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Add autoscaling guide
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Signed-off-by: Neaj Morshad <[email protected]>
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Neaj-Morshad-101 committed Oct 28, 2024
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113 changes: 64 additions & 49 deletions docs/guides/mssqlserver/autoscaler/storage/cluster.md
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Expand Up @@ -159,21 +159,21 @@ Now, wait until `mssqlserver-ag-cluster` has status `Ready`. i.e,

```bash
$ kubectl get mssqlserver -n demo
NAME VERSION STATUS AGE
mssqlserver-ag-cluster 16.1 Ready 3m46s
NAME VERSION STATUS AGE
mssqlserver-ag-cluster 2022-cu12 Ready 89m
```

Let's check volume size from petset, and from the persistent volume,

```bash
$ kubectl get sts -n demo mssqlserver-ag-cluster -o json | jq '.spec.volumeClaimTemplates[].spec.resources.requests.storage'
$ kubectl get petset -n demo mssqlserver-ag-cluster -o json | jq '.spec.volumeClaimTemplates[].spec.resources.requests.storage'
"1Gi"
$ kubectl get pv -n demo
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-43266d76-f280-4cca-bd78-d13660a84db9 1Gi RWO Delete Bound demo/data-mssqlserver-ag-cluster-2 topolvm-provisioner 57s
pvc-4a509b05-774b-42d9-b36d-599c9056af37 1Gi RWO Delete Bound demo/data-mssqlserver-ag-cluster-0 topolvm-provisioner 58s
pvc-c27eee12-cd86-4410-b39e-b1dd735fc14d 1Gi RWO Delete Bound demo/data-mssqlserver-ag-cluster-1 topolvm-provisioner 57s
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS VOLUMEATTRIBUTESCLASS REASON AGE
pvc-1497dd6d-9cbd-467a-8e0c-c3963ce09e1b 1Gi RWO Delete Bound demo/data-mssqlserver-ag-cluster-1 longhorn <unset> 88m
pvc-37a7bc8d-2c04-4eb4-8e53-e610fd1daaf5 1Gi RWO Delete Bound demo/data-mssqlserver-ag-cluster-0 longhorn <unset> 88m
pvc-817866af-5277-4d51-8d81-434e8ec1c442 1Gi RWO Delete Bound demo/data-mssqlserver-ag-cluster-2 longhorn <unset> 88m
```

You can see the petset has 1GB storage, and the capacity of all the persistent volume is also 1GB.
Expand All @@ -186,38 +186,38 @@ Here, we are going to set up storage autoscaling using a `MSSQLServerAutoscaler`

#### Create MSSQLServerAutoscaler Object

In order to set up vertical autoscaling for this cluster database, we have to create a `MSSQLServerAutoscaler` CRO with our desired configuration. Below is the YAML of the `MSSQLServerAutoscaler` object that we are going to create,
In order to set up storage autoscaling for this database cluster, we have to create a `MSSQLServerAutoscaler` CRO with our desired configuration. Below is the YAML of the `MSSQLServerAutoscaler` object that we are going to create,

```yaml
apiVersion: autoscaling.kubedb.com/v1alpha1
kind: MSSQLServerAutoscaler
metadata:
name: ms-as-st
name: ms-as-storage
namespace: demo
spec:
databaseRef:
name: mssqlserver-ag-cluster
storage:
mssqlserver:
trigger: "On"
usageThreshold: 20
scalingThreshold: 20
expansionMode: "Online"
usageThreshold: 60
scalingThreshold: 50
expansionMode: "Offline"
```

