# Manage Kafka Clusters Using Control Center for Confluent Platform The Clusters page enables you to view tiles for healthy and unhealthy clusters at a glance or search for a cluster being managed by Control Center. What you see on the Clusters page varies depending on whether you are running Control Center in [Normal or Reduced infrastructure mode](overview.md#control-center-modes). The following image shows a example of the Clusters page in Normal mode. Click on a cluster tile for a view of metrics for that cluster.  ## Cluster overview page The overview page for a single Apache Kafka® cluster provides a summary view of the cluster and its connected services.  The following table describes the panels found on the Clusters page by mode. All of the panels are clickable and navigate you directly to the relevant sections. | Section | Normal mode | Reduced infrastructure mode | |-------------------------------------------------------------|----------------------------------------------------------------------------------------|---------------------------------------------| | [Brokers overview](brokers.md#c3-brokers-overview-metrics) | Total brokers with production and consumption throughput. | Not visible in Reduced infrastructure mode. | | [Topics overview](topics/overview.md#c3-all-topics) | Total topics, total partitions, under
replicated partitions, out of sync replicas. | Total topics and total partitions. | | [Connect overview](connect.md#c3-all-connect-clusters-page) | Number of Connect clusters and connector status. | Same as Normal mode. | | [ksqlDB overview](ksql.md#c3-ksql-clusters-page) | Number of ksqlDB clusters and persistent queries. | Same as Normal mode. | You can view and edit cluster properties and broker configurations in the Cluster settings pages. When you click the Cluster settings sub-menu for a cluster, the **General** tab appears by default. ## Edit a cluster name You can edit the cluster name and view the host details. The host field lock icon indicates it cannot be changed. To change the cluster name: 1. Click the cluster from the cluster navigation bar. 2. Click the **Cluster settings** menu. 3. Edit the cluster name in **Cluster Name** field. You should choose a human-friendly name for the cluster that follows these rules: - Cluster names can only include characters from the English alphabet, numbers, underscores (_), and dashes (-). - Cluster names are case-sensitive. The new cluster name is saved to the [Cluster Registry in Confluent Platform](/platform/current/security/cluster-registry.html#cluster-registry), if it is enabled. 4. Click **Save changes** to apply your changes.  ## View-only cluster configuration View the cluster configuration. If broker configuration editing is [disabled](#ff-c3-edit-broker-configs), the view is read-only and the [Edit Settings](#ff-c3-edit-broker-configs) feature is not available. #### IMPORTANT If [RBAC](security/c3-rbac.md#controlcenter-security-rbac) is enabled for Control Center, it takes : precedence over Access Control settings. The privileges associated with your assigned roles determine what you can view and access. To view a cluster configuration: 1. Click the cluster from the cluster navigation bar. 2. Click the **Cluster settings** menu. 3. Click the **Cluster defaults** tab.  Each setting section indicates if there are overrides applied to that setting. ## Edit dynamic cluster configuration settings The dynamic cluster configuration option is [enabled by default](#ff-c3-edit-broker-configs). The feature allows editing cluster configurations within Control Center that do not require a restart. Any configuration option that has a `per-broker` or `cluster-wide` Dynamic Update Mode can be edited. Any options designated as `read-only` for the dynamic update mode requires a restart and cannot be edited dynamically. For information about available broker configuration options, including the dynamic update mode per option, see [Kafka Broker and Controller Configuration Reference for Confluent Platform](/platform/current/installation/configuration/broker-configs.html#cp-config-brokers). To edit the cluster configuration: 1. Click the cluster from the cluster navigation bar. 2. Click the **Cluster settings** menu. 3. Click the **Cluster defaults** tab. 4. Find the section for the setting you want to edit, and click **Edit settings**. 1. Hover over the info icon for a configuration option to view its description. 2. Make your configuration changes. 3. Notice a blue undo icon indicates the setting was modified from the default value and you can set it back to the default by clicking the arrow. A gray undo icon indicates the settings is set to its default.  5. Click **Save** to save your changes, or **Cancel** to cancel edits to settings. To see examples of changing broker configurations dynamically using the Kafka command line kafka-configs tool, see [Dynamically change broker settings](/platform/current/kafka/dynamic-config.html#kafka-dyn-broker-config). ## Enable and disable dynamic editing of broker configurations The Dynamic Cluster Configuration feature that allows editing settings without a restart is enabled by default. The feature can be disabled in Control Center if an organization does not want any users to access the feature. After disabling the feature, the Edit Settings button in the Brokers tab in the Control Center UI is no longer visible. #### IMPORTANT If [RBAC](security/c3-rbac.md#controlcenter-security-rbac) is enabled for Control Center, it takes : precedence over Access Control settings. To disable the edit broker config settings feature in Control Center: 1. Set the `confluent.controlcenter.broker.config.edit.enable` option in your `control-center.properties` file to `false`. ```bash ... confluent.controlcenter.broker.config.edit.enable=false ... ``` #### NOTE Make the change in the appropriate Control Center properties files configured for your environments, including `control-center-dev.properties` or `control-center-production.properties`. The properties files are located in `/path-to-confluent/etc/confluent-control-center/`. 2. Restart Control Center and pass in the properties file for the configuration to take effect. For more information, see [Control Center Configuration Examples for Confluent Platform](installation/properties.md#c3-properties-files). - Local (dev) environment: #### IMPORTANT Do not use [confluent local](https://docs.confluent.io/confluent-cli/current/command-reference/local/index.html) for production use. ```bash confluent local services control-center stop confluent local services control-center start --config ../etc/confluent-control-center/control-center.properties ``` - Production environment: ```bash ./bin/control-center-stop ./bin/control-center-start ../etc/confluent-control-center/control-center.properties ``` To enable the feature again, set the option back to `true` and restart Control Center with the updated properties file. ## Work with Self-Balancing Clusters For a complete guide to Self-Balancing Clusters, see [Manage Self-Balancing Kafka Clusters in Confluent Platform](/platform/current/clusters/sbc/index.html#sbc), including a primer on [Configuration and monitoring](/platform/current/clusters/sbc/index.html#sbc-config-and-monitor) and comprehensive hands-on [tutorial](/platform/current/clusters/sbc/sbc-tutorial.html#sbc-tutorial). ### Monitor and configure Self-Balancing 1. Click the cluster from the cluster navigation bar. 2. Click the **Cluster settings** menu. 3. Click the **Self-balancing** tab.  4. To change dynamic configurations, click **Edit Settings**. Self-Balancing has several dynamic properties which can be configured while the cluster is running, including options to: - Turn Self-Balancing **On** or **Off**. In the example `server.properties` file that ships with Confluent Platform, [confluent.balancer.enable](/platform/current/clusters/sbc/configuration-options.html#sbc-config-enable) is set to `true`, which means Self-Balancing is on. - Override the default throttle value (10485760 or 10MB/sec), which determines the maximum network bandwidth available for Self-Balancing. ([confluent.balancer.throttle.bytes.per.second](/platform/current/clusters/sbc/configuration-options.html#sbc-config-throttle)) - Toggle the trigger condition for rebalance to either **Only when brokers are added or removed** (the default) or **Anytime**. ([confluent.balancer.heal.uneven.load.trigger](/platform/current/clusters/sbc/configuration-options.html#sbc-config-heal-uneven-load)) 5. Make changes and click **Save**. When Self-Balancing is on and set to trigger **Only when brokers are added or removed** (the default), the card on the Brokers overview shows “Workload optimizer” as “Disabled”.  When Self-Balancing is on, and set to trigger **Anytime**, the card on the Brokers overview shows “Workload optimizer” as “Balanced” if rebalancing is not in progress, or one of the work-in-progress statuses during a rebalance.  ### Remove a broker If you remove a broker from the cluster, Self-Balancing will redistribute topic data to the other brokers. A summary of this procedure is shown below. For a more detailed walkthrough, see [Remove a broker](/platform/current/clusters/sbc/sbc-tutorial.html#sbc-tutorial-c3-remove-broker) in the context of the [Tutorial: Add and Remove Brokers with Self-Balancing in Confluent Platform](/platform/current/clusters/sbc/sbc-tutorial.html#sbc-tutorial). #### IMPORTANT - In practice, you can remove a lead broker. It may cause a short delay in cluster balancing, which is why we suggest not doing so for this example. To learn more, [What happens if the lead broker (controller) is removed or lost?](/platform/current/clusters/sbc/index.html#sbc-faq-lost-leader). - If the broker you attempt to remove contains the only replica for a topic, the broker removal will fail. To learn more, see [Limitations](/platform/current/clusters/sbc/index.html#sbc-limitations). - Starting with Confluent Platform 7.3.0, Self-Balancing Clusters supports Apache Kafka® Raft Metadata mode (KRaft), see [KRaft: Apache Kafka without ZooKeeper](https://developer.confluent.io/learn/kraft/). If you are using [Self-balancing with Confluent for Kubernetes](https://docs.confluent.io/operator/current/co-scale-cluster.html#scale-cp-clusters-and-balance-data), and using CFK to shut down the broker, there is no further action needed. However, if you are running Confluent Platform outside of CFK on a KRaft supported version of Confluent Platform, and separately calling [kafka-remove-brokers](/platform/current/clusters/sbc/configuration-options.html#sbc-command-remove-brokers), you must take an additional action to call the `UnregisterBroker` API through `kafka-cluster.sh` after the broker removal is complete. If you call `kafka-remove-brokers` with `shouldShutdown=false`, you must manually remove the broker; if you set `shouldShutdown=true`, SBC will shut down the broker for you. In either case, on KRaft mode Confluent Platform deployments, you must call `UnregisterBroker` after broker shutdown is complete. This will cleanly remove all traces of the broker on the cluster. In non-KRaft Confluent Platform, this step is not required; but in KRaft mode, simply calling **kafka-remove-brokers** is not enough to remove all lingering metadata internally within the controllers. The `UnregisterBroker` API does this cleanup. 1. Remove a broker using the Control Center option on the **Brokers overview** page. - Select **Brokers**, scroll to the bottom of the Overview page to view the list of brokers currently online. - Select a broker to remove, to drill down to its monitoring details.  - At the bottom of this page, click **Remove broker**, then type REMOVE in the input field to verify that you want to take this action. When the broker removal is completed, click the confirm option to acknowledge. #### NOTE If you get an [error message](/platform/current/clusters/sbc/index.html#sbc-remove-broker-troubleshoot) that broker removal : failed due to insufficient metrics, Self-Balancing is still [initializing](/platform/current/clusters/sbc/configuration-options.html#sbc-initialization), which can take up to 30 minutes. If this happens, retry broker removal after several minutes, and it should succeed. 2. Use the Control Center to monitor the rebalance. On Control Center click **Cluster settings** > **Self-balancing** to track the progress. When the rebalance is complete, both the **Brokers overview** page and **Cluster settings** > **Broker defaults** will show only the remaining brokers, and not the one you removed. ### Suggested Resources - To learn more, see [Manage Self-Balancing Kafka Clusters in Confluent Platform](/platform/current/clusters/sbc/index.html#sbc). - For troubleshooting related to Self-Balancing and Control Center, see [Self-Balancing options do not show up on Control Center](/platform/current/clusters/sbc/index.html#sbc-not-on-c3-troubleshoot), [Broker metrics are not displayed on Control Center](/platform/current/clusters/sbc/index.html#sbc-broker-metrics-not-shown-on-c3-troubleshoot), and [Consumer lag reflected on Control Center](/platform/current/clusters/sbc/index.html#sbc-ignore-consumer-lag-on-c3-troubleshoot) in the [Self-balancing Clusters troubleshooting section](/platform/current/clusters/sbc/index.html#sbc-troubleshooting). ## Configure Tiered Storage For a complete guide to setting up and working with Tiered Storage, see [Tiered Storage in Confluent Platform](/platform/current/clusters/tiered-storage.html#tiered-storage). To configure and work with Tiered Storage starting from Control Center: 1. Click the cluster from the cluster navigation bar. 2. Click the **Cluster settings** menu. 3. Click the **Tiered storage** tab.  You can hide or show the on-screen setup instructions, which walk through cloud provider setup as fully described in [Tiered Storage in Confluent Platform](/platform/current/clusters/tiered-storage.html#tiered-storage). 4. To view and edit dynamic settings, click **Edit settings**.  View or change settings and click **Cancel** or **Save changes** as appropriate. 5. To set up storage, choose a cloud provider (click the **GCS** or **S3** tab). The S3 configuration options are shown here as an example.  6. Specify property values and paths to your credentials, then click **Generate configurations**.  7. Copy the generated configurations block and paste it into the properties files for your brokers (for example, `$CONFLUENT_HOME/etc/kafka/server.properties`).  #### IMPORTANT - The same bucket must be used across all brokers within a Tiered Storage enabled cluster. This applies to all supported platforms. - The Tiered Storage internal topic defaults to a replication factor of `3`. If you use `confluent local services start` to run a single broker cluster such as that described in [Quick Start guides](/platform/current/get-started/platform-quickstart.html#quickstart),’ you must add an additional line to the broker file, `$CONFLUENT_HOME/etc/kafka/server.properties`: `confluent.tier.metadata.replication.factor=1` - As a recommended best practice, do not set a retention policy on the cloud storage (such as an AWS S3 bucket) because this may conflict with the Kafka topic retention policy. 8. After you update these configurations to enable Tiered Storage, restart the brokers. This can be done in a [rolling](/platform/current/kafka/post-deployment.html#rolling-restart) fashion. 9. Cluster-wide metrics for **Tiered Storage** are shown on the **Tiered Storage** card on the **Brokers** overview page for the cluster.  Click into these initial stats to view a metrics chart for Tiered Storage.  Hover and slide the cursor over a chart to get details on data at any particular point in time.  10. To get storage metrics on a specific topic, navigate to the topic (choose **Cluster > Topics**, select a topic from the list). The **Storage** card is shown on the Overview page for the topic.