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Using Custom Configuration File
KubeDB supports providing custom configuration for SingleStore. This tutorial will show you how to use KubeDB to run a SingleStore database with custom configuration.
Before You Begin
At first, 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.
To keep things isolated, this tutorial uses a separate namespace called
demothroughout this tutorial.$ kubectl create ns demo namespace/demo created $ kubectl get ns demo NAME STATUS AGE demo Active 5s
Note: YAML files used in this tutorial are stored in docs/guides/singlestore/configuration/config-file/yamls folder in GitHub repository kubedb/docs.
Overview
SingleStore allows to configure database via configuration file. The default configuration for SingleStore can be found in /var/lib/memsql/instance/memsql.cnf file. When SingleStore starts, it will look for custom configuration file in /etc/memsql/conf.d directory. If configuration file exist, SingleStore instance will use combined startup setting from both /var/lib/memsql/instance/memsql.cnf and *.cnf files in /etc/memsql/conf.d directory. This custom configuration will overwrite the existing default one. To know more about configuring SingleStore see here.
At first, you have to create a config file with .cnf extension with your desired configuration. Then you have to put this file into a volume. You need to specify this volume in the spec.configSecret section when creating the SingleStore CRD for Standalone mode. Additionally, you can modify your aggregator and leaf nodes separately by providing separate configSecrets, or use the same one in the spec.topology.aggregator.configSecret and spec.topology.leaf.configSecret sections when creating the SingleStore CRD for Cluster mode. KubeDB will mount this volume into /etc/memsql/conf.d directory of the database pod.
In this tutorial, we will configure max_connections and read_buffer_size via a custom config file. We will use configMap as volume source.
Create SingleStore License Secret
We need SingleStore License to create SingleStore Database. So, Ensure that you have acquired a license and then simply pass the license by secret.
$ kubectl create secret generic -n demo license-secret \
--from-literal=username=license \
--from-literal=password='your-license-set-here'
secret/license-secret created
Custom Configuration
At first, let’s create sdb-config.cnf file setting max_connections and read_buffer_size parameters.
cat <<EOF > sdb-config.cnf
[server]
max_connections = 250
read_buffer_size = 1048576
EOF
$ cat sdb-config.cnf
[server]
max_connections = 250
read_buffer_size = 122880
Now, create a secret with this configuration file.
$ kubectl create secret generic -n demo sdb-configuration --from-file=./sdb-config.cnf
configmap/sdb-configuration created
Verify the secret has the configuration file.
$ kubectl get secret -n demo sdb-configuration -o yaml
apiVersion: v1
data:
sdb-config.cnf: W3NlcnZlcl0KbWF4X2Nvbm5lY3Rpb25zID0gMjUwCnJlYWRfYnVmZmVyX3NpemUgPSAxMjI4ODAK
kind: Secret
metadata:
creationTimestamp: "2024-10-02T12:54:35Z"
name: sdb-configuration
namespace: demo
resourceVersion: "99627"
uid: c2621d8e-ebca-4300-af05-0180512ce031
type: Opaque
Now, create SingleStore crd specifying spec.topology.aggregator.configSecret and spec.topology.leaf.configSecret field.
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.9.30/docs/guides/singlestore/configuration/config-file/yamls/sdb-custom.yaml
singlestore.kubedb.com/custom-sdb created
Below is the YAML for the SingleStore crd we just created.
apiVersion: kubedb.com/v1alpha2
kind: Singlestore
metadata:
name: custom-sdb
namespace: demo
spec:
version: "8.7.10"
topology:
aggregator:
replicas: 2
configSecret:
name: sdb-configuration
podTemplate:
spec:
containers:
- name: singlestore
resources:
limits:
memory: "2Gi"
cpu: "600m"
requests:
memory: "2Gi"
cpu: "600m"
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
leaf:
replicas: 2
configSecret:
name: sdb-configuration
podTemplate:
spec:
containers:
- name: singlestore
resources:
limits:
memory: "2Gi"
cpu: "600m"
requests:
memory: "2Gi"
cpu: "600m"
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 10Gi
licenseSecret:
name: license-secret
storageType: Durable
deletionPolicy: WipeOut
Now, wait a few minutes. KubeDB operator will create necessary PVC, petset, services, secret etc.
Check that the petset’s pod is running
$ kubectl get pod -n demo
NAME READY STATUS RESTARTS AGE
custom-sdb-aggregator-0 2/2 Running 0 94s
custom-sdb-aggregator-1 2/2 Running 0 88s
custom-sdb-leaf-0 2/2 Running 0 91s
custom-sdb-leaf-1 2/2 Running 0 86s
$ kubectl get sdb -n demo
NAME TYPE VERSION STATUS AGE
custom-sdb kubedb.com/v1alpha2 8.7.10 Ready 4m29s
We can see the database is in ready phase so it can accept conncetion.
Now, we will check if the database has started with the custom configuration we have provided.
Read the comment written for the following commands. They contain the instructions and explanations of the commands.
# Connceting to the database
$ kubectl exec -it -n demo custom-sdb-aggregator-0 -- bash
Defaulted container "singlestore" out of: singlestore, singlestore-coordinator, singlestore-init (init)
[memsql@custom-sdb-aggregator-0 /]$ memsql -uroot -p$ROOT_PASSWORD
singlestore-client: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 208
Server version: 5.7.32 SingleStoreDB source distribution (compatible; MySQL Enterprise & MySQL Commercial)
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
# value of `max_conncetions` is same as provided
singlestore> show variables like 'max_connections';
+-----------------+-------+
| Variable_name | Value |
+-----------------+-------+
| max_connections | 250 |
+-----------------+-------+
1 row in set (0.00 sec)
# value of `read_buffer_size` is same as provided
singlestore> show variables like 'read_buffer_size';
+------------------+--------+
| Variable_name | Value |
+------------------+--------+
| read_buffer_size | 122880 |
+------------------+--------+
1 row in set (0.00 sec)
singlestore> exit
Bye
Cleaning up
To cleanup the Kubernetes resources created by this tutorial, run:
kubectl patch -n demo my/custom-sdb -p '{"spec":{"deletionPolicy":"WipeOut"}}' --type="merge"
kubectl delete -n demo my/custom-sdb
kubectl delete ns demo
If you would like to uninstall KubeDB operator, please follow the steps here.
Next Steps
- Quickstart SingleStore with KubeDB Operator.
- Detail concepts of singlestore object.
- Want to hack on KubeDB? Check our contribution guidelines.