Managed database service like RDS

    MYSQL is most ubiquitous and commonly used database. RDS is a service that make deploying and making MYSQL easy. With OpenEBS CAS architecture each user is assigned an independent stack of storage that serves just one instance of MySQL database, making it easy to handle the provisioning and post deployment operations like capacity increase and upgrades.

    Use OpenEBS and MySQL containers to quickly launch an RDS like service, where database launch is instantaneous, availability is provided across zones and increase in requested capacity can happen on the fly.

    Deployment model

    As shown above, OpenEBS volumes need to be configured with three replicas for high availability. This configuration work fine when the nodes (hence the cStor pool) is deployed across Kubernetes zones.

    2. Configure cStor Pool : After OpenEBS installation, cStor pool has to be configured. As MySQL is a deployment, it need high availability at storage level. OpenEBS cStor volume has to be configured with 3 replica. During cStor Pool creation, make sure that the maxPools parameter is set to >=3. If cStor Pool is already configured as required go to Step 4 to create MySQL StorageClass.

    3. Create Storage Class

      You must configure a StorageClass to provision cStor volume on cStor pool. StorageClass is the interface through which most of the OpenEBS storage policies are defined. In this solution we are using a StorageClass to consume the cStor Pool which is created using external disks attached on the Nodes. Since MySQL is a deployments, it requires high availability of data at storage level. So cStor volume is 3. Sample YAML named openebs-sc-disk.yamlto consume cStor pool with cStorVolume Replica count as 3 is provided in the configuration details below.

    4. Launch and test Mysql:

      Run MySQL database application using the stable helm chart. The following command will install MySQL database application in your cluster. This command will create a PVC of size 8Gi for running the database.

      For more information about installation, see MySQL .

    Post deployment Operations

    It is not seamless to increase the cStor volume size (refer to the roadmap item). Hence, it is recommended that sufficient size is allocated during the initial configuration. However, an alert can be setup for volume size threshold using Kubera.

    Monitor cStor Pool size

    As in most cases, cStor pool may not be dedicated to just MySQL alone. It is recommended to watch the pool capacity and add more disks to the pool before it hits 80% threshold. See

    Maintain volume replica quorum during node upgrades

    cStor volume replicas need to be in quorum when MySQL application is deployed as and cStor volume is configured to have . Node reboots may be common during Kubernetes upgrade. Maintain volume replica quorum in such instances. See here for more details.

    openebs-config.yaml

    See Also: