Overview
KubeDB is the Kubernetes Native Database Management Solution which simplifies and automates routine database tasks such as Provisioning, Monitoring, Upgrading, Patching, Scaling, Volume Expansion, Backup, Recovery, Failure detection, and Repair for various popular databases on private and public clouds. The databases supported by KubeDB include MongoDB, Elasticsearch, MySQL, MariaDB, Redis, PostgreSQL, FerretDB, Percona XtraDB, and Memcached. Additionally, KubeDB also supports ProxySQL, PgBouncer and the streaming platform Kafka. You can find the guides to all the supported databases in KubeDB . In this tutorial we will show Vertical scaling of PostgreSQL cluster in Google Kubernetes Engine (GKE). We will cover the following steps:
- Install KubeDB
- Deploy PostgreSQL Cluster
- Read/Write Sample Data
- Vertical Scaling of PostgreSQL Cluster
Get Cluster ID
We need the cluster ID to get the KubeDB License. To get cluster ID, we can run the following command:
$ kubectl get ns kube-system -o jsonpath='{.metadata.uid}'
8e336615-0dbb-4ae8-b72f-2e7ec34c399d
Get License
Go to Appscode License Server to get the license.txt file. For this tutorial we will use KubeDB.
Install KubeDB
We will use helm to install KubeDB. Please install helm here
if it is not already installed.
Now, let’s install KubeDB.
$ helm search repo appscode/kubedb
NAME CHART VERSION APP VERSION DESCRIPTION
appscode/kubedb v2024.3.16 v2024.3.16 KubeDB by AppsCode - Production ready databases...
appscode/kubedb-autoscaler v0.29.0 v0.29.1 KubeDB Autoscaler by AppsCode - Autoscale KubeD...
appscode/kubedb-catalog v2024.3.16 v2024.3.16 KubeDB Catalog by AppsCode - Catalog for databa...
appscode/kubedb-community v0.24.2 v0.24.2 KubeDB Community by AppsCode - Community featur...
appscode/kubedb-crd-manager v0.0.8 v0.0.8 KubeDB CRD Manager by AppsCode
appscode/kubedb-crds v2024.3.16 v2024.3.16 KubeDB Custom Resource Definitions
appscode/kubedb-dashboard v0.20.0 v0.20.0 KubeDB Dashboard by AppsCode
appscode/kubedb-enterprise v0.11.2 v0.11.2 KubeDB Enterprise by AppsCode - Enterprise feat...
appscode/kubedb-grafana-dashboards v2024.3.16 v2024.3.16 A Helm chart for kubedb-grafana-dashboards by A...
appscode/kubedb-kubestash-catalog v2024.3.16 v2024.3.16 KubeStash Catalog by AppsCode - Catalog of Kube...
appscode/kubedb-metrics v2024.3.16 v2024.3.16 KubeDB State Metrics
appscode/kubedb-one v2023.12.28 v2023.12.28 KubeDB and Stash by AppsCode - Production ready...
appscode/kubedb-ops-manager v0.31.0 v0.31.0 KubeDB Ops Manager by AppsCode - Enterprise fea...
appscode/kubedb-opscenter v2024.3.16 v2024.3.16 KubeDB Opscenter by AppsCode
appscode/kubedb-provider-aws v2024.3.16 v0.6.0 A Helm chart for KubeDB AWS Provider for Crossp...
appscode/kubedb-provider-azure v2024.3.16 v0.6.0 A Helm chart for KubeDB Azure Provider for Cros...
appscode/kubedb-provider-gcp v2024.3.16 v0.6.0 A Helm chart for KubeDB GCP Provider for Crossp...
appscode/kubedb-provisioner v0.44.0 v0.44.1 KubeDB Provisioner by AppsCode - Community feat...
appscode/kubedb-schema-manager v0.20.0 v0.20.0 KubeDB Schema Manager by AppsCode
appscode/kubedb-ui v2024.4.2 0.6.5 A Helm chart for Kubernetes
appscode/kubedb-ui-server v2021.12.21 v2021.12.21 A Helm chart for kubedb-ui-server by AppsCode
appscode/kubedb-webhook-server v0.20.0 v0.20.0 KubeDB Webhook Server by AppsCode
$ helm install kubedb oci://ghcr.io/appscode-charts/kubedb \
--version v2024.3.16 \
--namespace kubedb --create-namespace \
--set-file global.license=/path/to/the/license.txt \
--wait --burst-limit=10000 --debug
Let’s verify the installation:
$ kubectl get pods --all-namespaces -l "app.kubernetes.io/instance=kubedb"
NAMESPACE NAME READY STATUS RESTARTS AGE
kubedb kubedb-kubedb-autoscaler-777bc6b47d-66f9f 1/1 Running 0 4m52s
kubedb kubedb-kubedb-ops-manager-8655d7fd94-cvwgm 1/1 Running 0 4m52s
kubedb kubedb-kubedb-provisioner-6868bbff85-wlbjf 1/1 Running 0 4m52s
kubedb kubedb-kubedb-webhook-server-848d6fb7b7-hr59l 1/1 Running 0 4m52s
kubedb kubedb-petset-operator-5d94b4ddb8-9gwf9 1/1 Running 0 4m52s
kubedb kubedb-petset-webhook-server-78d78bc87-5hx2f 2/2 Running 0 4m52s
kubedb kubedb-sidekick-5dc87959b7-khh5r 1/1 Running 0 4m52s
We can list the CRD Groups that have been registered by the operator by running the following command:
$ kubectl get crd -l app.kubernetes.io/name=kubedb
NAME CREATED AT
connectclusters.kafka.kubedb.com 2024-04-22T03:45:17Z
connectors.kafka.kubedb.com 2024-04-22T03:45:17Z
druidversions.catalog.kubedb.com 2024-04-22T03:44:34Z
elasticsearchautoscalers.autoscaling.kubedb.com 2024-04-22T03:45:14Z
elasticsearchdashboards.elasticsearch.kubedb.com 2024-04-22T03:45:14Z
elasticsearches.kubedb.com 2024-04-22T03:45:14Z
elasticsearchopsrequests.ops.kubedb.com 2024-04-22T03:45:14Z
elasticsearchversions.catalog.kubedb.com 2024-04-22T03:44:34Z
etcdversions.catalog.kubedb.com 2024-04-22T03:44:34Z
ferretdbversions.catalog.kubedb.com 2024-04-22T03:44:34Z
kafkaautoscalers.autoscaling.kubedb.com 2024-04-22T03:45:17Z
kafkaconnectorversions.catalog.kubedb.com 2024-04-22T03:44:34Z
kafkaopsrequests.ops.kubedb.com 2024-04-22T03:45:17Z
kafkas.kubedb.com 2024-04-22T03:45:17Z
kafkaversions.catalog.kubedb.com 2024-04-22T03:44:34Z
mariadbarchivers.archiver.kubedb.com 2024-04-22T03:45:21Z
mariadbautoscalers.autoscaling.kubedb.com 2024-04-22T03:45:21Z
mariadbdatabases.schema.kubedb.com 2024-04-22T03:45:21Z
mariadbopsrequests.ops.kubedb.com 2024-04-22T03:45:21Z
mariadbs.kubedb.com 2024-04-22T03:45:21Z
mariadbversions.catalog.kubedb.com 2024-04-22T03:44:34Z
memcachedversions.catalog.kubedb.com 2024-04-22T03:44:34Z
mongodbarchivers.archiver.kubedb.com 2024-04-22T03:45:25Z
mongodbautoscalers.autoscaling.kubedb.com 2024-04-22T03:45:24Z
mongodbdatabases.schema.kubedb.com 2024-04-22T03:45:25Z
mongodbopsrequests.ops.kubedb.com 2024-04-22T03:45:24Z
mongodbs.kubedb.com 2024-04-22T03:45:24Z
mongodbversions.catalog.kubedb.com 2024-04-22T03:44:34Z
mysqlarchivers.archiver.kubedb.com 2024-04-22T03:45:28Z
mysqlautoscalers.autoscaling.kubedb.com 2024-04-22T03:45:28Z
mysqldatabases.schema.kubedb.com 2024-04-22T03:45:28Z
mysqlopsrequests.ops.kubedb.com 2024-04-22T03:45:28Z
mysqls.kubedb.com 2024-04-22T03:45:28Z
mysqlversions.catalog.kubedb.com 2024-04-22T03:44:34Z
perconaxtradbversions.catalog.kubedb.com 2024-04-22T03:44:34Z
pgbouncerversions.catalog.kubedb.com 2024-04-22T03:44:34Z
pgpoolversions.catalog.kubedb.com 2024-04-22T03:44:34Z
postgresarchivers.archiver.kubedb.com 2024-04-22T03:45:32Z
postgresautoscalers.autoscaling.kubedb.com 2024-04-22T03:45:32Z
postgresdatabases.schema.kubedb.com 2024-04-22T03:45:32Z
