Plan for Confluent Platform Deployment¶
This topic contains the supported and recommended options to consider when you plan to deploy Confluent Platform using Confluent for Kubernetes (CFK).
At the high level, the workflow to configure, deploy, and manage Confluent Platform using CFK is as follows:
Review this topic and review the required and recommended options for the deployment environment.
Prepare your Kubernetes environment.
For details, see Prepare Kubernetes Cluster for Confluent Platform.
Deploy Confluent for Kubernetes.
For details, see Deploy Confluent for Kubernetes.
Configure Confluent Platform.
For details, see Configure Confluent Platform.
Deploy Confluent Platform.
For details, see Deploy Confluent Platform.
Manage Confluent Platform.
For details, see Manage Confluent Platform with Confluent for Kubernetes.
The following is a deployment checklist to prepare for a Confluent Platform deployment:
Supported environments and prerequisites¶
Review and address the following prerequisites before you start the installation process.
Confluent for Kubernetes 2.0.0 supports Kubernetes versions 1.15 to 1.20 with any Cloud Native Computing Foundation (CNCF) conformant offering. A full list of CNCF conformant Kubernetes offerings can be found here.
The following API must be present in your Kubernetes:
To check for the API, run the following command. The output should include
kubectl api-versions | grep apiextensions.k8s.io
Configure the kubeconfig file for your cluster.
If you are using Red Hat OpenShift as your Kubernetes distribution, you need to determine how you work with Red Hat’s Security Context Constraint (SCC). See this documentation set to understand how.
The underlying Operating System (OS) of your Kubernetes worker nodes must be a supported version for the Confluent Platform version you plan to deploy.
See Supported Versions and Interoperability for supported OSs for a specific version of Confluent Platform.
Review the sizing guidelines and recommendations in this section before creating your Confluent cluster.
The following table provides the guidance on the minimum cluster sizing:
|ZooKeeper||4||14 GB||100 GB||2||8 GB||100 GB|
|Kafka Brokers||12||24 GB||12 TB||4||16 GB||1 TB|
|Connect Workers||12||24 GB||500 GB||4||16 GB||100 GB|
|Schema Registry||2||4 GB||100 GB||2||4 GB||50 GB|
|Confluent Control Center||12||24 GB||500 GB||4||16 GB||250 GB|
Note that ZooKeeper and Kafka must be installed on separate, individual pods on separate nodes.
At least three Kafka brokers are required for a fully functioning Confluent Platform deployment. A one- or two-broker configuration is not supported and should not be used for development, testing, or production.
The number of Kubernetes worker nodes required in your cluster depends on whether you are deploying a development testing cluster or a production-ready cluster.
- Production Cluster
Review the default capacity values in the Confluent Platform component custom resources (CRs). Determine how these values affect your production application and build out your nodes accordingly.
You can also use the on-premises System Requirements to determine what is required for your cloud production environment. Note that the on-premises storage information provided is not applicable for cloud environments.
- Development Testing Cluster
Each node should typically have a minimum of 2 or 4 CPUs and 7 to 16 GB RAM. If you are testing a deployment of CFK and all Confluent Platform components, you can create a 10-node cluster with six nodes for Apache ZooKeeper™ and Apache Kafka® pods (three replicas each) and four nodes for all other components pods.
Confluent recommends running ZooKeeper and Kafka on separate pods on separate Kubernetes nodes.
For further details on sizing recommendations, see Sizing Calculator for Apache Kafka and Confluent Platform.
Confluent for Kubernetes pulls Confluent Docker images from a Docker registry and deploys those on to your Kubernetes cluster.
By default, Confluent for Kubernetes deploys publicly-available Docker images hosted on Docker
Hub from the
If you choose to use your own Docker registry and repositories, you need to pull the images from the Confluent repositories and upload to your Docker registry repositories.
See Use Custom Docker Registry for Confluent Platform for details on using custom private registry.
You need to provide dynamic persistent storage for all Confluent Platform components with block-level storage solutions, such as AWS EBS, Azure Disk, GCE Disk, Ceph RBD, and Portworx.
See Configure Storage for Confluent Platform for details on storage configuration options.
With Kubernetes Role-based access control (RBAC) and namespaces, you can deploy Confluent Platform in one of two ways:
- (Recommended) Provide Confluent for Kubernetes with access to provision and manage Confluent Platform resources in one specific namespace.
- Provide Confluent for Kubernetes with access to provision and manage Confluent Platform resources across all namespaces in the Kubernetes cluster.
Both options above require Kubernetes role bindings configuration. See Configure Kubernetes RBAC and Custom Resource Definitions for details.
Confluent supports the following processes to enforce security.
- Network encryption
- Configuration secrets
For production deployments, Confluent recommends the following security mechanisms:
Enable one of the following methods for Kafka client authentication:
For SASL/Plain, the identity can come from your LDAP server.
Enable Confluent Role Based Access Control (RBAC) for authorization, with user/group identity coming from the LDAP server.
Enable TLS for network encryption for both internal traffic between Confluent Platform components and external traffic from clients to Confluent Platform components.
See Production recommended secure setup for a tutorial scenario to configure these security settings.
Confluent Platform components can be accessed by users and client applications that are either:
- In the internal Kubernetes network
- External to the Kubernetes network
The following are the options to externally expose Confluent Platform:
- Load balancers
- For Kafka, a Layer 4 load balancer that supports TLS passthrough is required.
- For other Confluent components with HTTP endpoints, a Layer 4/7 load balancer is required.
- Kubernetes node ports
- Static external access with host-based or port-based routing
- OpenShift routes
Default ports in Confluent for Kubernetes¶
CFK uses the following default ports for Confluent Platform components. You can override the default ports in the component custom resources.
- JMX port: 7203
- Jolokia port: 7777
- Prometheus port: 7778
- Kafka External port: 9092
- Kafka Internal port: 9071
- Replication port: 9072
- Token port: 9073
- MDS default port: 8090
- Control Center default listener port: 9021
- Control Center HTTP port: 8021
- Schema Registry default external listener port: 8081
- Schema Registry internal listener port: 9081
- ksqlDB external port: 8088
- ksqlDB internal port: 9088
- Connect external port: 8083
- Connect internal port: 9083
Upgrades and updates¶
CFK provides a declarative API and configuration automation for running Confluent Platform on Kubernetes. You can update configurations and upgrade versions for an existing deployment by applying the updated declarative specs in custom resource files.
However, the following are configuration scenarios that cannot be enabled or changed for an existing deployment:
- Confluent RBAC. You cannot enable Confluent RBAC on an existing cluster.
- TLS certificates mechanism. You cannot change the mechanism for how TLS certificates are provided between auto-generated certificates and user provided certificates.
- TLS encryption. You cannot enable TLS encryption on a TLS disabled cluster.
- Kafka listener authentication. You cannot change the authentication mechanism used for an existing Kafka listener.
- External network access mechanism for Kafka brokers. You cannot change the external network access mechanism for Kafka brokers among load balancer, node ports, static ingress controller based routing.
- Storage class for persistent storage. You cannot change the storage class used to create Persistent Volume Claims for Confluent components.
- Configuration secrets mechanism. You cannot change the configuration secrets mechanism between using Kubernetes secrets and directory in path containers.