Here,

- `spec.databaseRef.name` specifies that we are performing vertical scaling operation on `mssqlserver-ag-cluster` database.
- `spec.databaseRef.name` specifies that we are performing volume expansion operation on `mssqlserver-ag-cluster` database.
- `spec.storage.mssqlserver.trigger` specifies that storage autoscaling is enabled for this database.
- `spec.storage.mssqlserver.usageThreshold` specifies storage usage threshold, if storage usage exceeds `20%` then storage autoscaling will be triggered.
- `spec.storage.mssqlserver.scalingThreshold` specifies the scaling threshold. Storage will be scaled to `20%` of the current amount.
- `spec.storage.mssqlserver.expansionMode` specifies the expansion mode of volume expansion `MSSQLServerOpsRequest` created by `MSSQLServerAutoscaler`. topolvm-provisioner supports online volume expansion so here `expansionMode` is set as "Online".
- `spec.storage.mssqlserver.usageThreshold` specifies storage usage threshold, if storage usage exceeds `60%` then storage autoscaling will be triggered.
- `spec.storage.mssqlserver.scalingThreshold` specifies the scaling threshold. Storage will be scaled to `50%` of the current amount.
- `spec.storage.mssqlserver.expansionMode` specifies the expansion mode of volume expansion `MSSQLServerOpsRequest` created by `MSSQLServerAutoscaler`, `longhorn` supports offline volume expansion so here `expansionMode` is set as "Offline".

Let's create the `MSSQLServerAutoscaler` CR we have shown above,

```bash
$ kubectl apply -f https://github.com/kubedb/docs/raw/{{< param "info.version" >}}/docs/examples/mssqlserver/autoscaler/storage/msas-storage.yaml
mssqlserverautoscaler.autoscaling.kubedb.com/ms-as-st created
$ kubectl apply -f https://github.com/kubedb/docs/raw/{{< param "info.version" >}}/docs/examples/mssqlserver/autoscaler/storage/ms-as-storage.yaml
mssqlserverautoscaler.autoscaling.kubedb.com/ms-as-storage created
```

#### Storage Autoscaling is set up successfully
Expand All @@ -226,59 +226,72 @@ Let's check that the `mssqlserverautoscaler` resource is created successfully,

```bash
$ kubectl get mssqlserverautoscaler -n demo
NAME AGE
ms-as-st 33s
NAME AGE
ms-as-storage 17s
$ kubectl describe mssqlserverautoscaler ms-as-st -n demo
Name: ms-as-st
$ kubectl describe mssqlserverautoscaler ms-as-storage -n demo
Name: ms-as-storage
Namespace: demo
Labels: <none>
Annotations: API Version: autoscaling.kubedb.com/v1alpha1
Annotations: <none>
API Version: autoscaling.kubedb.com/v1alpha1
Kind: MSSQLServerAutoscaler
Metadata:
Creation Timestamp: 2022-01-14T06:08:02Z
Creation Timestamp: 2024-10-28T12:27:31Z
Generation: 1
Managed Fields:
...
Resource Version: 24009
UID: 4f45a3b3-fc72-4d04-b52c-a770944311f6
Resource Version: 494502
UID: 834cf122-b68c-41a5-924f-8b7fc09f4ed5
Spec:
Database Ref:
Name: mssqlserver-ag-cluster
Storage:
Mariadb:
Scaling Threshold: 20
Mssqlserver:
Expansion Mode: Offline
Scaling Threshold: 50
Trigger: On
Usage Threshold: 20
Usage Threshold: 60
Events: <none>
```

So, the `mssqlserverautoscaler` resource is created successfully.

Now, for this demo, we are going to manually fill up the persistent volume to exceed the `usageThreshold` using `dd` command to see if storage autoscaling is working or not.
Now, for this demo, we are going to manually fill up the persistent volume to exceed the `usageThreshold` using `dd` command to see storage autoscaling.

Let's exec into the database pod and fill the database volume(`/var/pv/data`) using the following commands:
Lets exec into the database pod and fill the database volume(`/var/opt/mssql/`) using the following commands:

```bash
$ kubectl exec -it -n demo mssqlserver-ag-cluster-0 -- bash
root@mssqlserver-ag-cluster-0:/ df -h /var/pv/data
Filesystem Size Used Avail Use% Mounted on
/dev/topolvm/57cd4330-784f-42c1-bf8e-e743241df164 1014M 357M 658M 36% /var/pv/data
root@mssqlserver-ag-cluster-0:/ dd if=/dev/zero of=/var/pv/data/file.img bs=500M count=1
1+0 records in
1+0 records out
524288000 bytes (524 MB, 500 MiB) copied, 0.340877 s, 1.5 GB/s
root@mssqlserver-ag-cluster-0:/ df -h /var/pv/data
Filesystem Size Used Avail Use% Mounted on
/dev/topolvm/57cd4330-784f-42c1-bf8e-e743241df164 1014M 857M 158M 85% /var/pv/data
$ kubectl exec -it -n demo mssqlserver-ag-cluster-0 -c mssql -- bash
mssql@mssqlserver-ag-cluster-0:/$ df -h /var/opt/mssql
Filesystem Size Used Avail Use% Mounted on
/dev/longhorn/pvc-37a7bc8d-2c04-4eb4-8e53-e610fd1daaf5 974M 274M 685M 29% /var/opt/mssql
mssql@mssqlserver-ag-cluster-0:/$ dd if=/dev/zero of=/var/opt/mssql/file.img bs=120M count=5
5+0 records in
5+0 records out
629145600 bytes (629 MB, 600 MiB) copied, 6.09315 s, 103 MB/s
mssql@mssqlserver-ag-cluster-0:/$ df -h /var/opt/mssql
Filesystem Size Used Avail Use% Mounted on
/dev/longhorn/pvc-37a7bc8d-2c04-4eb4-8e53-e610fd1daaf5 974M 874M 85M 92% /var/opt/mssql
```

So, from the above output we can see that the storage usage is 83%, which exceeded the `usageThreshold` 20%.
So, from the above output we can see that the storage usage is 92%, which exceeded the `usageThreshold` 60%.

Let's watch the `mssqlserveropsrequest` in the demo namespace to see if any `mssqlserveropsrequest` object is created. After some time you'll see that a `mssqlserveropsrequest` of type `VolumeExpansion` will be created based on the `scalingThreshold`.












```bash
$ kubectl get mssqlserveropsrequest -n demo
$ watch kubectl get mssqlserveropsrequest -n demo
NAME TYPE STATUS AGE
msops-mssqlserver-ag-cluster-xojkua VolumeExpansion Progressing 15s
```
Expand Down Expand Up @@ -313,7 +326,7 @@ Metadata:
Block Owner Deletion: true
Controller: true
Kind: MSSQLServerAutoscaler
Name: ms-as-st
Name: ms-as-storage
UID: 4f45a3b3-fc72-4d04-b52c-a770944311f6
Resource Version: 25557
UID: 90763a49-a03f-407c-a233-fb20c4ab57d7
Expand Down Expand Up @@ -359,7 +372,7 @@ Events:
Normal Successful 103s KubeDB Enterprise Operator Controller has Successfully expand the volume of MSSQLServer: demo/mssqlserver-ag-cluster
```

Now, we are going to verify from the `Petset`, and the `Persistent Volume` whether the volume of the cluster database has expanded to meet the desired state, Let's check,
Now, we are going to verify from the `Petset`, and the `Persistent Volumes` whether the volume of the database has expanded to meet the desired state, Let's check,

```bash
$ kubectl get sts -n demo mssqlserver-ag-cluster -o json | jq '.spec.volumeClaimTemplates[].spec.resources.requests.storage'
Expand All @@ -379,6 +392,8 @@ To clean up the Kubernetes resources created by this tutorial, run:

```bash
kubectl delete mssqlserver -n demo mssqlserver-ag-cluster
kubectl delete mssqlserverautoscaler -n demo ms-as-st
kubectl delete mssqlserverautoscaler -n demo ms-as-storage
kubectl delete issuer -n demo mssqlserver-ca-issuer
kubectl delete secret -n demo mssqlserver-ca
kubectl delete ns demo
```

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