Using the MySQL Kubernetes Operator makes deploying and managing stateful applications in Kubernetes easier. It automates deployment and supports features such as backup, scaling, and recovery, including high availability through replicating Pods hosting MySQL Cluster instances.
It leverages Kubernetes Custom Resource Definitions to automatically create Deployments, Services, ConfigMaps, and Persistent Volume Claims for the application. It also offers several features for database management, such as replication lag mitigation and scheduled backups to external object storage.
Scalability
Kubernetes offers a highly flexible platform for deploying and managing cloud-native apps. Its architecture allows scalable, highly available services through a Unified Abstraction Layer. It also supports using unified tools and processes across public and private clouds. However, database deployments require specific and different considerations.
With this in mind, scalability is one of the key benefits of using the MySQL Kubernetes Operator. The MySQL operator enables users to deploy and manage a MySQL cluster within the Kubernetes environment easily. This is a result of the fact that it is designed to support the entire database lifecycle, including upgrades and scheduled backups.
This is achieved by combining a custom resource definition and the Kubernetes features known as Persistent Volume Claims, which allow storage to be apportioned to individual pods. Furthermore, the Operator uses a process called “slow query log,” which keeps track of slow queries and is helpful for troubleshooting purposes.
The Operator aims to ensure the proper configuration of the MySQL cluster by continuously monitoring the state of the database. This is done through a loop, in which the Operator compares the desired state of the MySQL Cluster with its current state and makes changes accordingly. The Operator then applies those changes to the MySQL Cluster and, if necessary, repeats the loop until the desired state is achieved.
Backups
The MySQL Operator for Kubernetes enables you to manage a stateful MySQL InnoDB Cluster using Kubernetes primitives. It automates and simplifies deployment procedures to integrate into DevOps workflows easily. It also provides high availability through the replication of Pods hosting your database and automated self-healing in case of failure.
However, while replication offers a high level of fault tolerance, it can not guard against data loss caused by hardware failures or accidental deletions. To mitigate this risk, adequate backups are critical to any database deployment.
While several solutions exist for backing up databases, they typically require separate tools and impose complex workflows on the application deployment. Moreover, they often require elevated security privileges to quiesce file systems for backups or otherwise make the system unavailable.
With the MySQL Kubernetes Operator, you can leverage a simple backup process that doesn’t affect the availability of your database deployment. The kubectl create job command can take a backup on your chosen schedule. The backup profile can be defined in the backup profiles specification object, or values can be specified individually for each backup request.
The resulting backup can be stored in any Kubernetes storage class, but the best option is to store it in an S3-compatible object storage. The backupPolicy resource allows you to specify a ServiceAccount that is privileged to access the object storage bucket and set environment variables to pass necessary credentials.
Security
While Kubernetes is great for stateless applications, handling a database workload can take much work. Pods for database clusters are constantly being destroyed and re-created, which introduces the possibility of lost data or application interruptions. This isn’t ideal for databases, which must remain up at all times.
The MySQL Kubernetes Operator makes managing database instances on K8s easier by enabling you to use the same declarative configuration format used for stateless apps. It also handles deployment, scaling, and backups of your database instance. It can be installed on the Kubernetes platform using Helm or by creating an image with a Kubernetes command line interface.
Once an Operator is installed, it watches for changes to custom resources and performs any necessary actions. For example, if a Deployment is modified to run more memory for a database, the Operator will create more instances to accommodate the additional load. It will also update the database’s PersistentVolumeClaim to use more storage if needed.
By lowering the amount of read and write operations on the central database, the MySQL Operator can also enhance performance. The Operator also provides improved scalability and high availability by managing the replication of the database. This is possible because it uses raft for persistent disks distributed across the cluster.
Monitoring
Managing stateful applications such as databases is complex and challenging to manage through Kubernetes alone. But using the operator pattern, you can automate and streamline these tasks by encoding domain-specific knowledge into software operators. This allows you to scale, maintain high availability, and integrate with monitoring systems.
Unlike traditional deployments, operators enable you to provision your application’s objects based on a custom configuration. This eliminates the need for manual updates and makes it easier to deploy new apps. It also helps you manage the entire lifecycle of your app, including upgrades and backups.
Oracle offers an official MySQL Operator for Kubernetes, which enables you to deploy and manage InnoDB Cluster instances on your Kubernetes cluster. It uses a persistent storage class called Persistent Volume Claims to store data. It also provides multi-data center support, network discovery, and routing features. The MySQL operator manages the database’s network security and supports various data formats.
Other providers of MySQL Operators for Kubernetes include Bitpoke, GrdsCloud, and Percona Server. Each solution has its unique functionality and benefits. Some come prepackaged as Helm charts, which significantly shortens the deployment process. For example, Bitpoke’s MySQL Operator is easy to install and manage and provides a declarative configuration format. Its asynchronous sync loops prevent error propagation, making it fast and dependable. In addition, it allows you to back up, restore, scale, and upgrade your MySQL instances.
