Control Center (Legacy) Configuration Reference

The following settings are available for configuring Control Center (Legacy).

Important

Do not use double-quotes to wrap character strings in properties files. You can, however, use double-quotes in header values.

Base settings

You configure Control Center (Legacy) with a configuration properties file, which is passed to Control Center (Legacy) on start. Several sample configuration (.properties) files are provided with Confluent Control Center (Legacy), and are provided under the $CONFLUENT_HOME/etc/confluent-control-center directory. For a list of sample configuration files, see Control Center (Legacy) Properties File.

bootstrap.servers

A list of host/port pairs to use for establishing the initial connection to the Apache Kafka® cluster. The client will make use of all servers irrespective of which servers are specified here for bootstrapping; this list only impacts the initial hosts used to discover the full set of servers. This list should be in the form host1:port1,host2:port2,.... Since these servers are just used for the initial connection to discover the full cluster membership (which could change dynamically), this list need not contain the full set of servers (you may want more than one, though, in case a server is down).

  • Type: list
  • Default: localhost:9092
  • Importance: high
confluent.license

Confluent issues an enterprise license key to each subscriber, allowing the subscriber to unlock the full functionality of Control Center (Legacy). The license key is text that you can copy and paste. Paste the license key as the value for confluent.license. You can also manage the license in the Control Center (Legacy) web interface.

A trial license allows using for a 30-day trial period. A developer license allows using Control Center (Legacy) and other Confluent Platform proprietary components indefinitely for single-broker development environments. Trial and developer licenses are shipped with Confluent Platform.

See Managing Confluent Platform Licenses in Control Center (Legacy) for more details.

If you are a subscriber, contact Confluent Support for more information about obtaining another valid enterprise license before it expires. confluent.controlcenter.license is a deprecated synonym for this configuration key.

  • Type: string
  • Default: “”
  • Importance: high
confluent.controlcenter.rest.csrf.prevention.enable

When enabled, uses a token-based system to help prevent Cross-Site Request Forgery (CSRF). CSRF is a malicious exploit that can result in an end user executing unwanted actions on a web application in which they’re currently authenticated. If the target user has an administrative account, CSRF can compromise the entire web application.

  • Type: boolean
  • Default: false
  • Importance: medium
confluent.controlcenter.rest.csrf.prevention.token.expiration.minutes

Sets the CSRF prevention token expiration time, if CSRF prevention is enabled. The default expiration time should be sufficent for most use cases, however you can use this setting to increase or decrease the token expiration interval time if needed.

  • Type: int
  • Default: 30
  • Importance: low

Production Settings

In production, you should run Control Center (Legacy) in a cluster that is separate from the Kafka clusters being monitored. Set the following configuration parameters in the Control Center (Legacy) properties file.

confluent.controlcenter.streams.cache.max.bytes.buffering

Maximum number of memory bytes used for record caches across all threads.

Tip

Consider setting this config value proportional to the total num.partitions. Here is an example computation:

  • Each per-partition metric is stored as a key-value pair that consists of “topic-string, partition-id, cluster-name”. Control Center (Legacy) compacts the values as four long variables, recording the min, max, count, and total.
  • X is the total topic partitions and seven per-partition metrics that Control Center (Legacy) collects.
  • Twelve threads by default.

The total cache size should be:

X (topic partitions) * 7 (per-partition metrics) * 12 (number of threads) * 150 (average bytes per metric).

For example, with 100000 topic partitions, the cache size should be 1,260,000,000 bytes.

  • Type:
  • Default: 1,073,741,824 bytes
  • Importance: high
confluent.controlcenter.kafka.<name>.bootstrap.servers

Bootstrap servers for any additional Kafka cluster being monitored. Replace <name> with the name Control Center (Legacy) should use to identify this cluster. For example, using confluent.controlcenter.kafka.production-nyc.bootstrap.servers, Control Center (Legacy) will show the additional cluster with the name production-nyc in the cluster list.

  • Type: list
  • Default: “”
  • Importance: high
confluent.controlcenter.kafka.<name>.<connection config>

Any additional connection configuration required to connect to the Kafka cluster identified by <name> can be specified using the confluent.controlcenter.kafka.<name>. prefix. For example, to specify the security.protocol=SASL_SSL configuration for the cluster named production-nyc, add confluent.controlcenter.kafka.production-nyc.security.protocol=SASL_SSL to the configuration.

  • Importance: medium

Tip

If you are configuring a multi-cluster deployment, see also confluent.controlcenter.streams.name.cprest.url.

Logging

By default, Control Center (Legacy) outputs its logs to stdout. Logging configuration is defined in etc/confluent-control-center/log4j.properties. Confluent also provides etc/confluent-control-center/log4j-rolling.properties as an example of setting up Control Center (Legacy) with rolling log files that are easier to manage. You can select your desired log4j configuration by setting the CONTROL_CENTER_LOG4J_OPTS environment variable when starting Control Center (Legacy).

Optional settings

Confluent allows you to change some other parameters that change how Control Center (Legacy) behaves, such as internal topic names, data file locations, and replication settings. The default values for most of these settings are suitable for production use, but you can change these if needed.

Mode

Use this setting to specify the mode that Confluent Control Center (Legacy) starts in. By default, Control Center (Legacy) starts in Normal mode, meaning all is specified, and monitoring is enabled.

confluent.controlcenter.mode.enable

Set the mode in which Control Center (Legacy) should be started. Valid values are all, meaning Confluent Control Center (Legacy) operates normally, and management meaning Confluent Control Center (Legacy) uses less infrastructure to operate. In Reduced infrastructure mode, Control Center (Legacy) is used to manage Kafka clusters only and will not display monitoring or metrics information.

  • Type: string
  • Default: all
  • Importance: high

General

confluent.controlcenter.connect.<connect-cluster-name>.cluster

Comma-separated list of Kafka Connect worker URLs for the Connect cluster specified by <connect-cluster-name>. <connect-cluster-name can be an arbitrary string used to identify individual connect clusters and does not need to correspond to any worker setting. Control Center (Legacy) will connect to a single worker. If a worker fails, Control Center (Legacy) will try the request against a different worker. This must be set if you want to manage a Connect cluster. The URL should include the protocol (HTTP or HTTPS) and its associated port (8083 or 8443 respectively).

  • Type: list
  • Default: “”
  • Importance: high
  • Example HTTP: confluent.controlcenter.connect.myconnectclustername.cluster=http://localhost:8083
confluent.controlcenter.connect.healthcheck.endpoint

Provides the default discovery path for connect clusters. If you are using the community version of Confluent Platform, set this property to /connectors to display the connect clusters in Control Center (Legacy).

  • Type: string
  • Default: /v1/metadata/id
  • Importance: high
confluent.controlcenter.connect.cluster

Deprecated since Confluent Platform version 6.2. Comma-separated list of Connect worker URLs within a single cluster. This is deprecated by confluent.controlcenter.connect.<connect-cluster-name>.cluster.

  • Type: list
  • Default: “”
  • Importance: low
confluent.controlcenter.data.dir

Location for Control Center (Legacy)-specific data. Although the data stored in this directory can be recomputed, doing so is expensive and can affect the availability of Control Center (Legacy)’s stream monitoring functionality. For production, you should set this to a durable, writable, and secure location.

  • Type: path
  • Default: /var/lib/confluent-control-center (control-center-production.properties)
  • Default: /tmp/confluent/control-center (control-center.properties, control-center-dev.properties, control-center-minimal.properties)
  • Importance: high
confluent.controlcenter.rest.listeners

Comma-separated list of listeners that listen for API requests over either http or https. If a listener uses https, the appropriate SSL configuration parameters need to be set as well. The first value will be used as a Control Center (Legacy) link in the body of eligible alert emails sent from Control Center (Legacy). For details, see Alerts history.

  • Type: list
  • Default: http://0.0.0.0:9021
  • Importance: high
confluent.controlcenter.rest.advertised.url

Externally visible host. Control Center (Legacy) uses this as an override to rest.listeners when generating URLs for external communications such as alert emails.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.rest.access.control.allow.origin

Sets the value for Jetty Access-Control-Allow-Origin header.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.rest.response.http.headers.config

Use to select which HTTP headers are returned in the HTTP response for Confluent Platform components. Specify multiple values in a comma-separated string using the format [action][header name]:[header value] where [action] is one of the following: set, add, setDate, or addDate. You must use quotation marks around the header value when the header value contains commas. For example:

response.http.headers.config="add Cache-Control: no-cache, no-store, must-revalidate", add X-XSS-Protection: 1; mode=block, add Strict-Transport-Security: max-age=31536000; includeSubDomains, add X-Content-Type-Options: nosniff
  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.streams.cprest.url

Defines the REST endpoints for Control Center (Legacy) to enable HTTP servers on the broker(s). A comma-separated list with multiple values can be provided for a multi-broker cluster.

For examples, see Configure Control Center (Legacy) with REST endpoints and advertised listeners, Required Configurations for Control Center (Legacy), and Self-Balancing Clusters documentation.

  • Type: list
  • Default: http://localhost:8090
  • Importance: high

To configure multiple clusters, see confluent.controlcenter.kafka.name.cprest.url.

confluent.controlcenter.kafka.<name>.cprest.url

Defines the REST endpoints for any additional Kafka clusters being monitored by Control Center (Legacy) to enable HTTP servers on the broker(s). Replace <name> with the name that identifies this cluster. This name should be consistent with the Kafka cluster name used for other Control Center configurations. A comma-separated list with multiple values can be provided for a multi-broker cluster.

Note that if the REST API endpoints are secured with TLS/SSL, you must include additional properties in the Confluent Control Center (Legacy) properties file that provide the security information. For more information, see Configure TLS/SSL for Control Center (Legacy) as a server and TLS/SSL settings for web access.

The following example shows REST endpoint settings for three clusters or data centers (dc1, dc2, and dc3):

confluent.controlcenter.streams.cprest.url=https://dc1:8090
confluent.controlcenter.kafka.dc2.cprest.url=https://dc2:8090
confluent.controlcenter.kafka.dc3.cprest.url=https://dc3:8090
  • Type: list
  • Default: “”
  • Importance: high

For an example of configuring the Control Center (Legacy) cprest.url specifically for multiple clusters, see Enabling Multi-Cluster Schema Registry.

confluent.controlcenter.schema.registry.url

Schema Registry URL. For more information and examples, see the Schema Registry documentation and configuration steps for Enabling Multi-Cluster Schema Registry.

confluent.controlcenter.id

Identifier used as a prefix so that multiple instances of Control Center (Legacy) can co-exist.

  • Type: string
  • Default: “1”
  • Importance: low
confluent.controlcenter.name

Control Center (Legacy) Name

  • Type: string
  • Default: _confluent-controlcenter-7.3.15
  • Importance: low
confluent.controlcenter.internal.topics.partitions

Number of partitions used internally by Control Center (Legacy).

  • Type: int
  • Default: 12
  • Importance: low
confluent.controlcenter.internal.topics.replication

Replication factor used internally by Control Center (Legacy). It is not recommended to reduce this value except in a development environment.

  • Type: int
  • Default: 3
  • Importance: low
confluent.controlcenter.internal.topics.retention.ms

Maximum time in milliseconds that internal data is stored in Kafka. For more information, see data retention.

  • Type: long
  • Default: 604,800,000 (7 days)
  • Importance: low
confluent.controlcenter.internal.topics.changelog.segment.bytes

Segment size in bytes for internal changelog topics in Kafka. This must be as small as broker settings log.cleaner.dedupe.buffer.size / log.cleaner.threads to guarantee enough space in the broker’s dedupe buffer for compaction to work.

  • Type: long
  • Default: 134,217,728
  • Importance: low
confluent.metrics.topic

Topic from which metrics data will be read. For multiple instances of Control Center (Legacy) using the same Kafka cluster for monitoring purposes, it may be helpful to use separate metrics and command topics (if each Control Center (Legacy) installation is monitoring different Kafka clusters).

  • Type: string
  • Default: _confluent-metrics
  • Importance: low
confluent.metrics.topic.retention.ms

Maximum time in milliseconds that metrics data is stored in Kafka. For more information, see data retention.

  • Type: long
  • Default: 259,200,000 (3 days)
  • Importance: low
confluent.metrics.topic.replication

Replication factor for metrics topic. It is not recommended to reduce this value except in a development environment.

  • Type: int
  • Default: 3
  • Importance: low
confluent.metrics.topic.partitions

Partition count for metrics topic.

  • Type: int
  • Default: 12
  • Importance: low
confluent.metrics.topic.skip.backlog.minutes

Skip backlog older than x minutes ago for broker metrics data. Set this to 0 if you want to process from the latest offsets. This config overrides confluent.controlcenter.streams.consumer.auto.offset.reset (deprecated) for the metrics input topic.

  • Type: long
  • Default: 15
confluent.controlcenter.disk.skew.warning.min.bytes

Threshold for the max difference in disk usage across all brokers before disk skew warning is published.

  • Type: long
  • Default: 1,073,741,824
  • Importance: low
confluent.controlcenter.max.trigger.events.per.alert.config

The maximum number of trigger events in one alert.

  • Type: int
  • Default: 1,000
  • Importance: low
confluent.controlcenter.alert.cluster.down.autocreate

Auto create a trigger and an email action for Control Center’s cluster down alerts. For more information, see Control Center (Legacy) cluster down status.

  • Type: boolean
  • Default: false
  • Importance: low
confluent.controlcenter.alert.cluster.down.to.email

Email to send alerts to when Control Center’s cluster is down.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.alert.cluster.down.to.webhookurl.slack

The Slack webhook URL to post alerts to when Control Center’s cluster is down.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.alert.cluster.down.to.pagerduty.integration.key

The PagerDuty integration key to post alerts to a certain service when Control Center (Legacy)’s cluster is down.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.alert.cluster.down.send.rate

Send rate per hour for auto-created cluster down alerts. Default: 12 times per hour (every 5 minutes).

  • Type: int
  • Default: 12
  • Importance: low
confluent.controlcenter.ui.data.expired.threshold

Configure a threshold (in seconds) before data is considered out of date. Default: 120 seconds (2 minutes).

  • Type: int
  • Default: 120
  • Importance: low
confluent.controlcenter.service.healthcheck.interval.sec

The interval (in seconds) used for checking the health of Confluent Platform nodes. This includes ksqlDB, Connect, Schema Registry, REST Proxy, and Metadata Service (MDS).

  • Type: int
  • Default: 20
  • Importance: low
confluent.controlcenter.request.buffer.size.bytes

Allows adjustment of the RequestBuffer size of HttpClient.

  • Type: int
  • Default: 10,000
  • Importance: low
confluent.controlcenter.topic.inspection.max.message.bytes

Maximum size of messages to display on the Messages page for a topic. Messages larger than this value are suppressed and an error (MESSAGE_TOO_BIG_FOR_UI) is shown. Metadata is displayed even if the the message is suppressed.

Large messages can slow down or crash the Messages page.

  • Type: long
  • Default: 1048576 (1 Mb)
  • Importance: low
confluent.controlcenter.one.minute.rollup.topics.retention.ms

The retention period, in milliseconds, for one-minute aggregated metrics topics. Default: 345,600,000 milliseconds (4 days).

To change the default value, append a new value in milliseconds to the property, then increment confluent.controlcenter.id and restart Confluent Control Center (Legacy). For example, confluent.controlcenter.one.minute.rollup.topics.retention.ms=864000000

The minimum retention of roll up is 60000 (one minute).

  • Type: long
  • Default: 345600000
  • Importance: low
confluent.controlcenter.three.hour.rollup.topics.retention.ms

The retention period, in milliseconds, for three-hour aggregated metrics topics. Default: 60,566,400,000 milliseconds (701 days).

To change the default value, append the new value in milliseconds to the property, then increment confluent.controlcenter.id and restart Confluent Control Center (Legacy). For example, confluent.controlcenter.three.hour.rollup.topics.retention.ms=864000000

The minimum retention of roll up is 10800000 (three hours).

  • Type: long
  • Default: 60566400000
  • Importance: low

Broker UI settings

Starting with Confluent Platform version 7.0.0, Control Center (Legacy) uses an embedded REST proxy and as a result provides an updated UI to display broker settings. The new settings UI is enabled by default, but you can revert back to the old view with the following settings:

confluent.controlcenter.embedded.kafkarest.enable

Enables or disables the use of an embedded REST proxy for Control Center (Legacy), which must be enabled for Confluent Control Center (Legacy) to display the new broker settings UI.

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.ui.brokersettings.kafkarest.enable

Enables or disables new broker settings UI. This setting will be forced to false if confluent.controlcenter.ui.brokersettings.kafkarest.enable is also false.

  • Type: boolean
  • Default: true
  • Importance: low

Monitoring settings

These optional settings are for consumption and end-to-end latency monitoring. The default settings work for the majority of use cases and scales.

confluent.monitoring.interceptor.topic

The Kafka topic that stores monitoring interceptor data. This setting must match the confluent.monitoring.interceptor.topic configuration used by the interceptors in your application. Usually you should not change this setting unless you are running multiple instances of Control Center (Legacy) with client monitoring interceptor data being reported to the same Kafka cluster.

  • Type: string
  • Default: _confluent-monitoring
  • Importance: high
confluent.monitoring.interceptor.topic.partitions

Number of partitions for the monitoring interceptor data topic.

  • Type: int
  • Default: 12
  • Importance: low
confluent.monitoring.interceptor.topic.replication

Replication factor for monitoring topic. It is not recommended to reduce this value except in a development environment.

  • Type: int
  • Default: 3
  • Importance: low
confluent.monitoring.interceptor.topic.retention.ms

Maximum time in milliseconds that interceptor data is stored in Kafka. For more information, see data retention.

  • Type: long
  • Default: 259,200,000 (3 days)
  • Importance: low
confluent.monitoring.interceptor.topic.skip.backlog.minutes

Skip backlog older than x minutes ago for monitoring interceptor data. Set this to 0 if you want to process from the latest offsets. This config overrides confluent.controlcenter.streams.consumer.auto.offset.reset (deprecated) for the monitoring input topic.

  • Type: long
  • Default: 15
  • Importance: low

Basic Authentication settings for web access

These optional settings allow you to enable and configure authentication for accessing the Control Center (Legacy) web interface. See the UI Authentication guide for more details on configuring authentication.

confluent.controlcenter.rest.authentication.method

Authentication method to use. Available options: NONE, BASIC, BEARER.

Important

When RBAC is enabled in Control Center (Legacy), the method must be BEARER. For more information, see Configure RBAC for Control Center (Legacy).

  • Type: string
  • Default: NONE
  • Importance: low
confluent.controlcenter.rest.authentication.realm

Realm to be used by Control Center (Legacy) when authenticating.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.rest.authentication.roles

Roles that are authenticated to access Control Center (Legacy).

  • Type: string
  • Default: *
  • Importance: low
confluent.controlcenter.auth.restricted.roles

List of roles with limited read-only access. No editing or creating using the UI. Add topic and Edit Topic Configs options are disabled. Roles added here must also be included in confluent.controlcenter.rest.authentication.roles.

  • Type: list
  • Default: “”
  • Importance: low

Important

For users with restricted (read-only) roles, the following user interface (UI) features and options are unavailable (hidden):

  • Add, delete, pause, or resume connectors
  • Browse connectors
  • View connector settings
  • Upload connector configs
  • Create, delete, or edit alerts (triggers or actions)
  • Edit a license
  • Edit brokers
  • Press submit on cluster forms
  • Edit, create, or delete schemas
  • Edit data flow queries
  • Inspect topics
  • Type in the KSQL editor
  • Run or stop ksqlDB querie
  • Add ksqlDB streams or table

Note

For fine-grained access control, consider configuring role-based access control (RBAC).

confluent.controlcenter.auth.session.expiration.ms

Timeout in milliseconds after which a user session will have to be re-authenticated with the authentication service (e.g. LDAP). Defaults to 0, which means authentication is done for every request. Increase this value to avoid calling the LDAP service for each request.

  • Type: long
  • Default: 0
  • Importance: low

TLS/SSL settings for web access

Configure the following properties to secure web access (HTTPS) to Control Center (Legacy) with TLS/SSL.

To configure TLS/SSL settings when Control Center (Legacy) acts as a proxy server to other Confluent Platform components, see Configure TLS/SSL for Control Center (Legacy).

confluent.controlcenter.rest.listeners

Comma-separated list of listeners that listen for API requests over either http or https. If a listener uses https, the appropriate SSL configuration parameters need to be set as well. The first value will be used as a Control Center (Legacy) link in the body of eligible alert emails sent from Control Center (Legacy). For details, see Alerts history.

  • Type: list
  • Default: http://0.0.0.0:9021
  • Importance: high
confluent.controlcenter.rest.ssl.keystore.location

Used for HTTPS. Location of the keystore file to use for TLS/SSL.

Important

Jetty requires that the key’s CN stored in the keystore must match the FQDN.

  • Type: string
  • Default: “”
  • Importance: high
confluent.controlcenter.rest.ssl.keystore.password

Used for HTTPS. The store password for the keystore file.

  • Type: password
  • Default: “”
  • Importance: high
confluent.controlcenter.rest.ssl.key.password

Used for HTTPS. The password of the private key in the keystore file.

  • Type: password
  • Default: “”
  • Importance: high
confluent.controlcenter.rest.ssl.truststore.location

Used for HTTPS. Location of the truststore. Required only to authenticate HTTPS clients.

  • Type: string
  • Default: “”
  • Importance: high
confluent.controlcenter.rest.ssl.truststore.password

Used for HTTPS. The store password for the truststore file.

  • Type: password
  • Default: “”
  • Importance: high
confluent.controlcenter.rest.ssl.keystore.type

Used for HTTPS. The type of keystore file.

  • Type: string
  • Default: JKS
  • Importance: medium
confluent.controlcenter.rest.ssl.truststore.type

Used for HTTPS. The type of truststore file.

  • Type: string
  • Default: JKS
  • Importance: medium
confluent.controlcenter.rest.ssl.protocol

Used for HTTPS. The TLS/SSL protocol used to generate the SslContextFactory.

  • Type: string
  • Default: TLS
  • Importance: medium
confluent.controlcenter.rest.ssl.provider

Used for HTTPS. The TLS/SSL security provider name. Leave blank to use the defaults for Jetty.

  • Type: string
  • Default: “” (Jetty default)
  • Importance: medium
confluent.controlcenter.rest.ssl.client.auth

Deprecated. Used for HTTPS. Whether to require the HTTPS client to authenticate using the server’s truststore. This is deprecated by confluent.controlcenter.rest.ssl.client.authentication.

  • Type: boolean
  • Default: false
  • Importance: medium
confluent.controlcenter.rest.ssl.client.authentication

Used for HTTPS. Valid values: NONE, REQUESTED or REQUIRED. NONE disables TLS/SSL client authentication, REQUESTED requests but doesn’t require TLS/SSL client authentication, and REQUIRED requires HTTPS clients to authenticate using the server’s truststore. This config overrides confluent.controlcenter.rest.ssl.client.auth (deprecated).

  • Type: string
  • Default: NONE
  • Importance: medium
confluent.controlcenter.rest.ssl.enabled.protocols

Used for HTTPS. The list of protocols enabled for TLS/SSL connections. Comma-separated list. Leave blank to use the Jetty default.

  • Type: list
  • Default: “” (Jetty default)
  • Importance: medium
confluent.controlcenter.rest.ssl.keymanager.algorithm

Used for HTTPS. The algorithm used by the key manager factory for TLS/SSL connections. Leave blank to use the Jetty default.

  • Type: string
  • Default: “” (Jetty default)
  • Importance: low
confluent.controlcenter.rest.ssl.trustmanager.algorithm

Used for HTTPS. The algorithm used by the trust manager factory for TLS/SSL connections. Leave blank to use the Jetty default.

  • Type: string
  • Default: “” (Jetty default)
  • Importance: low
confluent.controlcenter.rest.ssl.cipher.suites
A comma-separated list of TLS/SSL cipher suites used for HTTPS. Leave blank to use the Jetty default or specify any combination of the following suites:

  • TLS_AES_256_GCM_SHA384

  • TLS_CHACHA20_POLY1305_SHA256

  • TLS_AES_128_GCM_SHA256

  • TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384

  • TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

  • TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256

  • TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256

  • TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256

  • TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256

    Using another cipher suite name will cause Confluent Control Center (Legacy) to fail to start. Ciphers listed here are not supported. Do not use them.

    • Type: list
    • Default: “” (Jetty default)
    • Importance: low
confluent.controlcenter.rest.ssl.endpoint.identification.algorithm

Used for HTTPS. The endpoint identification algorithm to validate the server hostname using the server certificate. Leave blank to use the Jetty default.

  • Type: string
  • Default: https
  • Importance: low
confluent.controlcenter.use.default.jvm.truststore

Enable Control Center (Legacy) to fallback to use the default JVM trust store.

  • Type: string
  • Default: false
  • Importance: low
confluent.controlcenter.use.default.os.truststore

Enable Control Center (Legacy) to fallback to use the default operating system trust store.

  • Type: string
  • Default: false
  • Importance: low

Security for Confluent Platform components

The following settings control TLS/SSL encryption between Control Center (Legacy) and Confluent Platform components or features. You can also configure Basic authentication for Schema Registry.

You should configure these settings if you have configured your Kafka cluster with these security features. For TLS/SSL, you can choose to configure each component separately, or set a single store.

Streams

These settings are the standard Kafka authentication and authorization settings prefixed with confluent.controlcenter.streams..

confluent.controlcenter.streams.security.protocol

Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.

  • Type: string
  • Default: PLAINTEXT
  • Importance: low
confluent.controlcenter.streams.ssl.keystore.location

The location of the keystore file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.streams.ssl.keystore.password

The store password for the keystore file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.streams.ssl.key.password

The password of the private key in the keystore file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.streams.ssl.truststore.location

The location of the truststore file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.streams.ssl.truststore.password

The password for the truststore file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.streams.sasl.mechanism

SASL mechanism used for client connections. This may be any mechanism for which a security provider is available. GSSAPI is the default mechanism.

  • Type: string
  • Default: GSSAPI
  • Importance: low
confluent.controlcenter.streams.sasl.kerberos.service.name

The Kerberos principal name that Kafka runs as. This can be defined either in Kafka’s JAAS config or in Kafka’s config.

  • Type: string
  • Default: null
  • Importance: low

Schema Registry

Specify the following property when Basic Authentication is enabled for Schema Registry.

confluent.controlcenter.schema.registry.basic.auth.credentials.source

Defines how to select the credentials for HTTP Basic Authentication header for a single Schema Registry cluster, or the first Schema Registry in a multi-cluster Schema Registry deployment. The supported values are URL, USER_INFO, and SASL_INHERIT.

  • Type: string
  • Default: URL
  • Importance: medium

Note

Specifying control.center.schema.registry.basic.auth.credentials.source, as shown, passes basic.auth.credentials.source to the Schema Registry client.

confluent.controlcenter.schema.registry.<sr-cluster-name>.basic.auth.credentials.source

Defines how to pick the credentials for HTTP Basic Authentication header on a Schema Registry cluster in a multi-cluster Schema Registry deployment. The supported values are URL, USER_INFO, and SASL_INHERIT.

  • Type: string
  • Default: URL
  • Importance: medium
confluent.controlcenter.schema.registry.basic.auth.user.info

Specifies the user credentials for HTTP Basic Authentication in the form of {username}:{password} for a single Schema Registry cluster, or the first Schema Registry cluster in a multi-cluster Schema Registry deployment.

  • Type: string
  • Default: “”
  • Importance: medium
confluent.controlcenter.schema.registry.<sr-cluster-name>.basic.auth.user.info

Specifies the user credentials for HTTP Basic Authentication in the form of <username>:<password> for Schema Registry clusters in a multi-cluster Schema Registry deployment (associated with the URL fields by <sr-cluster-name>).

  • Type: string
  • Default: “”
  • Importance: medium

Specify the following set of properties when TLS/SSL is enabled for Schema Registry.

confluent.controlcenter.schema.registry.schema.registry.ssl.truststore.location

The location of the truststore file for Schema Registry.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.schema.registry.schema.registry.ssl.truststore.password

The password for the truststore file for Schema Registry.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.schema.registry.schema.registry.ssl.keystore.location

The location of the keystore file for Schema Registry.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.schema.registry.schema.registry.ssl.keystore.password

The store password for the keystore file for Schema Registry.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.schema.registry.schema.registry.ssl.key.password

The password of the private key in the keystore file for Schema Registry.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.schema.registry.schema.registry.alias.name

Specifies an alias for the certificate Schema Registry uses during mTLS. Use the following format to specify <Certificate-Alias> as an alias.

confluent.controlcenter.schema.registry.schema.registry.alias.name=<Certificate-Alias>

If you have multiple trustStores, each certificate should have a unique alias, even if you are using the same certificate for multiple connections.

  • Type: string
  • Default: “”
  • Importance: low

Connect

Specify the following property when Basic Authentication is enabled for Connect.

confluent.controlcenter.connect.<connect-cluster-name>.basic.auth.user.info

Specifies the user credentials for HTTP Basic Authentication in the form of <username>:<password> for connectors. (associated with the URL fields by <connect-cluster-name>.

  • Type: string
  • Default: “”
  • Importance: medium

Specify the following set of properties when TLS/SSL is enabled for Connect.

confluent.controlcenter.connect.connect.ssl.truststore.location

The location of the truststore file for Connect.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.connect.connect.ssl.truststore.password

The stored password for the truststore for Connect.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.connect.connect.ssl.keystore.location

The location of the keystore file for Connect.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.connect.connect.ssl.keystore.password

The store password for the keystore file for Connect.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.connect.connect.ssl.key.password

The password of the private key in the keystore file for Connect.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.connect.connect.alias.name

Specifies an alias for the certificate Connect uses during mTLS. Use the following format to specify <Certificate-Alias> as an alias.

confluent.controlcenter.connect.connect.alias.name=<Certificate-Alias>

If you have multiple trustStores, each certificate should have a unique alias, even if you are using the same certificate for multiple connections.

  • Type: string
  • Default: “”
  • Importance: low

ksqlDB

Specify the following property when Basic Authentication is enabled for ksqlDB.

confluent.controlcenter.ksql.<ksql-cluster-name>.basic.auth.user.info

Specifies the user credentials for HTTP Basic Authentication in the form of <username>:<password> for ksqlDB clusters associated with the URL fields by <ksqldb-cluster-name>.

  • Type: string
  • Default: “”
  • Importance: medium

Specify the following set of properties when TLS/SSL is enabled for ksqlDB.

confluent.controlcenter.ksql.ksql.ssl.truststore.location

The location of the truststore file for ksqlDB.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.ksql.ksql.ssl.truststore.password

The stored password for the truststore file for ksqlDB.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.ksql.ksql.ssl.keystore.location

The location of the keystore file for ksqlDB.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.ksql.ksql.ssl.keystore.password

The stored password for the keystore file for ksqlDB.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.ksql.ksql.ssl.key.password

The password of the private key in the keystore file for ksqlDB.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.ksql.ksql.alias.name

Specifies an alias for the certificate ksqlDB uses during mTLS. Use the following format to specify <Certificate-Alias> as an alias.

confluent.controlcenter.ksql.ksql.alias.name=<Certificate-Alias>

If you have multiple trustStores, each certificate should have a unique alias, even if you are using the same certificate for multiple connections.

  • Type: string
  • Default: “”
  • Importance: low

Single proxy server store

Instead of specifying TLS/SSL settings for each component, you can specify that Confluent Control Center (Legacy) use a single proxy server truststore and keystore that contain all the TLS/SSL settings for all the components.

confluent.controlcenter.rest.proxy.ssl.truststore.location

The location of the the truststore file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.rest.proxy.ssl.truststore.password

The stored password for the truststore file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.rest.proxy.ssl.keystore.location

The location of the keystore file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.rest.proxy.ssl.keystore.password

The stored password for the password file.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.rest.proxy.ssl.key.password

The password of the private key in the keystore file.

  • Type: string
  • Default: “”
  • Importance: low

RBAC settings

Metadata Service (MDS) and other settings required for implementing RBAC in Control Center (Legacy). For a complete configuration example of essential settings, see Configure RBAC for Control Center (Legacy).

confluent.metadata.bootstrap.server.urls

A comma-separated list of valid URLs that specify where the RBAC metadata server or servers can be reached. This configuration is required to run Control Center (Legacy) inside an RBAC environment.

  • Type: long
  • Default: 0
  • Importance: low
confluent.metadata.basic.auth.user.info

Formatted as USERNAME:PASSWORD, the credentials of an RBAC user for Control Center (Legacy) to act on behalf of. This includes running Kafka Streams, authorizing requests, and interacting with other Confluent Platform services. This configuration is required to run Control Center (Legacy) inside an RBAC environment.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.auth.bearer.issuer

JWT token issuer.

  • Type: string
  • Default: “”
  • Importance: low
public.key.path

Path to public key for authenticating JWT tokens.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.auth.bearer.roles.claim

JWT roles claim.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.auth.bearer.token.max.lifetime.ms

Bearer token issued during login cannot renew itself beyond this duration. The maximum value: 86400000 (24 hours). If you set this to more than 24 hours, the system overrides your setting and uses 24 hours.

  • Type: long
  • Default: “”
  • Importance: low

Cluster Registry settings

Version 6.0.1 of Confluent Platform and later includes the option to enable the Cluster Registry for Control Center (Legacy), which creates a more user-friendly RBAC role binding experience and enables centralized audit logging.

confluent.metadata.cluster.registry.enable

The value for this flag is True if the cluster registry is enabled. When enabled, cluster information will be read from the cluster registry.

  • Type: boolean
  • Default: false

Note

If this feature flag is enabled, the following flags will be ignored:

  • confluent.controlcenter.kafka.<name>.bootstrap.servers
  • confluent.controlcenter.kafka.<name>.<connection config>

An exception to this rule occurs when you need to specify additional flags, such as confluent.controlcenter.kafka.<name>.ssl.keystore.location.

confluent.metadata.cluster.registry.merge.configuration.enable

When enabled, the configuration information for Kafka clusters in the properties file is merged with the one from cluster registry. This enables users to configure additional properties that cannot be added to cluster registry (for example, confluent.controlcenter.kafka.<name>.ssl.keystore.location).

  • Type: boolean
  • Default: true
confluent.controlcenter.purge.stale.cluster.enable

When enabled, Control Center (Legacy) will purge stale cluster information from the command store.

  • Type: boolean
  • Default: false

Email settings

These optional settings control the SMTP server and account used when an alerts triggers the email action.

Important

The body of the email alert is populated with the first hostname specified in the confluent.controlcenter.rest.listeners property. The default value is localhost:9021.

confluent.controlcenter.mail.enabled

Enable email alerts. If this setting is false, you cannot add email alert actions in the web user interface.

  • Type: boolean
  • Default: false
  • Importance: low
confluent.controlcenter.mail.host.name

Hostname of outgoing SMTP server.

  • Type: string
  • Default: localhost
  • Importance: low
confluent.controlcenter.mail.port

SMTP port open on confluent.controlcenter.mail.host.name.

  • Type: int
  • Default: 587
  • Importance: low
confluent.controlcenter.mail.ssl.checkserveridentity

Forces the use of SSL and validation of the server’s certificate. Enabling this flag causes Control Center (Legacy) to use the port set by confluent.controlcenter.mail.ssl.port instead of confluent.controlcenter.mail.port.

  • Type: boolean
  • Default: false
  • Importance: low
confluent.controlcenter.mail.ssl.port

SSL-specific SMTP port to open on confluent.controlcenter.mail.host.name. Setting confluent.controlcenter.mail.ssl.checkserveridentity to true forces the use of this port and not the confluent.controlcenter.mail.port.

  • Type: int
  • Default: 465
  • Importance: low
confluent.controlcenter.mail.from

The originating address for emails sent from Control Center (Legacy).

confluent.controlcenter.mail.bounce.address

Override for confluent.controlcenter.mail.from config to send message bounce notifications.

  • Type: string
  • Importance: low
confluent.controlcenter.mail.starttls.required

Forces using STARTTLS.

  • Type: boolean
  • Default: false
  • Importance: low
confluent.controlcenter.mail.username

Username for username/password authentication. Authentication with your SMTP server only performs if this value is set.

  • Type: string
  • Importance: low
confluent.controlcenter.mail.password

Password for username/password authentication.

  • Type: string
  • Importance: low

Webhook settings

confluent.controlcenter.webhook.enabled

Enable supported webhook alerts. If this setting is false, you cannot add webhook alert actions in the web user interface.

  • Type: boolean
  • Default: true
  • Importance: low

Feature settings

These settings enable Confluent Control Center (Legacy) features such as message inspection, broker configurations, license manager, ksqlDB Overview, and Schema Registry. They apply to all clusters managed by the current Control Center (Legacy) installation. Most features are enabled by default except the deprecated views for legacy System Health and Streams Monitoring.

confluent.controlcenter.topic.inspection.enable

Enable users to inspect topics.

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.broker.config.edit.enable

Enable user access to Edit dynamic cluster configuration settings.

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.license.manager.enable

Enable License Manager in Control Center (Legacy).

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.consumers.view.enable

Enable the Consumers view in Control Center (Legacy).

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.ksql.enable

Enable user access to the ksqlDB GUI.

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.schema.registry.enable

Enable user access to Manage Schemas for Topics in Control Center (Legacy).

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.ui.autoupdate.enable

Enable auto updating the Control Center (Legacy) UI.

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.usage.data.collection.enable

Data collection is disabled, and this property has no effect regardless of its value. Enable or disable data collection in Control Center (Legacy).

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.ui.replicator.monitoring.enable

Enable Replicator monitoring in the Control Center (Legacy) UI.

  • Type: boolean
  • Default: true
  • Importance: low
confluent.controlcenter.ui.controller.chart.enable

Enable the Active Controller chart to display within the Broker uptime panel in the Control Center (Legacy) UI.

  • Type: boolean
  • Default: false
  • Importance: low

ksqlDB settings

You can use Control Center (Legacy) to interact with ksqlDB Server, which runs separately from your Kafka clusters. For access control configuration related to ksqlDB, see Feature settings.

confluent.controlcenter.ksql.<ksql-cluster-name>.advertised.url

Comma-separated list of advertised URLs to access the ksqlDB cluster on Control Center (Legacy). Replace <ksql-cluster-name> with the name Control Center (Legacy) should use to identify this ksqlDB cluster. By default, this is set to the value specified in confluent.controlcenter.ksql.<ksql-cluster-name>.url. These hostnames must be reachable from any browser that will use the ksqlDB web interface in Control Center (Legacy).

For example, if ksqlDB is communicating over an internal DNS that is not externally resolvable or routeable (for example, if running in Docker for Mac), then the advertised URL must be set so that the browser can resolve the externally available DNS that ksqlDB is available at. For more information, see Integrate ksqlDB with Confluent Control Center (Legacy).

  • Type: list
  • Default: “”
  • Importance: low
confluent.controlcenter.ksql.<ksql-cluster-name>.url

Comma-separated list of the ksqlDB server hostnames and listener ports for the ksqlDB cluster specified by <ksql-cluster-name>. By default, this is empty. These hostnames must be reachable from the machine Control Center (Legacy) is installed on. For more information, see Integrate ksqlDB with Confluent Control Center (Legacy).

  • Type: list
  • Default: “”
  • Importance: low
confluent.controlcenter.ksql.advertised.url

Deprecated. The advertised URL to access the ksqlDB cluster on Control Center (Legacy). By default, this is set to the value specified in confluent.controlcenter.ksql.url.

  • Type: string
  • Default: “”
  • Importance: low
confluent.controlcenter.ksql.url

Deprecated. The ksqlDB server hostname and listener port. This is deprecated by confluent.controlcenter.ksql.<ksql-cluster-name>.url. If this deprecated configuration is supplied, then Control Center (Legacy) will ignore any named ksqlDB configurations.

  • Type: string
  • Default: “”
  • Importance: low

Internal Kafka Streams settings

Because Control Center (Legacy) reads and writes data to Kafka, you are allowed to change some producer and consumer configurations.

Caution

Changing these values is not recommended unless advised by Confluent Support.

Some examples of values used internally are given. These settings map 1:1 with producer/consumer configs used internally by Control Center (Legacy) and all use the prefix confluent.controlcenter.streams.{producer,consumer}..

confluent.controlcenter.streams.num.stream.threads

The number of threads to execute stream processing.

  • Type: int
  • Default: 12
  • Importance: low
confluent.controlcenter.streams.producer.compression.type

Compression type to use on internal topic production.

  • Type: string
  • Default: lz4
  • Importance: low
confluent.controlcenter.streams.producer.retries

Number of retries in case of production failure.

  • Type: int
  • Default: maximum integer (effectively infinite)
  • Importance: low
confluent.controlcenter.streams.producer.retry.backoff.ms

Time to wait before retrying in case of production failure.

  • Type: long
  • Default: 100
  • Importance: low
confluent.controlcenter.streams.retries
Deprecated. Number of times to retry client requests failing with transient errors. This is deprecated and replaced by confluent.controlcenter.streams.task.timeout.ms. Does not apply to producer retries, which are defined using the confluent.controlcenter.streams.producer.retries setting.
confluent.controlcenter.streams.task.timeout.ms

The maximum amount of time, in milliseconds, a task will wait due to internal errors and retry the task before an external error is raised. Replaces the deprecated confluent.controlcenter.streams.retries setting. If the timeout value set to 0 ms, a task would raise an external error when the first internal error occurs. For any timeout value larger than 0 ms, a task retries at least once before an error is raised.

  • Type: int
  • Default: 0
  • Importance: medium

Internal Command settings

The command topic is used to store internal configuration data for Control Center (Legacy).

Note

For multiple instances of Control Center (Legacy) using the same Kafka cluster for monitoring purposes, it may be helpful to use separate metrics and command topics (if each Control Center (Legacy) installation is monitoring different Kafka clusters).

The command topic reuses the defaults/overrides for Kafka Streams, but allows the following overrides.

confluent.controlcenter.command.topic

Topic used to store Control Center (Legacy) configuration.

  • Type: string
  • Default: _confluent-command
  • Importance: low
confluent.controlcenter.command.topic.replication

Replication factor for command topic.

Important

Reducing the replication value is not recommended, except in a development environment.

  • Type: int
  • Default: 3
  • Importance: low
confluent.controlcenter.command.topic.retention.ms

Maximum time in milliseconds that command data is stored in Kafka. For more information, see data retention.

  • Type: long
  • Default: 86,400,000 (1 day)
  • Importance: low

Consumer Group settings

If you find that the Consumer Group page is not returning data, you can change the timeout value for the page. The default value is 15 seconds (or 15000 milliseconds); try increasing the value to 30 seconds (30000 milliseconds) if you are having timeout issues.

confluent.controlcenter.consumer.metadata.timeout.ms

Time to wait when attempting to retrieve Consumer Group metadata.

  • Type: int
  • Default: 15,000
  • Importance: low