documentation
Get Started Free
  • Get Started Free
  • Stream
      Confluent Cloud

      Fully-managed data streaming platform with a cloud-native Kafka engine (KORA) for elastic scaling, with enterprise security, stream processing, governance.

      Confluent Platform

      An on-premises enterprise-grade distribution of Apache Kafka with enterprise security, stream processing, governance.

  • Connect
      Managed

      Use fully-managed connectors with Confluent Cloud to connect to data sources and sinks.

      Self-Managed

      Use self-managed connectors with Confluent Platform to connect to data sources and sinks.

  • Govern
      Managed

      Use fully-managed Schema Registry and Stream Governance with Confluent Cloud.

      Self-Managed

      Use self-managed Schema Registry and Stream Governance with Confluent Platform.

  • Process
      Managed

      Use Flink on Confluent Cloud to run complex, stateful, low-latency streaming applications.

      Self-Managed

      Use Flink on Confluent Platform to run complex, stateful, low-latency streaming applications.

Stream
Confluent Cloud

Fully-managed data streaming platform with a cloud-native Kafka engine (KORA) for elastic scaling, with enterprise security, stream processing, governance.

Confluent Platform

An on-premises enterprise-grade distribution of Apache Kafka with enterprise security, stream processing, governance.

Connect
Managed

Use fully-managed connectors with Confluent Cloud to connect to data sources and sinks.

Self-Managed

Use self-managed connectors with Confluent Platform to connect to data sources and sinks.

Govern
Managed

Use fully-managed Schema Registry and Stream Governance with Confluent Cloud.

Self-Managed

Use self-managed Schema Registry and Stream Governance with Confluent Platform.

Process
Managed

Use Flink on Confluent Cloud to run complex, stateful, low-latency streaming applications.

Self-Managed

Use Flink on Confluent Platform to run complex, stateful, low-latency streaming applications.

Learn
Get Started Free
  1. Home
  2. Platform
  3. Multi-DC Deployment Architectures
  4. Cluster Linking
  5. Cluster Linking

CONFLUENT PLATFORM

  • Overview
  • Get Started
    • What is Confluent Platform?
    • Quick Start for Confluent Platform
    • Kafka Basics on Confluent Platform
    • Apache Kafka Introduction
    • Videos, Demos, and Reading Material
      • Scripted Confluent Platform Demo
        • Overview
        • Deploy Confluent Platform Environment
        • Deploy Hybrid Confluent Platform and Cloud Environment
        • End Demo
        • Troubleshooting
      • Tutorial: Introduction to Streaming Application Development
      • Clickstream Data Analysis Pipeline Using ksqlDB
      • RBAC Example for Confluent Platform
      • Replicator Schema Translation Example for Confluent Platform
      • DevOps for Kafka with Kubernetes and GitOps
        • Overview
        • Kafka DevOps Case Studies
          • Case Study: Graduated Environments
          • Case Study: Manage Cloud Secrets
          • Case Study: Kafka Connect management with GitOps
    • Resources
  • Install and Upgrade
    • Overview
    • System Requirements
    • Install Manually
      • ZIP and TAR
      • Ubuntu and Debian
      • RHEL and CentOS
      • Docker
        • Install using Docker
        • Docker Configuration Parameters
        • Docker Image Reference
        • Docker Security
        • Docker Developer Guide
      • Configure Automatic Startup and Monitoring
    • Deploy with Ansible Playbooks
    • Deploy with Confluent for Kubernetes
    • License
    • Upgrade Confluent Platform
      • Overview
      • Upgrade Confluent Platform
    • Supported Versions and Interoperability
    • Installation Packages
    • Migrate from Apache Kafka
    • Migrate an Existing Kafka Deployment
    • Migrate to Confluent Server
    • Migrate from ZooKeeper to KRaft (EA)
  • Build Client Applications
    • Overview
    • Configure Clients
      • Consumer
      • Producer
      • Schemas, Serializers, and Deserializers
      • Configuration Properties
    • Client Guides
      • Python
      • .NET Client
      • JavaScript Client
      • Go Client
      • C++ Client
      • Java Client
      • JMS Client
        • Overview
        • Development Guide
    • Client Examples
      • Overview
      • Python Client
      • .NET Client
      • JavaScript Client
      • Go Client
      • C++ Client
      • Java
      • Spring Boot
      • KafkaProducer
      • REST
      • Clojure
      • Groovy
      • Kafka Connect Datagen
      • kafkacat
      • Kotlin
      • Ruby
      • Rust
      • Scala
    • Kafka Client APIs
      • Python Client API
      • .NET Client API
      • JavaScript Client API
      • Go Client API
      • C++ Client API
      • Java Client API
      • JMS Client
        • Overview
        • Development Guide
    • Deprecated Client APIs
    • MQTT Proxy
      • Introduction
      • Communication Security Settings
      • MQTT Proxy Configuration Options
    • kcat (formerly kafkacat) Utility
  • Confluent REST Proxy
    • Overview
    • Quick Start
    • Rest Proxy API Reference
    • Production Deployment
      • Confluent Server Admin APIs
        • Configuration
        • Security
      • Standalone REST Proxy
        • Overview
        • Configuration
        • Monitoring
        • Security
    • REST Proxy Tutorial
    • Connect to Confluent Cloud
  • ksqlDB and Kafka Streams
    • Overview
    • ksqlDB
      • ksqlDB Overview
      • ksqlDB Quickstart
      • Install ksqlDB
      • Operate ksqlDB
      • Upgrade ksqlDB
      • Develop applications for ksqlDB
      • Run ksqlDB in Confluent Cloud
      • Connect ksqlDB to Confluent Cloud
      • Migrate Confluent Cloud ksqlDB applications
      • Run ksqlDB in Confluent Control Center
      • Connect ksqlDB to Confluent Control Center
      • Secure ksqlDB with RBAC
      • Frequently Asked Questions
      • Troubleshoot ksqlDB issues
      • Tutorials and Examples
        • Tutorials overview
        • ksqlDB Quick Start
        • How-to Guides
        • Example Code Snippets
        • Materialized View/cache
        • Streaming ETL Pipeline
        • Event-driven Microservice
        • ksqlDB with Embedded Connect
        • Clickstream Data Analysis Pipeline Using ksqlDB
        • Kafka Tutorials Using ksqlDB
    • Kafka Streams
      • Kafka Streams Overview
      • Introduction
      • Build your first Streams application
      • Tutorial: Introduction to Streaming Application Development
      • Connect Confluent Platform Components to Confluent Cloud
      • Streams Concepts
      • Streams Architecture
      • Streams Code Examples
      • Streams Developer Guide
        • Writing a Streams Application
        • Testing Streams Code
        • Configuring a Streams Application
        • Streams DSL
        • Naming Kafka Streams DSL Topologies
        • Optimizing Kafka Streams Topologies
        • Processor API
        • Data Types and Serialization
        • Interactive Queries
        • Memory Management
        • Running Streams Applications
        • Managing Streams Application Topics
        • Kafka Streams Security
        • Application Reset Tool
      • Pipelining with Kafka Connect and Kafka Streams
      • Streams Operations
        • Capacity Planning and Sizing
        • Monitoring Kafka Streams Applications
      • Streams Upgrade Guide
      • Streams FAQ
      • Streams Javadocs
  • Connect to External Systems
    • Overview
    • Get Started
    • Kafka Connect 101
    • Connectors
    • Confluent Hub
      • Overview
      • Confluent Hub Client
      • Command Reference
        • Overview
        • confluent-hub help
        • confluent-hub install
      • Component Archive Specification
      • Contribute to Confluent Hub
    • Connect on z/OS
    • Install
    • License
    • Supported
    • Preview
    • Configure
    • Monitor
    • Logging
    • Connect to Confluent Cloud
    • Developer Guide
    • Tutorial: Moving Data In and Out of Kafka
    • Reference
      • Connect Javadocs
      • Connect REST Interface
      • Worker Configuration Properties
      • Connector Configuration Properties
    • Transform
    • Security
      • Kafka Connect Security Basics
      • Kafka Connect and RBAC
        • Get Started With RBAC and Kafka Connect
        • Configure RBAC for a Connect Cluster
        • Configure RBAC for a Connect Worker
        • RBAC for self-managed connectors
        • Connect Secret Registry
        • Example Connect role-binding sequence
    • Design
    • Add Connectors and Software
    • Install Community Connectors
    • Upgrade
    • FileStream Connectors
    • FAQ
  • Schema Management
    • Overview
    • Tutorial
    • Installing and Configuring
      • Install
      • Configure Schema Registry
      • Configure Clients to Schema Registry
      • Deploy in Production
      • Deployment Architectures
      • Migrate Schemas
    • Fundamentals
      • Key Concepts
      • Schema Evolution and Compatibility for Schema Registry on Confluent Platform
      • Schema Formats for Schema Registry on Confluent Platform
        • Serializers and Deserializers Overview
        • Avro
        • Protobuf
        • JSON Schema
      • Data Contracts
    • Manage Schemas
      • Manage Schemas in Control Center
      • Schema Contexts
      • Schema Linking
      • Schema Validation
      • Monitoring
      • Delete Schemas
      • Integrate Schemas from Connectors
    • Security
      • Schema Registry Security Overview
      • Role-Based Access Control
      • Schema Registry Security Plugin
        • Overview
        • Install and Configure
        • Schema Registry Authorization
          • Supported Operations and Resources
          • Role-Based Access Control
          • Schema Registry ACL Authorizer
          • Topic ACL Authorizer
    • Reference
      • Overview
      • Maven Plugin
      • API Reference
      • API Usage Examples
    • FAQ
  • Security
    • General Security
      • Security Overview
      • Security Tutorial
      • Configuring Confluent Server Authorizer
      • Cluster Registry
      • Security Compliance
      • Prefixes for Configuring Security
    • Authentication
      • Authentication Methods Overview
      • Authentication with SASL
        • Authentication with SASL using JAAS
        • Install
        • Configuring GSSAPI
        • Configuring OAUTHBEARER
        • Configuring PLAIN
        • Configuring SCRAM
        • Authentication using Delegation Tokens
        • Configuring Kafka Client Authentication with LDAP
      • Encrypt and Authenticate with TLS
      • HTTP Basic Authentication
      • Adding security to a running cluster
    • Authorization
      • Authorization using Role-Based Access Control
        • RBAC Overview
        • Quick Start
        • Predefined Roles
        • Enable RBAC in a Running Cluster
        • Discover Identifiers for Clusters
        • Configuring Token Authentication
        • Confluent Metadata API Reference
        • RBAC Example for Confluent Platform
      • Configure RBAC using the REST API
      • ACLs
        • Authorization using centralized ACLs
        • Authorization using Access Control Lists (ACLs)
      • Group-Based Authorization Using LDAP
        • Configuring Confluent Server Authorizer
        • Configuring LDAP
        • Tutorial: Group-Based Authorization Using LDAP
    • Data Protection
      • Audit Logs
        • Audit Log Concepts
        • Auditable Events
        • Configure Audit Logs using the Confluent CLI
        • Configure MDS to Manage Centralized Audit Logs
        • MDS API Audit Log Configuration
        • Configure Audit Logs using the Properties File
      • Encrypt with TLS
      • Secrets
        • Secrets Management
        • Tutorial: Secret Protection
      • Redact Confluent Logs
    • Component Security
      • Confluent Control Center (Legacy) Security
        • Overview
        • Configure TLS/SSL
        • Configure SASL
        • Configure HTTP Basic Authentication
        • Authorize with Kafka ACLs
        • Configure LDAP
        • Configure RBAC
        • Manage and View RBAC Roles
          • Log in to Control Center (Legacy) when RBAC enabled
          • Manage RBAC roles with Control Center (Legacy)
          • View your RBAC roles in Control Center (Legacy)
      • Kafka Streams Security
      • Schema Registry Security
      • Kafka Connect Security
        • Kafka Connect Security Basics
        • Kafka Connect and RBAC
          • Get Started With RBAC and Kafka Connect
          • Configure RBAC for a Connect Cluster
          • Configure RBAC for a Connect Worker
          • RBAC for self-managed connectors
          • Connect Secret Registry
          • Example Connect role-binding sequence
      • ksqlDB RBAC
      • REST Proxy Security
        • REST Proxy Security
        • REST Proxy Security Plugins
      • ZooKeeper Security
    • Security Management Tools
      • Ansible Playbooks for Confluent Platform
      • Docker Security for Confluent Platform
  • Multi-DC Deployment Architectures
    • Overview
    • Multi-Data Center Architectures
    • Cluster Linking
      • Cluster Linking Overview
      • Use Cases and Tutorials
        • Share Data Across Topics
        • Create Hybrid Cloud and Bridge-to-Cloud Deployments
        • Migrate Data
      • Configure, Manage, and Monitor
        • Manage Mirror Topics
        • Configure and Manage
        • Commands Reference
        • Monitor Metrics
        • Manage Security
      • FAQ
    • Multi-Region Clusters
      • Overview
      • Tutorial: Multi-Region Clusters
      • Transition Standard Active-Passive Data Centers to a Multi-Region Stretched Cluster
    • Replicator for Multi-Datacenter Replication
      • Replicator Overview
      • Tutorial: Replicating Data Across Clusters
      • Active-active Demo
      • Download and Install
      • Configure and Run
      • Tuning Replicator
      • Monitoring Replicator
      • Replicator and Cross-Cluster Failover
      • Configuration Options
      • Migrate from MirrorMaker to Replicator
      • Replicator Verifier
      • Replicator to Cloud Configurations
  • Configure and Manage
    • Confluent Control Center (Legacy)
      • Control Center Overview
      • Installing and Configuring Control Center (Legacy)
        • Configuring
        • Configuration Reference
        • Check Control Center (Legacy) Version and Enable Auto-Update
        • Properties File
        • Connecting Control Center to Confluent Cloud
        • Confluent Monitoring Interceptors in Control Center (Legacy)
        • Installing Control Center (Legacy) on Kafka
        • Managing Confluent Platform Licenses
        • Troubleshooting Control Center (Legacy)
        • Upgrading Control Center (Legacy)
      • Clusters
      • Brokers
      • Topics Overview
        • Topics Overview
        • Create
        • View Topic Metrics
        • Message Browser
        • Manage Schemas for Topics
        • Edit Configuration Settings for Topics
        • Delete Topics
      • Connect
      • ksqlDB
      • Consumers
      • Replicators
      • Clusters
      • Control Center (Legacy) Alerts
        • Overview
        • Access Alerts and Alert History
        • Configure Alerts Properties
        • View and Manage Triggers
        • Manage Actions
        • Configure PagerDuty Emails with Alerts
        • REST API for Alerts History
        • Example Triggers and Actions
        • Troubleshooting Alerts
      • Security
    • Configuration Reference
      • Overview
      • Broker and Controller Configuration
      • Topic Configuration
      • Consumer Configuration
      • Producer Configuration
      • Connect Configuration
        • Overview
        • Sink Configurations
        • Source Configurations
      • Admin Client Configuration
      • License Configuration
      • Kafka Streams Configuration Reference
      • Kafka Streams Configuration Guide
      • Docker Configuration Parameters for Confluent Platform
      • Control Center Configurations
      • ZooKeeper Configurations
      • KRaft Configurations
      • ksqlDB Server Configurations
    • Change Configuration Settings Dynamically
    • CLI Tools for Confluent Platform
      • CLI Tools for Confluent Platform
      • Confluent CLI
    • Kafka Metadata Management
      • Metadata Management in Kafka
      • KRaft Overview
      • Configure KRaft
      • Configure ZooKeeper for Production
    • Configure a Multi-Node Environment with Docker
    • Confluent Platform Metadata Service (MDS)
      • Configure the Confluent Platform Metadata Service (MDS)
      • Configure Confluent Platform Components to Communicate with MDS over TLS/SSL
      • Configure mTLS Authentication and RBAC for Kafka Brokers
      • Configure Kerberos Authentication for Brokers Running MDS
      • Configure LDAP Authentication
      • Configure LDAP Group-Based Authorization for MDS
      • Configure MDS to Manage Centralized Audit Logs
      • Metadata Service Configuration Settings
      • Confluent Metadata API Reference
    • Confluent Metrics Reporter
    • Confluent Health+
      • Health+ Overview
      • Enable Health+
      • Health+ Intelligent Alerts
      • Health+ Monitoring Dashboard
      • Confluent Telemetry Reporter
      • Telemetry Reporter Metrics
      • Confluent Health+ FAQ
    • Confluent REST Proxy
      • Overview
      • Quick Start
      • Rest Proxy API Reference
      • Production Deployment
        • Confluent Server Admin APIs
          • Configuration
          • Security
        • Standalone REST Proxy
          • Overview
          • Configuration
          • Monitoring
          • Security
      • REST Proxy Tutorial
      • Connect to Confluent Cloud
    • Kafka Operations
      • Overview
      • Running Kafka in Production
      • Post Kafka Deployment
      • Self-Balancing Clusters
        • Self-Balancing Overview
        • Quick Start Demo (Docker)
        • Tutorial: Adding and Removing Brokers
        • Configuration Options and Commands
        • Performance and Resource Usage
      • Auto Data Balancing
        • Quick Start
        • Tutorial (Docker)
        • Command and Configuration Options
      • Monitoring Kafka with JMX
      • Confluent Metrics Reporter
      • Tiered Storage
    • Docker Operations
      • Overview
      • Kafka Monitoring and Metrics Using JMX
      • Configure Docker Logging
      • Mounting Docker External Volumes
    • Post Kafka Deployment
    • Kafka Streams Operations
      • Capacity Planning and Sizing
      • Monitoring Kafka Streams Applications
    • ksqlDB Operations
    • DevOps for Kafka with Kubernetes and GitOps
      • Overview
      • Kafka DevOps Case Studies
        • Case Study: Graduated Environments
        • Case Study: Manage Cloud Secrets
        • Case Study: Kafka Connect management with GitOps
  • Confluent Health+
    • Health+ Overview
    • Enable Health+
    • Health+ Intelligent Alerts
    • Health+ Monitoring Dashboard
    • Confluent Telemetry Reporter
    • Telemetry Reporter Metrics
    • Confluent Health+ FAQ
  • Confluent CLI
  • Release Notes
    • Release Notes
    • Component Changelogs
  • APIs and Javadocs
    • Overview
    • Kafka API Javadocs
      • Kafka Java Client APIs
      • Kafka Producer Java API
      • Kafka Consumer Java API
      • Kafka AdminClient Java API
      • Kafka Common Java API
      • Kafka Streams Java API
      • Kafka Connect Java API
    • Client APIs
      • Python Client API
      • .NET Client API
      • JavaScript Client API
      • Go Client API
      • C++ Client API
      • Java Client API
      • JMS Client
        • Overview
        • Development Guide
    • Confluent APIs
      • Confluent REST Proxy API
        • Overview
        • Quick Start
        • Rest Proxy API Reference
        • Production Deployment
          • Confluent Server Admin APIs
            • Configuration
            • Security
          • Standalone REST Proxy
            • Overview
            • Configuration
            • Monitoring
            • Security
        • REST Proxy Tutorial
        • Connect to Confluent Cloud
      • Connect REST API
      • ksqlDB REST API
      • Metadata API
      • Schema Registry API
  • Glossary

Link Self-Managed and Confluent Cloud Clusters for Hybrid Cloud and Bridge-to-Cloud Deployments¶

This tutorial provides an example of how to use Cluster Linking for hybrid use cases that link Confluent Platform and Confluent Cloud clusters.

What the tutorial covers¶

By the end of this tutorial, you will have configured two clusters, one on Confluent Platform and one on Confluent Cloud, and successfully used Cluster Linking to share topic data bidirectionally across the clusters, all without opening up your firewall to Confluent Cloud.

You will create a deployment with data flowing in both directions:

  • From Confluent Cloud to Confluent Platform

  • From Confluent Platform to Confluent Cloud

    • This direction will require a “source initiated” cluster link; a new feature introduced in Confluent Platform 7.1.0.

      ../../_images/source-initiated-cluster-link.png

In both cases, Confluent Platform brokers will initiate the connection to Confluent Cloud brokers. Therefore, you will not have to open up your firewall to let Confluent Cloud connect to your Confluent Platform brokers.

In the process, you will create various security credentials and configuration files to use with the Confluent Platform and Confluent Cloud commands. For a handy list of these, see the Configuration summary at the end of this tutorial.

To see what clusters can use Cluster Linking, see Supported Cluster Types.

../../_images/cluster-link-hybrid.png

Install Confluent Platform¶

Download and extract Confluent Platform version 7.1.0.

The rest of the tutorial expects these variables to be set:

export CONFLUENT_HOME=<CP installation directory>
export CONFLUENT_CONFIG=$CONFLUENT_HOME/etc/kafka

Add these two lines to your .bashrc or .bash-profile so that they are executed whenever you open a terminal window.

About prerequisites and command examples¶

Note

As a general guideline (not just for this tutorial), any customer-owned firewall that allows the cluster link connection from source cluster brokers to destination cluster brokers must allow the TCP connection to persist in order for Cluster Linking to work.

  • These instructions assume you have a local installation of Confluent Platform 7.1.0 or later, and Java 1.8 or 1.11 (needed for Confluent Platform). Install instructions for self-managed deployments are available in the documentation. If you are new to Confluent Platform, first work through the Quick Start for Apache Kafka using Confluent Platform, and then return to this tutorial.
  • This tutorial and the source-initiated link feature require Confluent Enterprise, and are not supported in Confluent Community or Apache Kafka®.
  • These examples assume that the Confluent Platform properties files are in the default installation locations, except as otherwise noted. This helps make it easier to copy/paste commands from the examples directly into your terminal.
  • With a default install of Confluent Platform, the Confluent CLI. and Cluster Linking commands should be available in $CONFLUENT_HOME/bin and properties files will be in the directory CONFLUENT_CONFIG ($CONFLUENT_HOME/etc/kafka/). You must have Confluent Platform running to access these commands. Once Confluent Platform is configured and running, you can type any command with no arguments to get help (for example, kafka-cluster-links).
  • This tutorial requires a Confluent Cloud login and the Confluent CLI. To learn more, see Get the latest version of Confluent Cloud in the Confluent Cloud Cluster Linking Quick Start as well as Migrate Confluent CLI. If you are new to Confluent Cloud, you might want to walk through that Quick Start first, and then return to this tutorial.
  • This tutorial requires that you run a Dedicated cluster in Confluent Cloud, which will incur Confluent Cloud charges.
  • The parameter password.encoder.secret is used to encrypt the credentials which will be stored in the cluster link. To learn more about this parameter, see Multi-Region Clusters.

Port and configuration mapping¶

The example deployment in this tutorial uses the following port and feature configurations, and assumes that services will run on localhost.

Confluent Platform
Kafka Brokers 9092
ZooKeeper 2181

Tip

  • These are example ports that are used for the purposes of this tutorial. Cluster Linking does not require you to use these exact ports. You may change them if needed.
  • If you have other processes using these ports, either quit the other processes, or modify the tutorial steps to use different ports.

Configure Kafka and ZooKeeper files¶

In $CONFLUENT_CONFIG, configure the following files to set up the Confluent Platform cluster.

Copy $CONFLUENT_CONFIG/zookeeper.properties to use as a basis for zookeeper-clusterlinking.properties.

Copy $CONFLUENT_CONFIG/server.properties to use as a basis for server-clusterlinking.properties.

File Configurations
zookeeper-clusterlinking.properties

dataDir=/tmp/zookeeper-clusterlinking (this must be modified)

clientPort=2181 (this is the default)

server-clusterlinking.properties

These must be added to the existing file:

inter.broker.listener.name=SASL_PLAINTEXT

sasl.enabled.mechanisms=SCRAM-SHA-512

sasl.mechanism.inter.broker.protocol=SCRAM-SHA-512

listener.name.sasl_plaintext.scram-sha-512.sasl.jaas.config=org.apache.kafka.common.security.scram.ScramLoginModule required username="kafka" password="kafka-secret";

confluent.reporters.telemetry.auto.enable=false

confluent.cluster.link.enable=true

password.encoder.secret=encoder-secret

These are modifications or uses of existing configs:

listeners=SASL_PLAINTEXT://:9092

advertised.listeners=SASL_PLAINTEXT://:9092

log.dirs=/tmp/kafka-logs-1

zookeeper.connect=localhost:2181 (should already be set this way)

offsets.topic.replication.factor=1 (should already be set this way)

confluent.license.topic.replication.factor=1 (should already be set this way)

Note

  • This example configures only one ZooKeeper and one Confluent Server broker, secured with SSL. This is fine for testing on your local machine, but in a production setting, you should have more Zookeepers and brokers, spread across different machines for fault tolerance and high availability, all secured with authentication and encryption.
  • For this example, the replication factors for important internal topics are set to 1, because this is a testing setup with only one broker. For production deployments, do not set the replication factor of these topics to 1. Generally, replication factors should be set to 3 or more, depending on the number of brokers.
  • The parameter password.encoder.secret is needed to encrypt the credentials which will be stored in the cluster link. To learn more about this parameter, see Multi-Region Clusters.

Start the Confluent Platform cluster¶

Run the following commands in separate command windows.

ZooKeeper and Confluent Server commands do not “complete” until you stop them, so these windows need to stay open while the applications are running.

Use another command window to serve as your main terminal in which to run commands that you expect to complete. (Examples of these are kafka-configs, kafka-topics, kafka-cluster-links, and in certain cases kafka-console-producer and kafka-console-consumer, although sometimes you may want to leave these last two running as well.)

../../_images/cluster-link-hybrid-command-windows.png
  1. In a new command window, start the ZooKeeper server for the Confluent Platform cluster.

    zookeeper-server-start $CONFLUENT_CONFIG/zookeeper-clusterlinking.properties
    
  2. Run commands to create SASL SCRAM credentials on the cluster for two users: one to be used by the Kafka cluster, and the other for running commands against the cluster.

    • Run this command to create credentials on the cluster for a user called “kafka” that will be used by the Kafka cluster itself.

      kafka-configs --zookeeper localhost:2181 --alter --add-config \
        'SCRAM-SHA-512=[iterations=8192,password=kafka-secret]' \
        --entity-type users --entity-name kafka
      
    • Run this command to create credentials on the cluster for a user called “admin” that you will use to run commands against this cluster.

      kafka-configs --zookeeper localhost:2181 --alter --add-config \
        'SCRAM-SHA-512=[iterations=8192,password=admin-secret]' \
        --entity-type users --entity-name admin
      
  3. Create a file with the admin credentials to authenticate when you run commands against the Confluent Platform cluster.

    Open a text editor, create a file called $CONFLUENT_CONFIG/CP-command.config and copy-paste in the following content:

    sasl.mechanism=SCRAM-SHA-512
    security.protocol=SASL_PLAINTEXT
    sasl.jaas.config=org.apache.kafka.common.security.scram.ScramLoginModule required \
      username="admin" \
      password="admin-secret";
    
  4. In a new command window, start a Confluent Server broker for the source cluster, passing the credentials as a part of the command.

    kafka-server-start $CONFLUENT_CONFIG/server-clusterlinking.properties
    
  5. Get the Confluent Platform cluster ID.

    kafka-cluster cluster-id --bootstrap-server localhost:9092 --config $CONFLUENT_CONFIG/CP-command.config
    

    Your output should resemble:

    Cluster ID: G1pnOMOxSjWYIX8xuR2cfQ
    

    In this case, G1pnOMOxSjWYIX8xuR2cfQ is the Confluent Platform cluster ID, referred to in these examples as $CP_CLUSTER_ID.

    Optionally, set an environment variable for this either in the local shell, or in a zsh or bash profile so that you can directly cut-and-paste commands in later steps:

    export CP_CLUSTER_ID=<CP-CLUSTER-ID>
    

Start the Confluent Cloud cluster¶

You need a Dedicated Confluent Cloud cluster with Public internet in order to run the rest of the commands. You may create one just for the purpose of this demo, and then delete it after the tutorial is over. You will incur charges for this cluster.

  1. Log on to Confluent Cloud using either the unified CLI or the Confluent Cloud CLI (see About prerequisites and command examples).

    This example uses the unified CLI command:

    confluent login
    
  2. View environments, and select the one you want to use by environment ID.

    confluent environment list
    

    An asterisk indicates the currently selected environment in the list. You can select a different environment as follows.

    confluent environment use <environment-ID>
    
  3. Use an existing Dedicated cluster in Confluent Cloud, or create a new one either from the Confluent Cloud Console or directly from the Confluent CLI as shown below:

    confluent kafka cluster create CLOUD-DEMO --type dedicated --cloud aws --region us-east-1 --cku 1 --availability single-zone
    

    Your output should resemble:

    It may take up to 5 minutes for the Kafka cluster to be ready.
    +--------------+---------------+
    | Id           | lkc-59oyn     |
    | Name         | MY-CLOUD-DEMO |
    | Type         | DEDICATED     |
    | Ingress      |            50 |
    | Egress       |           150 |
    | Storage      | Infinite      |
    | Provider     | aws           |
    | Availability | single-zone   |
    | Region       | us-east-1     |
    | Status       | PROVISIONING  |
    | Endpoint     |               |
    | ApiEndpoint  |               |
    | RestEndpoint |               |
    | ClusterSize  |             1 |
    +--------------+---------------+
    

    If you created a new Confluent Cloud cluster, you must wait for the cluster to be provisioned. This typically takes a few minutes, but can take longer. You will be notified in email when the cluster is ready for use.

  4. View your clusters.

    confluent kafka cluster list
    

    An asterisk indicates the currently selected cluster. You can select a different cluster as follows:

    confluent kafka cluster use <CC-CLUSTER-ID>
    

    Tip

    You can get information or take several types of actions on a cluster that is not currently selected by specifying its cluster ID. For example, confluent kafka cluster describe <cluster-ID>.

  5. Note the cluster ID for your Dedicated cluster, referred to as $CC-CLUSTER-ID in this tutorial.

    Optionally, set an environment variable for this either in the local shell, or in a zsh or bash profile so that you can directly cut-and-paste commands in later steps:

    export CC_CLUSTER_ID=<CC-CLUSTER-ID>
    

Populate the Confluent Platform cluster¶

These commands use the Confluent Platform CLI.

  1. Create a topic on the Confluent Platform cluster with a single partition so ordering is easier to see.

    kafka-topics --create --topic from-on-prem --partitions 1 --replication-factor 1 --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    

    You should get confirmation that the topic was successfully created.

    Created topic from-on-prem.
    

    You can get a list of existing topics as follows:

    kafka-topics --list --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    

    And get detailed information on a topic with the --describe option:

    kafka-topics --describe --topic from-on-prem --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    
  2. Send some messages to the from-on-prem topic on the source cluster, and fill it with data.

    seq 1 5 | kafka-console-producer --topic from-on-prem --bootstrap-server localhost:9092 --producer.config $CONFLUENT_CONFIG/CP-command.config
    

    The command should terminate without any output.

  3. Consume from the topic on the source cluster.

    Run a consumer to consume messages from the from-on-prem topic.

    kafka-console-consumer --topic from-on-prem --from-beginning --bootstrap-server localhost:9092 --consumer.config $CONFLUENT_CONFIG/CP-command.config
    

    If the topic successfully consumes the messages, your output will be:

    1
    2
    3
    4
    5
    

    Use keyboard command Ctrl+C to get the prompt back.

Set up privileges for the Confluent Cloud cluster¶

On Confluent Cloud:

  1. Create a user API key for your Confluent Cloud cluster to act as the destination in Confluent Platform to Confluent Cloud topic data mirroring.

    confluent api-key create --resource $CC_CLUSTER_ID
    
  2. Save the resulting API key and secret in a safe place. This tutorial refers to these as <CC-link-api-key> and <CC-link-api-secret>. This is the API key and secret associated with the Confluent Cloud cluster that you will use to create the Confluent Platform to Confluent Cloud link. You will add these to a configuration file in the next step.

    Important

    If you are setting this up in production, you should use a service account API key instead of a user-associated key. A guide on how to set up privileges to access Confluent Cloud clusters with a service account is provided in the topic data sharing tutorial. For source-initiated links, the only ACL your service account will need is ALTER on the destination cluster (Cluster: Alter ACL). To learn more about ACLs for cluster linking, see the Security for Cluster Linking on Confluent Platform and the Security for Cluster Linking on Confluent Cloud

Mirror data from on-premises to Confluent Cloud¶

The following sections describe how to set up and test the Confluent Platform to Confluent Cloud link.

Create a Confluent Platform to Confluent Cloud link¶

Set up the cluster link that mirrors data from Confluent Platform to Confluent Cloud.

Tip

This tutorial shows how to create a cluster link from Confluent Platform to Confluent Cloud. That said, you can use the same general configuration if the destination is Confluent Platform 7.0 or later; you would create cluster link in the same way.

This is a source initiated link, meaning that its connection will come from Confluent Platform and go to Confluent Cloud. As such, you won’t have to open your on-premise firewall.

To create this source initiated link, you must create both halves of the cluster link: the first half on Confluent Cloud, the second half on Confluent Platform.

  1. Create a cluster link on the Confluent Cloud cluster.

    1. Create a link configuration file $CONFLUENT_CONFIG/clusterlink-hybrid-dst.config with the following entries:

      link.mode=DESTINATION
      connection.mode=INBOUND
      

      The combination of the configurations link.mode=DESTINATION and connection.mode=INBOUND tell the cluster link that it is the Destination half of a source initiated cluster link. These two configurations must be used together.

      Note

      • This tutorial example is based on the assumption that there is only one listener. If you configure multiple listeners (for example, INTERNAL, REPLICATION and EXTERNAL) and want to switch to a different listener than the default, you must add one more parameter to the configuration: local.listener.name=EXTERNAL. To learn more, see the Confluent Platform documentation on Configuration Options and Understanding Listeners in Cluster Linking
      • If you want to add any configurations to your cluster link (such as consumer offset sync or auto-create mirror topics) clusterlink-hybrid-dst.config is the file where you would add them. Cluster link configurations are always set on the Destination cluster link (not the Source cluster link).
    2. Create the destination cluster link on Confluent Cloud.

      confluent kafka link create from-on-prem-link --cluster $CC_CLUSTER_ID \
        --source-cluster $CP_CLUSTER_ID \
        --config-file $CONFLUENT_CONFIG/clusterlink-hybrid-dst.config
      

      Tip

      --source-cluster-id was replaced with --source-cluster in version 3 of confluent CLI, as described in the command reference for confluent kafka link create.

      The output from this command should indicate that the link was created.

      Created cluster link "from-on-prem-link".
      

      Tip

      You can list and describe the cluster links on Confluent Cloud with the following commands:

      confluent kafka link list --cluster $CC_CLUSTER_ID
      
      confluent kafka --cluster $CC_CLUSTER_ID link configuration list <link-name>
      
  2. Create security credentials for the cluster link on Confluent Platform. This security credential will be used to read topic data and metadata from the source cluster.

    kafka-configs --bootstrap-server localhost:9092 --alter --add-config \
      'SCRAM-SHA-512=[iterations=8192,password=1LINK2RUL3TH3MALL]' \
      --entity-type users --entity-name cp-to-cloud-link \
      --command-config $CONFLUENT_CONFIG/CP-command.config
    

    Your output should resemble:

    Completed updating config for user cp-to-cloud-link.
    
  3. Create a link configuration file $CONFLUENT_CONFIG/clusterlink-CP-src.config for the source cluster link on Confluent Platform with the following entries:

    link.mode=SOURCE
    connection.mode=OUTBOUND
    
    bootstrap.servers=<CC-BOOTSTRAP-SERVER>
    ssl.endpoint.identification.algorithm=https
    security.protocol=SASL_SSL
    sasl.mechanism=PLAIN
    sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required username='<CC-link-api-key>' password='<CC-link-api-secret>';
    
    local.listener.name=SASL_PLAINTEXT
    local.security.protocol=SASL_PLAINTEXT
    local.sasl.mechanism=SCRAM-SHA-512
    local.sasl.jaas.config=org.apache.kafka.common.security.scram.ScramLoginModule required username="cp-to-cloud-link" password="1LINK2RUL3TH3MALL";
    
    • The combination of configurations link.mode=SOURCE and connection.mode=OUTBOUND tell the cluster link that it is the source-half of a source initiated cluster link. These configurations must be used together.
    • The middle section tells the cluster link the bootstrap.servers of the Confluent Cloud destination cluster for it to reach out to, and the authentication credentials to use. Cluster Linking to Confluent Cloud uses TLS and SASL_PLAIN. This is needed so that the Confluent Cloud cluster knows to accept the incoming request. The Confluent Cloud bootstrap server is shown as the Endpoint in the output for confluent kafka cluster describe $CC_CLUSTER_ID , or in cluster settings on the Confluent Cloud console. If you use the Endpoint from the CLI output, remove the protocol prefix. For example, if the endpoint shows as SASL_SSL://pkc-r2ymk.us-east-1.aws.confluent.cloud:9092, your entry in $CONFLUENT_CONFIG/clusterlink-CP-src.config should be bootstrap.servers=pkc-r2ymk.us-east-1.aws.confluent.cloud:9092.
    • The last section, where lines are prefixed with local, contains the security credentials to use with the source cluster (Confluent Platform) to read data.
    • Note that the authentication mechanisms and security protocols for Confluent Platform map to what is defined in the broker. Those for Confluent Cloud map to what will be defined in a file called clusterlink-cloud-to-CP.config in a subsequent step. To learn more about the authentication and security protocols used, see Authentication with SASL using JAAS.

    Caution

    Do not add any cluster link configurations (such as consumer offset sync or auto-create mirror topics) to clusterlink-CP-src.config. These configurations must be set on the Destination’s cluster link (not the Source cluster’s cluster link).

  4. Create the source cluster link on Confluent Platform, using the following command, specifying the configuration file from the previous step.

    kafka-cluster-links --bootstrap-server localhost:9092 \
         --create --link from-on-prem-link \
         --config-file $CONFLUENT_CONFIG/clusterlink-CP-src.config \
         --cluster-id $CC_CLUSTER_ID --command-config $CONFLUENT_CONFIG/CP-command.config
    

    Your output should resemble:

    Cluster link 'from-on-prem-link' creation successfully completed.
    

    Tip

    • You can list cluster links on Confluent Platform with this command:

      kafka-cluster-links --list --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
      
    • The command to create the cluster link uses the Confluent Platform kafka-cluster-links to talk with the Confluent Platform cluster, which is different from the unified Confluent CLI used to talk with the Confluent Cloud cluster.

Create topics and mirror data to Confluent Cloud¶

Note

  • When using Schema Linking: To use a mirror topic that has a schema with Confluent Cloud Connect, ksqlDB, broker-side schema validation, or the topic viewer, make sure that make sure that Schema Linking puts the schema in the default context of the Confluent Cloud Schema Registry. To learn more, see How Schemas work with Mirror Topics.
  • Before running the first command in the steps below, make sure that you are still logged in to Confluent Cloud and have the appropriate environment and cluster selected. To list and select these resources, use the commands confluent kafka environment list, confluent kafka environment use, confluent kafka cluster list, and confluent kafka cluster use. A selected environment or cluster is indicated by an asterisk next to it in the output of list commands. The commands won’t work properly if no resources are selected (or if the wrong ones are selected).

Perform the following tasks logged in to Confluent Cloud.

  1. Create a mirror topic.

    The following command establishes a mirror of the original from-on-prem topic, using the cluster link from-on-prem-link.

    confluent kafka mirror create from-on-prem --link from-on-prem-link
    

    The command output will be:

    Created mirror topic "from-on-prem".
    
    • The mirror topic name must match the original topic name. To learn more, see all Known Limitations.
    • A mirror topic must specify the link to its source topic at creation time. This ensures that the mirror topic is a clean slate, with no conflicting data or metadata.
  2. List the mirror topics on the link.

    confluent kafka mirror list --cluster $CC_CLUSTER_ID
    

    Your output will resemble:

          Link Name     | Mirror Topic Name | Num Partition | Max Per Partition Mirror Lag | Source Topic Name | Mirror Status | Status Time Ms
    +-------------------+-------------------+---------------+------------------------------+-------------------+---------------+----------------+
      from-on-prem-link | from-on-prem      |             1 |                            0 | from-on-prem      | ACTIVE        |  1633640214250
    
  3. Consume from the mirror topic on the destination cluster to verify it.

    Still on Confluent Cloud, run a consumer to consume messages from the mirror topic to consume the messages you originally produced to the Confluent Platform topic in previous steps.

    confluent kafka topic consume from-on-prem --from-beginning
    

    Your output should be:

    1
    2
    3
    4
    5
    

    Note

    If when you attempt to run the consumer you get an error indicating “no API key selected for resource”, run this command to specify the <CC-API-KEY> for the Confluent Cloud destination cluster, then re-run the consumer command: confluent api-key use <CC-API-KEY> --resource $CC_CLUSTER_ID, or follow the instructions on the CLI provided with the error messages.

Mirror data from Confluent Cloud to on-premises¶

The following sections describe how to set up and test the Confluent Cloud to Confluent Platform link.

Create the Confluent Cloud to Confluent Platform link¶

  1. Create another user API key for this cluster link on your Confluent Cloud cluster.

    confluent api-key create --resource $CC_CLUSTER_ID
    

    You use the same cluster that served as the destination in previous steps as the source cluster in the following steps, therefore, you create a different API key and secret for the same cluster to serve in this new role.

  2. Keep the resulting API key and secret in a safe place. This tutorial refers to these as <CC-src-api-key> and <CC-src-api-secret>. You will add these to a configuration file in the next step.

    Important

    If you are setting this up in production, you should use a service account API key instead of a user-associated key. To do this, you would create a service account for your cluster link, give the service account the requisite ACLs, then create an API key for the service account. It’s best practice for each cluster link to have its own API key and service account. A guide on how to set up privileges to access Confluent Cloud clusters with a service account is provided in the topic data sharing tutorial.

  3. Use confluent kafka cluster describe to get the Confluent Cloud cluster Endpoint URL.

    confluent kafka cluster describe $CC_CLUSTER_ID
    

    This Endpoint URL will be referred to as <CC-BOOTSTRAP-SERVER> in the following steps.

  4. Save your API key and secret, along with the following configuration entries, in a file called $CONFLUENT_CONFIG/clusterlink-cloud-to-CP.config that the Confluent Platform commands will use to authenticate into Confluent Cloud:

    <vi | emacs> $CONFLUENT_CONFIG/clusterlink-cloud-to-CP.config
    

    The configuration entries you need in this file are as follows:

    bootstrap.servers=<CC-BOOTSTRAP-SERVER>
    security.protocol=SASL_SSL
    sasl.mechanism=PLAIN
    sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required username='<CC-src-api-key>' password='<CC-src-api-secret>';
    

    Tip

    • A copy-paste of this file into a vi or Emacs editor should result in each of these statements being on one line. Make sure that the lines are not broken up. The last line starting with sasl.jaas.config= should show all on one line in your file (as should the others). Supply values for your Confluent Cloud bootstrap server, and API key and secret, then save the file.
    • Note that the values for security.protocol and sasl.mechanism map to what you defined for Confluent Cloud in clusterlink-CP-src.config.
  5. Create the cluster link to Confluent Platform.

    If you want to follow this example exactly, name the cluster link from-cloud-link but you have the option to name it whatever you like. You will use the cluster link name to create and manipulate mirror topics. You cannot rename a cluster link once it’s created.

    The following command creates the cluster link on an unsecured Confluent Platform cluster. If you have security set up on your Confluent Platform cluster, you must pass security credentials to this command with --command-config as shown in Setting Properties on a Cluster Link.

    kafka-cluster-links --bootstrap-server localhost:9092 \
          --create --link from-cloud-link \
          --config-file $CONFLUENT_CONFIG/clusterlink-cloud-to-CP.config \
          --cluster-id $CC_CLUSTER_ID --command-config $CONFLUENT_CONFIG/CP-command.config
    

    Your output should resemble the following:

    Cluster link 'from-cloud-link' creation successfully completed.
    
  6. Check that the link exists with the kafka-cluster-links --list command, as follows.

    kafka-cluster-links --list --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    

    Your output should resemble the following, showing the previous from-on-prem-link you created along with the new from-cloud-link

    Link name: 'from-on-prem-link', link ID: '7eb4304e-b513-41d2-903e-147dea62a01c', remote cluster ID: 'lkc-1vgo6', local cluster ID: 'G1pnOMOxSjWYIX8xuR2cfQ'
    Link name: 'from-cloud-link', link ID: 'b1a56076-4d6f-45e0-9013-ff305abd0e54', remote cluster ID: 'lkc-1vgo6', local cluster ID: 'G1pnOMOxSjWYIX8xuR2cfQ'
    

Create topics and mirror data to on-premises¶

  1. In Confluent Cloud, use the unified Confluent CLI to create a topic with one partition called cloud-topic.

    confluent kafka topic create cloud-topic --partitions 1
    
  2. In another command window on Confluent Cloud, start a producer to send some data into cloud-topic.

    confluent kafka topic produce cloud-topic --cluster $CC_CLUSTER_ID
    
    • Verify that the producer has started. Your output will resemble the following to show that the producer is ready.

      $ confluent kafka topic produce cloud-topic --cluster lkc-1vgo6
      Starting Kafka Producer. Use Ctrl-C or Ctrl-D to exit.
      
    • Type some entries of your choice into the producer window, pressing Return after each entry to send.

      Riesling
      Pinot Blanc
      Verdejo
      
  3. Mirror the cloud-topic on Confluent Platform, using the command kafka-mirrors --create --mirror-topic <topic-name>.

    The following command establishes a mirror of the original cloud-topic, using the cluster link from-cloud-link.

    kafka-mirrors --create --mirror-topic cloud-topic --link from-cloud-link --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    

    You should get this verification that the mirror topic was created.

    Created topic cloud-topic.
    
  4. On Confluent Platform, check the mirror topic status by running kafka-mirrors --describe on the from-cloud-link.

    kafka-mirrors --describe --link from-cloud-link --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    

    Your output will show the status of any mirror topics on the specified link.

    Topic: cloud-topic        LinkName: from-cloud-link       LinkId: b1a56076-4d6f-45e0-9013-ff305abd0e54    MirrorTopic: cloud-topic        State: ACTIVE   StateTime: 2021-10-07 16:36:20
              Partition: 0    State: ACTIVE   DestLogEndOffset: 2     LastFetchSourceHighWatermark: 2 Lag: 0  TimeSinceLastFetchMs: 384566
    
  5. Consume the data from the on-premises mirror topic.

    kafka-console-consumer --topic cloud-topic --from-beginning --bootstrap-server localhost:9092 --consumer.config $CONFLUENT_CONFIG/CP-command.config
    

    Your output should match the entries you typed into the Confluent Cloud producer in step 8.

    ../../_images/cluster-link-hybrid-produce-consume.png
  6. View the configuration of your cluster link:

    kafka-configs --describe --cluster-link from-cloud-link --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    

    The output for this command is a list of configurations, partially shown in the following example.

    Dynamic configs for cluster-link from-cloud-link are:
    metadata.max.age.ms=300000 sensitive=false synonyms={}
    reconnect.backoff.max.ms=1000 sensitive=false synonyms={}
    auto.create.mirror.topics.filters= sensitive=false synonyms={}
    ssl.engine.factory.class=null sensitive=false synonyms={}
    sasl.kerberos.ticket.renew.window.factor=0.8 sensitive=false synonyms={}
    reconnect.backoff.ms=50 sensitive=false synonyms={}
    consumer.offset.sync.ms=30000 sensitive=false synonyms={}
    
    ...
    
    link.mode=DESTINATION sensitive=false synonyms={}
    security.protocol=SASL_SSL sensitive=false synonyms={}
    acl.sync.ms=5000 sensitive=false synonyms={}
    ssl.keymanager.algorithm=SunX509 sensitive=false synonyms={}
    sasl.login.callback.handler.class=null sensitive=false synonyms={}
    replica.fetch.max.bytes=5242880 sensitive=false synonyms={}
    availability.check.consecutive.failure.threshold=5 sensitive=false synonyms={}
    sasl.login.refresh.window.jitter=0.05 sensitive=false synonyms={}
    

Teardown¶

Stop consumers and producers¶

Stop consumers and producers with Ctl-C in their respective command windows.

Promote mirror topics¶

Promote the mirror topics to normal topics.

  1. On Confluent Cloud promote the mirror topic called from-on-prem:

    confluent kafka mirror promote from-on-prem --link from-on-prem-link --cluster $CC_CLUSTER_ID
    

    Your output will resemble:

     Mirror Topic Name | Partition | Partition Mirror Lag | Error Message | Error Code | Last Source Fetch Offset
    +-------------------+-----------+----------------------+---------------+------------+--------------------------+
     from-on-prem      |         0 |                    0 |               |            |                        9
    

    If you want to verify that the mirroring stopped, you can re-run the above command. You should get a message in the Error Message column that Topic 'from-on-prem' has already stopped its mirror from 'from-on-prem-link'.

  2. On Confluent Platform, promote the mirror topic called cloud-topic:

    kafka-mirrors --promote --topics cloud-topic --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    

    Your output should resemble:

    Calculating max offset and ms lag for mirror topics: [cloud-topic]
    Finished calculating max offset lag and max lag ms for mirror topics: [cloud-topic]
    Request for stopping topic cloud-topics mirror was successfully scheduled. Please use the describe command with the --pending-stopped-only option to monitor progress.
    

    If you retry this command, you will get an error indicating that the Topic 'cloud-topic' has already stopped its mirror 'from-cloud-link'.

Delete the source and mirror topics¶

Tip

  • To list the topics on Confluent Cloud: confluent kafka topic list
  • To list the topics on Confluent Platform: kafka-topics --list --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
  1. Delete the topics on Confluent Cloud.

    confluent kafka topic delete cloud-topic
    
    confluent kafka topic delete from-on-prem
    
  2. Delete the topics from Confluent Platform.

    kafka-topics --delete --topic cloud-topic --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    
    kafka-topics --delete --topic from-on-prem --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
    

Delete the cluster links¶

  1. Delete the cluster links on Confluent Platform.

    • List the cluster links on Confluent Platform.

      kafka-cluster-links --list --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
      

      There will be two because one was required for the source initiated link and the other to act as the destination for Confluent Cloud data:

      Link name: 'from-on-prem-link', link ID: '7eb4304e-b513-41d2-903e-147dea62a01c', remote cluster ID: 'lkc-1vgo6' local cluster ID: ', local cluster ID: 'G1pnOMOxSjWYIX8xuR2cfQ'' remote cluster available: 'true'
      Link name: 'from-cloud-link', link ID: 'b1a56076-4d6f-45e0-9013-ff305abd0e54', remote cluster ID: 'lkc-1vgo6' local cluster ID: ', local cluster ID: 'G1pnOMOxSjWYIX8xuR2cfQ'' remote cluster available: 'true'
      
    • Delete the cluster links on Confluent Platform, using kafka-cluster-links --delete <link-name>.

      kafka-cluster-links --delete --link from-on-prem-link --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
      
      kafka-cluster-links --delete --link from-cloud-link --bootstrap-server localhost:9092 --command-config $CONFLUENT_CONFIG/CP-command.config
      

      You will get confirmation that the links were deleted as output for each command.

  2. Delete the cluster links on Confluent Cloud.

    • List the cluster links on Confluent Cloud.

      confluent kafka link list
      

      Your output will resemble:

            Link Name     |   Source Cluster Id
      +-------------------+------------------------+
        from-on-prem-link | G1pnOMOxSjWYIX8xuR2cfQ
      
    • Delete the cluster link on Confluent Cloud, using confluent kafka link delete <link-name>.

      confluent kafka link delete from-on-prem-link
      

      You will get confirmation that the link was deleted.

Stop Confluent Platform and ZooKeeper¶

Stop all of the other components with Ctl-C in their respective command windows, in reverse order in which you started them.

  1. Stop the Kafka broker first.
  2. When the Kafka broker has fully shut down and your prompt has returned, then go to the other window and stop the associated ZooKeeper.

Configuration summary¶

File Purpose
zookeeper-clusterlinking.properties Configuration file used for ZooKeeper startup, as described in Configure Kafka and ZooKeeper files
server-clusterlinking.properties Configuration file used for the Confluent Platform cluster startup, as described in Configure Kafka and ZooKeeper files
CP-command.config
  • Created in step 3 of Start the Confluent Platform cluster
  • Contains admin credentials to authenticate when you run commands against the Confluent Platform cluster
  • Used with the flag –command-config in Confluent Platform commands
clusterlink-hybrid-dst.config
  • Created in step 1 of Create a Confluent Platform to Confluent Cloud link
  • Specifies the link configuration for the Confluent Cloud cluster to serve as the destination
  • Used to create the cluster link from-on-prem-link on Confluent Cloud side
clusterlink-CP-src.config
  • Created in step 3 of Create a Confluent Platform to Confluent Cloud link
  • Specifies the link configuration for the Confluent Platform cluster that serves as the source, includes credentials and connection information for Confluent Platform to authenticate into Confluent Cloud
  • Used to create the cluster link from-on-prem-link on the Confluent Platform side
clusterlink-cloud-to-CP.config
  • Created in step 4 of Create the Confluent Cloud to Confluent Platform link
  • Contains security credentials and connection information that the Confluent Platform commands use to authenticate into Confluent Cloud
  • Used to create the from-cloud-link on the Confluent Platform side

Related content¶

  • Blog post: The Link To Cloud: How to Build a Seamless and Secure Hybrid Data Bridge with Cluster Linking
  • Cloud Cluster Linking Quick Start (Confluent Cloud)
  • Security Considerations for Cluster Linking (Confluent Cloud)
  • Cluster Linking Security (on Confluent Platform)
  • Share Data Across Clusters, Regions, and Clouds (Confluent Cloud) (in-depth tutorial, including detail on how to set up service accounts for cluster links, a best practice production level deployments.)
  • Cluster Linking Configuration, Commands, and Management (Confluent Cloud)
  • Tutorial: Using Cluster Linking for Topic Data Sharing (Confluent Platform)
  • Cluster Linking Commands Reference (Confluent Platform)

Was this doc page helpful?

Give us feedback

Do you still need help?

Confluent support portal Ask the community
Thank you. We'll be in touch!
Be the first to get updates and new content

By clicking "SIGN UP" you agree that your personal data will be processed in accordance with our Privacy Policy.

  • Confluent
  • About
  • Careers
  • Contact
  • Professional Services
  • Product
  • Confluent Cloud
  • Confluent Platform
  • Connectors
  • Flink
  • Stream Governance
  • Developer
  • Free Courses
  • Tutorials
  • Event Streaming Patterns
  • Documentation
  • Blog
  • Podcast
  • Community
  • Forum
  • Meetups
  • Kafka Summit
  • Catalysts
Terms & Conditions Privacy Policy Do Not Sell My Information Modern Slavery Policy Cookie Settings Feedback

Copyright © Confluent, Inc. 2014- Apache®️, Apache Kafka®️, Kafka®️, Apache Flink®️, Flink®️, Apache Iceberg®️, Iceberg®️ and associated open source project names are trademarks of the Apache Software Foundation

On this page: