-ag-cluster-0
Last Transition Time: 2024-10-24T15:23:11Z
Message: get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0
Observed Generation: 1
Status: True
Type: GetRaftNode--mssql-ag-cluster-0
Last Transition Time: 2024-10-24T15:23:11Z
Message: remove raft node; ConditionStatus:True; PodName:mssql-ag-cluster-2
Observed Generation: 1
Status: True
Type: RemoveRaftNode--mssql-ag-cluster-2
Last Transition Time: 2024-10-24T15:23:21Z
Message: patch petset; ConditionStatus:True; PodName:mssql-ag-cluster-2
Observed Generation: 1
Status: True
Type: PatchPetset--mssql-ag-cluster-2
Last Transition Time: 2024-10-24T15:23:21Z
Message: mssql-ag-cluster already has desired replicas
Observed Generation: 1
Reason: HorizontalScale
Status: True
Type: HorizontalScale
Last Transition Time: 2024-10-24T15:23:26Z
Message: get pod; ConditionStatus:False
Observed Generation: 1
Status: False
Type: GetPod
Last Transition Time: 2024-10-24T15:23:56Z
Message: get pod; ConditionStatus:True; PodName:mssql-ag-cluster-2
Observed Generation: 1
Status: True
Type: GetPod--mssql-ag-cluster-2
Last Transition Time: 2024-10-24T15:23:56Z
Message: delete pvc; ConditionStatus:True; PodName:mssql-ag-cluster-2
Observed Generation: 1
Status: True
Type: DeletePvc--mssql-ag-cluster-2
Last Transition Time: 2024-10-24T15:24:01Z
Message: get pvc; ConditionStatus:True
Observed Generation: 1
Status: True
Type: GetPvc
Last Transition Time: 2024-10-24T15:24:01Z
Message: ag node remove; ConditionStatus:True
Observed Generation: 1
Status: True
Type: AgNodeRemove
Last Transition Time: 2024-10-24T15:24:11Z
Message: successfully reconciled the MSSQLServer with modified replicas
Observed Generation: 1
Reason: UpdatePetSets
Status: True
Type: UpdatePetSets
Last Transition Time: 2024-10-24T15:24:11Z
Message: Successfully updated MSSQLServer
Observed Generation: 1
Reason: UpdateDatabase
Status: True
Type: UpdateDatabase
Last Transition Time: 2024-10-24T15:24:11Z
Message: Successfully completed the HorizontalScaling for MSSQLServer
Observed Generation: 1
Reason: Successful
Status: True
Type: Successful
Observed Generation: 1
Phase: Successful
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Starting 2m1s KubeDB Ops-manager Operator Start processing for MSSQLServerOpsRequest: demo/msops-hscale-down
Normal Starting 2m1s KubeDB Ops-manager Operator Pausing MSSQLServer database: demo/mssql-ag-cluster
Normal Successful 2m1s KubeDB Ops-manager Operator Successfully paused MSSQLServer database: demo/mssql-ag-cluster for MSSQLServerOpsRequest: msops-hscale-down
Warning get current raft leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 104s KubeDB Ops-manager Operator get current raft leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0 104s KubeDB Ops-manager Operator get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning remove raft node; ConditionStatus:True; PodName:mssql-ag-cluster-2 104s KubeDB Ops-manager Operator remove raft node; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning get current raft leader; ConditionStatus:True; PodName:mssql-ag-cluster-0 94s KubeDB Ops-manager Operator get current raft leader; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0 94s KubeDB Ops-manager Operator get raft node; ConditionStatus:True; PodName:mssql-ag-cluster-0
Warning patch petset; ConditionStatus:True; PodName:mssql-ag-cluster-2 94s KubeDB Ops-manager Operator patch petset; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning get pod; ConditionStatus:True; PodName:mssql-ag-cluster-2 59s KubeDB Ops-manager Operator get pod; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning delete pvc; ConditionStatus:True; PodName:mssql-ag-cluster-2 59s KubeDB Ops-manager Operator delete pvc; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning get pvc; ConditionStatus:False 59s KubeDB Ops-manager Operator get pvc; ConditionStatus:False
Warning get pod; ConditionStatus:True; PodName:mssql-ag-cluster-2 54s KubeDB Ops-manager Operator get pod; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning delete pvc; ConditionStatus:True; PodName:mssql-ag-cluster-2 54s KubeDB Ops-manager Operator delete pvc; ConditionStatus:True; PodName:mssql-ag-cluster-2
Warning get pvc; ConditionStatus:True 54s KubeDB Ops-manager Operator get pvc; ConditionStatus:True
Warning ag node remove; ConditionStatus:True 54s KubeDB Ops-manager Operator ag node remove; ConditionStatus:True
Normal HorizontalScaleDown 49s KubeDB Ops-manager Operator Successfully Scaled Down Node
Normal UpdatePetSets 44s KubeDB Ops-manager Operator successfully reconciled the MSSQLServer with modified replicas
Normal UpdateDatabase 44s KubeDB Ops-manager Operator Successfully updated MSSQLServer
Normal Starting 44s KubeDB Ops-manager Operator Resuming MSSQLServer database: demo/mssql-ag-cluster
Normal Successful 44s KubeDB Ops-manager Operator Successfully resumed MSSQLServer database: demo/mssql-ag-cluster for MSSQLServerOpsRequest: msops-hscale-down
Normal UpdateDatabase 44s KubeDB Ops-manager Operator Successfully updated MSSQLServer
Now, we are going to verify whether the number of replicas has decreased to meet up the desired state, Let’s check, the mssqlserver status if it’s ready then the scale-down is successful.
$ kubectl get ms,petset,pods -n demo
NAME VERSION STATUS AGE
mssqlserver.kubedb.com/mssql-ag-cluster 2022-cu12 Ready 39m
NAME AGE
petset.apps.k8s.appscode.com/mssql-ag-cluster 38m
NAME READY STATUS RESTARTS AGE
pod/mssql-ag-cluster-0 2/2 Running 0 38m
pod/mssql-ag-cluster-1 2/2 Running 0 38m
Now, connect to the database, check updated configurations of the availability group cluster.
$ kubectl exec -it -n demo mssql-ag-cluster-0 -c mssql -- bash
mssql@mssql-ag-cluster-0:/$ /opt/mssql-tools/bin/sqlcmd -S localhost -U sa -P "123KKxgOXuOkP206"
1> SELECT name FROM sys.availability_groups
2> go
name
----------------------------------------------------
mssqlagcluster
(1 rows affected)
1> select replica_server_name from sys.availability_replicas;
2> go
replica_server_name
--------------------------------------
mssql-ag-cluster-0
mssql-ag-cluster-1
(2 rows affected)
You can see above that our MSSQLServer cluster now has a total of 2 replicas. It verifies that we have successfully scaled down.
Cleaning Up
To clean up the Kubernetes resources created by this tutorial, run:
kubectl delete ms -n demo mssql-ag-cluster
kubectl delete mssqlserveropsrequest -n demo msops-hscale-up
kubectl delete mssqlserveropsrequest -n demo msops-hscale-down
kubectl delete issuer -n demo mssqlserver-ca-issuer
kubectl delete secret -n demo mssqlserver-ca
kubectl delete ns demo