postgreses.kubedb.com 2024-04-22T03:45:32Z
postgresopsrequests.ops.kubedb.com 2024-04-22T03:45:32Z
postgresversions.catalog.kubedb.com 2024-04-22T03:44:34Z
proxysqlversions.catalog.kubedb.com 2024-04-22T03:44:34Z
publishers.postgres.kubedb.com 2024-04-22T03:45:32Z
rabbitmqversions.catalog.kubedb.com 2024-04-22T03:44:34Z
redisautoscalers.autoscaling.kubedb.com 2024-04-22T03:45:35Z
redises.kubedb.com 2024-04-22T03:45:35Z
redisopsrequests.ops.kubedb.com 2024-04-22T03:45:35Z
redissentinelautoscalers.autoscaling.kubedb.com 2024-04-22T03:45:35Z
redissentinelopsrequests.ops.kubedb.com 2024-04-22T03:45:35Z
redissentinels.kubedb.com 2024-04-22T03:45:35Z
redisversions.catalog.kubedb.com 2024-04-22T03:44:34Z
singlestoreversions.catalog.kubedb.com 2024-04-22T03:44:34Z
solrversions.catalog.kubedb.com 2024-04-22T03:44:34Z
subscribers.postgres.kubedb.com 2024-04-22T03:45:32Z
zookeeperversions.catalog.kubedb.com 2024-04-22T03:44:34Z
Deploy PostgreSQL Cluster
We are going to Deploy PostgreSQL Cluster by using KubeDB. First, let’s create a Namespace in which we will deploy the database.
$ kubectl create namespace demo
namespace/demo created
Here is the yaml of the PostgreSQL CRO we are going to use:
apiVersion: kubedb.com/v1alpha2
kind: Postgres
metadata:
name: postgres-cluster
namespace: demo
spec:
version: "16.1"
replicas: 3
standbyMode: Hot
storageType: Durable
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
terminationPolicy: WipeOut
Let’s save this yaml configuration into postgres-cluster.yaml
Then create the above PostgreSQL CRO
$ kubectl apply -f postgres-cluster.yaml
postgres.kubedb.com/postgres-cluster created
In this yaml,
- In this yaml we can see in the
spec.versionfield specifies the version of PostgreSQL. Here, we are using PostgreSQLversion 16.1. You can list the KubeDB supported versions of PostgreSQL by runningkubectl get postgresversionscommand. spec.standbyis an optional field that specifies the standby modehotorwarmto use for standby replicas. Inhotstandby mode, standby replicas can accept connection and run read-only queries. Inwarmstandby mode, standby replicas can’t accept connection and only used for replication purpose.spec.storage.storageClassNameis the name of the StorageClass used to provision PVCs.spec.terminationPolicyfield is Wipeout means that the database will be deleted without restrictions. It can also be “Halt”, “Delete” and “DoNotTerminate”. Learn More about these checkout Termination Policy .
Once these are handled correctly and the PostgreSQL object is deployed, you will see that the following objects are created:
$ kubectl get all -n demo
NAME READY STATUS RESTARTS AGE
pod/postgres-cluster-0 2/2 Running 0 2m15s
pod/postgres-cluster-1 2/2 Running 0 90s
pod/postgres-cluster-2 2/2 Running 0 83s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/postgres-cluster ClusterIP 10.96.10.43 <none> 5432/TCP,2379/TCP 2m19s
service/postgres-cluster-pods ClusterIP None <none> 5432/TCP,2380/TCP,2379/TCP 2m19s
service/postgres-cluster-standby ClusterIP 10.96.84.21 <none> 5432/TCP 2m19s
NAME READY AGE
statefulset.apps/postgres-cluster 3/3 2m15s
NAME TYPE VERSION AGE
appbinding.appcatalog.appscode.com/postgres-cluster kubedb.com/postgres 16.1 2m15s
NAME VERSION STATUS AGE
postgres.kubedb.com/postgres-cluster 16.1 Ready 2m19s
Let’s check if the database is ready to use,
$ kubectl get pg -n demo postgres-cluster
NAME VERSION STATUS AGE
postgres-cluster 16.1 Ready 2m39s
We have successfully deployed PostgreSQL cluster in GKE. Now we can exec into the container to use the database.
Accessing Database Through CLI
To access the database through CLI, we have to get the credentials to access. KubeDB will create Secret and Service for the database postgres-cluster that we have deployed. Let’s check them using the following commands,
$ kubectl get secret -n demo -l=app.kubernetes.io/instance=postgres-cluster
NAME TYPE DATA AGE
postgres-cluster-auth kubernetes.io/basic-auth 2 2m56s
$ kubectl get service -n demo -l=app.kubernetes.io/instance=postgres-cluster
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
postgres-cluster ClusterIP 10.96.10.43 <none> 5432/TCP,2379/TCP 3m15s
postgres-cluster-pods ClusterIP None <none> 5432/TCP,2380/TCP,2379/TCP 3m15s
postgres-cluster-standby ClusterIP 10.96.84.21 <none> 5432/TCP 3m15s
Now, we are going to use postgres-cluster-auth to get the credentials.
$ kubectl get secrets -n demo postgres-cluster-auth -o jsonpath='{.data.username}' | base64 -d
postgres
$ kubectl get secrets -n demo postgres-cluster-auth -o jsonpath='{.data.password}' | base64 -d
9E6YsUhCwYldZT8t
Insert Sample Data
In this section, we are going to login into our PostgreSQL pod and insert some sample data.
$ kubectl exec -it postgres-cluster-0 -n demo -c postgres -- bash
postgres-cluster-0:/$ psql -d "user=postgres password=9E6YsUhCwYldZT8t"
psql (16.1)
Type "help" for help.
postgres=# \l
List of databases
Name | Owner | Encoding | Locale Provider | Collate | Ctype | ICU Locale | ICU Rules | Access privileges
---------------+----------+----------+-----------------+------------+------------+------------+-----------+-----------------------
kubedb_system | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | |
postgres | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | |
template0 | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | | =c/postgres +
| | | | | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | | =c/postgres +
| | | | | | | | postgres=CTc/postgres
(4 rows)
postgres=# CREATE DATABASE music;
CREATE DATABASE
postgres=# \l
List of databases
Name | Owner | Encoding | Locale Provider | Collate | Ctype | ICU Locale | ICU Rules | Access privileges
---------------+----------+----------+-----------------+------------+------------+------------+-----------+-----------------------
kubedb_system | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | |
music | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | |
postgres | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | |
template0 | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | | =c/postgres +
| | | | | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | | =c/postgres +
| | | | | | | | postgres=CTc/postgres
(5 rows)
postgres=# CREATE TABLE artist (name VARCHAR(50) NOT NULL, song VARCHAR(50) NOT NULL);
CREATE TABLE
postgres=# INSERT INTO artist (name, song) VALUES('John Denver', 'Country Roads');
INSERT 0 1
postgres=# SELECT * FROM artist;
name | song
-------------+---------------
John Denver | Country Roads
(1 row)
postgres=# \q
postgres-cluster-0:/$ exit
exit
We’ve successfully inserted some sample data to our database. More information about Run & Manage PostgreSQL on Kubernetes can be found in PostgreSQL Kubernetes
Vertical Scaling of PostgreSQL Cluster
We are going to scale up the current cpu resource of the PostgreSQL cluster by applying Vertical Scaling. Before applying it, let’s check the current resources,
$ kubectl get pod -n demo postgres-cluster-0 -o json | jq '.spec.containers[].resources'
{
"limits": {
"memory": "1Gi"
},
"requests": {
"cpu": "500m",
"memory": "1Gi"
}
}
{
"limits": {
"memory": "256Mi"
},
"requests": {
"cpu": "200m",
"memory": "256Mi"
}
}
Vertical Scale Up
Create PostgresOpsRequest
In order to update the resources of the cluster, we have to create a PostgresOpsRequest CR with our desired resources. Let’s create it using this following yaml,
apiVersion: ops.kubedb.com/v1alpha1
kind: PostgresOpsRequest
metadata:
name: vertical-scale-up
namespace: demo
spec:
type: VerticalScaling
databaseRef:
name: postgres-cluster
verticalScaling:
postgres:
resources:
requests:
memory: "1100Mi"
cpu: "0.55"
limits:
memory: "1100Mi"
cpu: "0.55"
In this yaml,
spec.databaseRef.namespecifies that we are performing vertical scaling operation onpostgres-clusterdatabase.spec.typespecifies that we are performingVerticalScalingon our database.spec.verticalScaling.resourcesspecifies the desired resources after scaling.
Let’s save this yaml configuration into vertical-scale-up.yaml and apply it,
$ kubectl apply -f vertical-scale-up.yaml
postgresopsrequest.ops.kubedb.com/vertical-scale-up created
Let’s wait for PostgresOpsRequest STATUS to be Successful. Run the following command to watch PostgresOpsRequest CR,
$ watch kubectl get postgresopsrequest -n demo
NAME TYPE STATUS AGE
vertical-scale-up VerticalScaling Successful 115s
We can see from the above output that the PostgresOpsRequest has succeeded. Now, we are going to verify from one of the Pod yaml whether the resources of the database has updated to meet up the desired state. Let’s check with the following command,
$ kubectl get pod -n demo postgres-cluster-0 -o json | jq '.spec.containers[].resources'
{
"limits": {
"cpu": "550m",
"memory": "1100Mi"
},
"requests": {
"cpu": "550m",
"memory": "1100Mi"
}
}
{
"limits": {
"memory": "256Mi"
},
"requests": {
"cpu": "200m",
"memory": "256Mi"
}
}
The above output verifies that we have successfully scaled up the resources of the PostgreSQL cluster.
Vertical Scale Down
Create PostgresOpsRequest
In order to update the resources of the database, we have to create a PostgresOpsRequest CR with our desired resources. Let’s create it using this following yaml,
apiVersion: ops.kubedb.com/v1alpha1
kind: PostgresOpsRequest
metadata:
name: vertical-scale-down
namespace: demo
spec:
type: VerticalScaling
databaseRef:
name: postgres-cluster
verticalScaling:
postgres:
resources:
requests:
memory: "1Gi"
cpu: "0.5"
limits:
memory: "1Gi"
cpu: "0.5"
In this yaml,
spec.databaseRef.namespecifies that we are performing vertical scaling operation onpostgres-clusterdatabase.spec.typespecifies that we are performingVerticalScalingon our database.spec.verticalScaling.resourcesspecifies the desired resources after scaling.
Let’s save this yaml configuration into vertical-scale-down.yaml and apply it,
$ kubectl apply -f vertical-scale-down.yaml
postgresopsrequest.ops.kubedb.com/vertical-scale-down created
Let’s wait for PostgresOpsRequest STATUS to be Successful. Run the following command to watch PostgresOpsRequest CR,
$ watch kubectl get postgresopsrequest -n demo
NAME TYPE STATUS AGE
vertical-scale-down VerticalScaling Successful 2m5s
We can see from the above output that the PostgresOpsRequest has succeeded. Now, we are going to verify from one of the Pod yaml whether the resources of the database has updated to meet up the desired state. Let’s check with the following command,
$ kubectl get pod -n demo postgres-cluster-0 -o json | jq '.spec.containers[].resources'
{
"limits": {
"cpu": "500m",
"memory": "1Gi"
},
"requests": {
"cpu": "500m",
"memory": "1Gi"
}
}
{
"limits": {
"memory": "256Mi"
},
"requests": {
"cpu": "200m",
"memory": "256Mi"
}
}
The above output verifies that we have successfully scaled down the resources of the PostgreSQL cluster.
If you want to learn more about Production-Grade PostgreSQL you can have a look into that playlist below:
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Learn more about PostgreSQL on Kubernetes
If you have found a bug with KubeDB or want to request for new features, please file an issue .