.. _controlcenter_configuration:

Configuration
=============

You can configure Confluent Control Center through a configuration file that is passed to Control Center on start.
Parameters are provided in the form of key/value pairs. Lines beginning with ``#`` are ignored.

Required Settings
-----------------

In almost all installations, you will want to configure these parameters:

``bootstrap.servers``
    A list of host/port pairs to use for establishing the initial connection to the 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 may 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

``zookeeper.connect``
    Specifies the ZooKeeper connection string in the form
    hostname:port where host and port are the host and port of a ZooKeeper server. To allow connecting
    through other ZooKeeper nodes when that ZooKeeper machine is down you can also specify multiple hosts
    in the form ``hostname1:port1,hostname2:port2,hostname3:port3,...``
    The server may also have a ZooKeeper chroot path as part of it's ZooKeeper connection string which puts
    its data under some path in the global ZooKeeper namespace. If so the consumer should use the same
    chroot path in its connection string. For example, for a chroot path of ``/chroot/path``, you would specify
    the connection string as ``hostname1:port1,hostname2:port2,hostname3:port3/chroot/path``.

  * Type: list
  * Default: "localhost:2181"
  * Importance: high

``confluent.controlcenter.connect.cluster``
    Comma-separated list of URLs for the Connect cluster

  * Type: string
  * Default: "localhost:8083"
  * Importance: high

``confluent.controlcenter.connect.zookeeper.connect``
    Specifies the ZooKeeper connection string for the Kafka cluster backing the Connect cluster

* Type: string
* Default: the value of ``zookeeper.connect``
* Importance: high

``confluent.controlcenter.license``
    Confluent will issue a license key to each subscriber, allowing the subscriber to unlock the full functionality
    of Control Center. The license key will be a short snippet of text that you can copy and paste. Paste this value
    into the license key. If you do not provide a license key, Control Center will stop working after 30 days. If you
    are a subscriber, please contact Confluent Support for more information.

  * Type: string
  * Default: None
  * Importance: high

Optional Settings
-----------------

We allow you to change some other parameters that change how Control Center 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.

``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.

  * Type: list
  * Default: "http://0.0.0.0:9021"
  * Importance: high

``confluent.controlcenter.data.dir``
    Location for ControlCenter specific data

  * Type: path
  * Default: "/tmp/confluent/control-center"
  * Importance: high

``confluent.controlcenter.streams.consumer.auto.offset.reset``
    Controls default consumer behavior when no previously committed offsets are present.
    Set this to "latest" if you do not want to process any historical stream monitoring
    data (which can take some time) on initial start-up. Note that once any offsets are
    committed, this setting has no effect on subsequent restarts.

  * Type: string
  * Default: "earliest"
  * Importance: high

``confluent.controlcenter.id``
    Identifier used as a prefix so that multiple instances of Control Center can co-exist.

  * Type: string
  * Default: 1
  * Importance: low

``confluent.controlcenter.command.topic``
    Topic used to store Control Center configuration

  * Type: string
  * Default: "_confluent-command"
  * Importance: low


``confluent.monitoring.interceptor.topic``
    The durable topic that acts as the durable log for the data

  * Type: string
  * Default: "_confluent-monitoring"
  * Importance: low

``confluent.controlcenter.name``
    Control Center Name

  * Type: string
  * Default: "_confluent-controlcenter-3-1-0"
  * Importance: low

``confluent.controlcenter.internal.topics.partitions``
    Number of partitions used internally by Control Center.

  * Type: integer
  * Default: 4
  * Importance: low

``confluent.controlcenter.internal.topics.replication``
    Replication factor used internally by Control Center.

  * Type: integer
  * Default: 3
  * Importance: low

``confluent.controlcenter.internal.topics.retention.ms``
    Maximum time in milliseconds that internal data is stored in Kafka.

  * Type: long
  * Default: 86400000
  * 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: 134217728
  * Importance: low

``confluent.monitoring.interceptor.topic.partitions``
    Number of partitions for interceptor metrics topic.

  * Type: integer
  * Default: 12
  * Importance: low

``confluent.monitoring.interceptor.topic.replication``
    Replication factor for interceptor metrics topic.

  * Type: integer
  * Default: 3
  * Importance: low

``confluent.monitoring.interceptor.topic.retention.ms``
    Maximum time that interceptor data is stored in Kafka.

  * Type: long
  * Default: None
  * Importance: low

``confluent.controlcenter.connect.timeout``
    Timeout in milliseconds for calls to connect cluster

  * Type: long
  * Default: 15000
  * Importance: low

.. _ui_authentication_settings:

UI Authentication Settings
--------------------------

``confluent.controlcenter.rest.authentication.method``
    Authentication method to use. One of [NONE, BASIC].

  * Type: string
  * Default: NONE
  * Importance: low

``confluent.controlcenter.rest.authentication.realm``
    Realm to be used by Control Center when authenticating.

  * Type: string
  * Default: ""
  * Importance: low

``confluent.controlcenter.rest.authentication.roles``
    Roles that are authenticated to access Control Center.

  * Type: string
  * Default: "*"
  * Importance: low

.. _email_settings:

Email Settings
--------------

``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: integer
  * Default: 587
  * Importance: low

``confluent.controlcenter.mail.from``
    The 'from' address for emails sent from Control Center.

  * Type: string
  * Default: c3@confluent.io
  * Importance: low

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

  * Type: string
  * Importance: low

``confluent.controlcenter.mail.ssl.checkserveridentity``
    Forces validation of server's certificate when using STARTTLS or SSL.

  * Type: boolean
  * Default: false
  * Importance: low

``confluent.controlcenter.mail.starttls.required``
    Forces using STARTTLS.

  * Type: boolean
  * Default: false
  * Importance: low

``confluent.controlcenter.mail.username``
    Username for username/pw authentication. If this value is not set there will be no authentication with your smtp server.

  * Type: string
  * Importance: low

``confluent.controlcenter.mail.password``
    Password for username/pw authentication.

  * Type: string
  * Importance: low

.. _kafka_encryption_authentication_authorization_settings:

Kafka Encryption, Authentication, Authorization Settings
--------------------------------------------------------

Security parameters must be set on both producers and consumers. The prefix for producer
settings is ``confluent.controlcenter.streams.producer`` and the prefix for consumer
settings is ``confluent.controlcenter.streams.consumer``.

``confluent.controlcenter.streams.{producer,consumer}.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.{producer,consumer}.ssl.keystore.location``
    The location of the key store file.

  * Type: string
  * Default: None
  * Importance: low

``confluent.controlcenter.streams.{producer,consumer}.ssl.keystore.password``
    The store password for the key store file.

  * Type: string
  * Default: None
  * Importance: low

``confluent.controlcenter.streams.{producer,consumer}.ssl.key.password``
    The password of the private key in the key store file.

  * Type: string
  * Default: None
  * Importance: low

``confluent.controlcenter.streams.{producer,consumer}.ssl.truststore.location``
    The location of the trust store file.

  * Type: string
  * Default: None
  * Importance: low

``confluent.controlcenter.streams.{producer,consumer}.ssl.truststore.location``
    The location of the trust store file.

  * Type: string
  * Default: None
  * Importance: low

``confluent.controlcenter.streams.{producer,consumer}.ssl.truststore.password``
    The password for the trust store file.

  * Type: string
  * Default: None
  * Importance: low

``confluent.controlcenter.streams.{producer,consumer}.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.{producer,consumer}.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: GSSAPI
  * Importance: low

.. _https_settings:

HTTPS Settings
--------------

If you secure web access to Control Center with SSL, you may also need to configure the following parameters.

``confluent.controlcenter.rest.ssl.keystore.location``
  Used for https. Location of the keystore file to use for 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 trust store. 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 trust store 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 trust store file.

  * Type: string
  * Default: "JKS"
  * Importance: medium

``confluent.controlcenter.rest.ssl.protocol``
  Used for https. The SSL protocol used to generate the SslContextFactory.

  * Type: string
  * Default: "TLS"
  * Importance: medium

``confluent.controlcenter.rest.ssl.provider``
  Used for https. The SSL security provider name. Leave blank to use Jetty's default.

  * Type: string
  * Default: "" (Jetty's default)
  * Importance: medium

``confluent.controlcenter.rest.ssl.client.auth``
  Used for https. Whether or not to require the https client to authenticate via the server's trust store.

  * Type: boolean
  * Default: false
  * Importance: medium

``confluent.controlcenter.rest.ssl.enabled.protocols``
  Used for https. The list of protocols enabled for SSL connections. Comma-separated list. Leave blank to use Jetty's defaults.

  * Type: list
  * Default: "" (Jetty's default)
  * Importance: medium

``confluent.controlcenter.rest.ssl.keymanager.algorithm``
  Used for https. The algorithm used by the key manager factory for SSL connections. Leave blank to use Jetty's default.

  * Type: string
  * Default: "" (Jetty's default)
  * Importance: low

``confluent.controlcenter.rest.ssl.trustmanager.algorithm``
  Used for https. The algorithm used by the trust manager factory for SSL connections. Leave blank to use Jetty's default.

  * Type: string
  * Default: "" (Jetty's default)
  * Importance: low

``confluent.controlcenter.rest.ssl.cipher.suites``
  Used for https. A list of SSL cipher suites. Comma-separated list. Leave blank to use Jetty's defaults.

  * Type: list
  * Default: "" (Jetty's 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 Jetty's default.

  * Type: string
  * Default: "" (Jetty's default)
  * Importance: low

Internal Kafka Streams Settings
-------------------------------

Because Control Center reads and writes data to Kafka, we also allow you to change some producer and consumer configurations. We do not recommend changing these values 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 Confluent Control Center 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: integer
  * Default: 8
  * Importance: low

``confluent.controlcenter.streams.consumer.session.timeout.ms``
    The timeout used to detect a consumer failure

  * Type: integer
  * Default: 275000
  * Importance: low

``confluent.controlcenter.streams.consumer.request.timeout.ms``
    The maximum amount of time the client will wait for the response of a request

  * Type: integer
  * Default: 285000
  * Importance: low

``confluent.controlcenter.streams.producer.retries``
    Number of retries in case of production failure

  * Type: integer
  * 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.producer.compression.type``
    Compression type to use on internal topic production

  * Type: string
  * Default: lz4
  * Importance: low

Internal Command Settings
-------------------------

The Command topic will reuse the defaults/overrides for streams, but allows the following overrides.

``confluent.controlcenter.command.topic.replication``
    Replication factor for command topic

  * Type: integer
  * Default: 3
  * Importance: low