# KUDO Kafka Concepts
KUDO Kafka is a Kubernetes operator built on top of KUDO (opens new window) and requires KUDO
# KUDO Kafka CRDs
There are three CRDs that are installed when deploying KUDO Kafka:
- Operator: the definition that describes the Kudo Kafka operator.
- OperatorVersion: the definition that describes the Kudo Kafka operator for a specific version.
- Instance: the instantiation of a KUDO Kafka cluster based on the OperatorVersion.
# KUDO Controller Reconcile Cycle
The KUDO controller continually watches the Operator, OperatorVersion and Instance CRDs via the Kubernetes API.
When a user installs KUDO Kafka using the kudo-cli
, the controller creates the KUDO Kafka CRDs for Operator, OperatorVersion and Instance. More information can be read in KUDO Architecture (opens new window)
When the KUDO Controller detects a new Instance
, it creates all the resources required to reach the desired state of the configuration.
The same process is followed for any updates or deletions. Everything is handled by the KUDO Controller.