Strimzi Overview

This guide serves as an introduction to Strimzi, outlining key Kafka concepts that are central to operating Strimzi. It briefly explains Kafka’s components, their purposes, and configuration points, including security and monitoring options. Strimzi provides the necessary files to deploy and manage a Kafka cluster, along with example configuration files for monitoring your deployment.

Strimzi enables the deployment of Apache Kafka components to a Kubernetes cluster, typically running as clusters for high availability.

A standard Kafka deployment using Strimzi might include the following components:

Not all of these components are required, though you need Kafka as a minimum for a Strimzi-managed Kafka cluster. Depending on your use case, you can deploy the additional components as needed. These components can also be used with Kafka clusters that are not managed by Strimzi.

Apache Kafka is an open-source distributed publish-subscribe messaging system for fault-tolerant real-time data feeds.

For more information about Apache Kafka, see the Apache Kafka documentation.

Kafka Connect uses a plugin architecture to provide the implementation artifacts for connectors. Plugins allow connections to other systems and provide additional configuration to manipulate data. Plugins include connectors and other components, such as data converters and transforms. A connector operates with a specific type of external system. Each connector defines a schema for its configuration. You supply the configuration to Kafka Connect to create a connector instance within Kafka Connect. Connector instances then define a set of tasks for moving data between systems.

Plugins provide a set of one or more artifacts that define a connector and task implementation for connecting to a given kind of data source. The configuration describes the source input data and target output data to feed into and out of Kafka Connect. The plugins might also contain the libraries and files needed to transform the data.

A Kafka Connect deployment can have one or more plugins, but only one version of each plugin. Plugins for many external systems are available for use with Kafka Connect. You can also create your own plugins.

Strimzi operates Kafka Connect in distributed mode, distributing data streaming tasks across one or more worker pods. A Kafka Connect cluster comprises a group of worker pods. Each connector is instantiated on a single worker. Each connector comprises one or more tasks that are distributed across the group of workers. Distribution across workers permits highly scalable pipelines.

Workers convert data from one format into another format that’s suitable for the source or target system. Depending on the configuration of the connector instance, workers might also apply transforms (also known as Single Message Transforms, or SMTs). Transforms adjust messages, such as filtering certain data, before they are converted. Kafka Connect has some built-in transforms, but other transformations can be provided by plugins if necessary.

The API has two main resources — consumers and topics — that are exposed and made accessible through endpoints to interact with consumers and producers in your Kafka cluster. The resources relate only to the Kafka Bridge, not the consumers and producers connected directly to Kafka.

Strimzi operators support tasks related to a Kafka deployment. Strimzi custom resources provide the deployment configuration. This includes configuration for Kafka clusters, topics, users, and other components. Leveraging custom resource configuration, Strimzi operators create, configure, and manage Kafka components within a Kubernetes environment. Using operators reduces the need for manual intervention and streamlines the process of managing Kafka in a Kubernetes cluster.

Strimzi provides the following operators for managing a Kafka cluster running within a Kubernetes cluster.

The Cluster Operator can deploy the Topic Operator and User Operator as part of an Entity Operator configuration at the same time as a Kafka cluster.

Use custom resources to configure the following components:

Strimzi provides example configuration files, which can serve as a starting point when building your own Kafka component configuration for deployment.

For detailed configuration instructions and examples, see the guide for Deploying and Managing Strimzi.

Metrics data is useful when investigating issues with connectivity and data delivery. For example, metrics data can identify under-replicated partitions or the rate at which messages are consumed. Alerting rules can provide time-critical notifications on such metrics through a specified communications channel. Monitoring visualizations present real-time metrics data to help determine when and how to update the configuration of your deployment. Example metrics configuration files are provided with Strimzi.

You can employ the following tools for metrics and monitoring: