DBaaS architecture¶
DBaaS is built on top of PMM and Kubernetes and the high-level architecture is shown below
In DBaaS, the role of PMM is as follows:
- Expose Public REST API
- Provision Kubernetes cluster and install the following operators:
- OLM (Operator Lifecycle Manager)
- Percona Operator for MongoDB
- Percona Operator for MySQL
- DBaaS operator
Operator Lifecycle Manager (OLM)¶
DBaaS uses OLM to install and update operators. PMM installs OLM and Operator Catalog during the registration of the Kubernetes cluster.
An Operator catalog is a repository of metadata that Operator Lifecycle Manager (OLM) can query to discover and install Operators and their dependencies on a cluster. OLM always installs Operators from the latest version of a catalog and if a new version of an operator becomes available, OLM can upgrade it once the user has accepted the upgrade. DBaaS uses its own catalog for OLM that has the following operators:
- DBaaS operator
- PXC operator
- PSMDB operator
- Victoria Metrics operator
Percona Catalog is an OLM catalog that stores ClusterServiceVersions and CustomResourceDefinitions for creation in a cluster, and stores metadata about packages and channels. It’s a source of truth for the available versions of operators ready to use in DBaaS
The installation of operators looks the following way
DBaaS operator¶
DBaaS operator is responsible for creating and managing databases following operator pattern and depends on underlying operators for running database clusters. It provides a simplified API to manage database clusters via kubectl.