Data persistence is crucial for containerized applications as it ensures that data remains available and consistent even when the application container is stopped, restarted, or migrated to another host. Containerized applications are designed to be ephemeral, meaning they can be created, destroyed, and recreated as needed. However, the data generated and used by these applications should be persistent to maintain application functionality and data integrity.
To achieve data persistence in containerized applications, Docker provides the concept of volumes. Volumes are a way to persist data generated by and used by Docker containers. They are a separate entity managed by Docker and can be used to store data that needs to be shared between containers or between a container and the host system. Volumes provide a decoupled storage layer that can be managed independently of the container’s lifecycle.
Here are some possible options for implementing data persistence using Docker volumes:
- Named volumes: Named volumes are volumes that have a name and can be managed using Docker commands. They are created and managed by Docker and are not tied to a specific container. Named volumes can be used to share data between containers or between a container and the host system. Here’s an example of creating a named volume:
docker volume create my-volume
- Host volumes: Host volumes are volumes that are created on the host system and mounted into a container. Host volumes can be used to share data between a container and the host system. Here’s an example of creating a host volume:
docker run -v /path/on/host:/path/in/container my-image
- Anonymous volumes: Anonymous volumes are volumes that are automatically created when a container is started with the
-vflag and no volume name is specified. Anonymous volumes are managed by Docker and are not named or easily managed. Here’s an example of creating an anonymous volume:
docker run -v /path/in/container my-image
- ** Third-party plugins**: Docker also supports third-party plugins that can be used to provide additional volume management functionality. These plugins can provide features such as networked storage, encryption, and backup.
For more information, refer to the following resources:
- Using the Java Persistence API (JPA) to connect Java to various data persistence solutions
- Persistent storage in action: Understanding Red Hat OpenShift’s persistent volume framework
- MongoDB vs PostgreSQL: What to consider when choosing a database
- Scalable data classification for security, privacy - Engineering at Meta
- Databases Checkpoint
- Stateful Workloads Overview | Nomad | HashiCorp Developer
- Practical data engineering concepts and skills
- How Quarkus simplifies Java persistence | Red Hat Developer
