Configuration Reference for Cassandra Sink Connector for Confluent Platform

To use this connector, specify the name of the connector class in the connector.class configuration property.

connector.class=io.confluent.connect.cassandra.CassandraSinkConnector

Connector-specific configuration properties are described below.

Connection

cassandra.contact.points

The Cassandra hosts to connect to.

  • Type: list
  • Importance: high
  • Default Value: No default
cassandra.password

The password to connect to Cassandra with.

  • Type: password
  • Importance: high
  • Default Value: [hidden]
cassandra.local.datacenter

The local datacenter of the Cassandra contact points. Run the following CQL against a contact point to find it: SELECT data_center FROM system.local;.

  • Type: string
  • Importance: high
  • Default Value: No Default
cassandra.security

The authentication protocol to use against Cassandra. Supports plain text password authentication, Kerberos, or no authentication. cassandra.security.enabled was replaced with cassandra.security in version 2.0.0 of the connector.

  • Type: string
  • Importance: high
  • Default Value: true
  • Valid Values: [NONE, PASSWORD, KERBEROS]
cassandra.ssl.enabled

Flag to determine if SSL is enabled when connecting to Cassandra.

  • Type: boolean
  • Importance: high
  • Default Value: false
cassandra.username

The username to connect to Cassandra with.

  • Type: string
  • Importance: high
  • Default Value: cassandra
cassandra.port

The port the Cassandra hosts are listening on.

  • Type: Int
  • Importance: medium
  • Default Value: 9042
  • Valid Values: ValidPort{start=1025, end=65535}
cassandra.compression

Compression algorithm to use when connecting to Cassandra.

  • Type: string
  • Importance: low
  • Default Value: NONE
  • Valid Values: [NONE, SNAPPY, LZ4]

Keyspace

cassandra.keyspace

The keyspace to write to.

  • Type: string
  • Importance: high
cassandra.keyspace.create.enabled

Flag to determine if the keyspace should be created if it does not exist.

  • Type: boolean
  • Importance: high
  • Default Value: true

SSL

cassandra.ssl.truststore.password

Password to open the Java Truststore with.

  • Type: password
  • Importance: medium
  • Default Value: [hidden]
  • Valid Values: Empty String or Absolute path to a file that exists.
cassandra.ssl.truststore.path

Path to the Java Truststore.

  • Type: string
  • Importance: medium
  • Valid Values: Empty String or Absolute path to a file that exists.
cassandra.ssl.provider [DEPRECATED]
This configuration is no longer supported. Only Java’s SSL implementation is supported.

Kerberos

If Kerberos is enabled, the Connector assumes the krb5.conf files have been correctly configured and they point to a KDC which can issue tickets for Cassandra. The connector will refresh its TGT when it expires.

connect.cassandra.principal

The principal to use when connecting to Cassandra with Kerberos

  • Type: string
  • Importance: high
  • Default Value: “”
connect.cassandra.keytab

The path to the keytab file for the Cassandra connector principal. This keytab file should only be readable by the connector.

  • Type: string
  • Importance: high
  • Default Value: “”
  • Valid Values: Empty String or Absolute path to a file that exists.
cassandra.kerberos.sasl.protocol

The protocol that will be used, which should match the service portion of the Cassandra service principal (for example, if set to cassandra, the Cassandra service principal must be someuser/cassandra@realm).

  • Type: string
  • Importance: low
  • Default Value: cassandra

Table

cassandra.table.manage.enabled

Flag to determine if the connector should manage the table.

  • Type: boolean
  • Importance: high
  • Default Value: true
cassandra.table.create.caching

Caching setting to use. If N_ROWS is set, use cassandra.table.create.caching.rows.per.partition to pick the number of rows to cache per partition.

  • Type: string
  • Importance: medium
  • Default Value: NONE
  • Valid Values: ALL, KEYS_ONLY, ROWS_ONLY, NONE, N_ROWS
cassandra.table.create.caching.rows.per.partition

Number of rows per partition to cache. Ignored unless cassandra.table.create.caching is set to N_ROWS.

  • Type: Int
  • Importance: low
  • Default Value: 1000
cassandra.table.create.compression.algorithm

Compression algorithm to use when the table is created.

  • Type: string
  • Importance: medium
  • Default Value: NONE
  • Valid Values: [NONE, SNAPPY, LZ4, DEFLATE]
cassandra.offset.storage.table

The table within the Cassandra keyspace to store the offsets that have been read from Apache Kafka®. This is used to enable exactly once delivery to Cassandra.

  • Type: string
  • Importance: low
  • Default: kafka_connect_offsets

Write

cassandra.consistency.level

The requested consistency level to use when writing to Cassandra.

  • Type: string
  • Importance: high
  • Default Value: LOCAL_QUORUM
  • Valid Values: ANY, ONE, TWO, THREE, QUORUM, ALL, LOCAL_QUORUM, EACH_QUORUM, SERIAL, LOCAL_SERIAL, LOCAL_ONE
cassandra.deletes.enabled

Flag to determine if the connector should process deletes.

  • Type: boolean
  • Importance: high
  • Default Value: true
cassandra.write.mode

The type of statement to build when writing to Cassandra.

  • Type: string
  • Importance: high
  • Default Value: Insert
cassandra.execute.timeout.ms

The timeout for executing a Cassandra statement.

  • Type: long
  • Importance: low
  • Default Value: 30000
cassandra.ttl

The retention period for the data in Cassandra. After this interval elapses, Cassandra will remove these records.

  • Type: Int
  • Importance: medium
  • Default Value: null
cassandra.offset.storage.table.enable

If true, Kafka consumer offsets will be stored in the Cassandra table. If false, the connector will skip writing offset information into Cassandra (this might imply duplicate writes into Cassandra when a task restarts).

  • Type: boolean
  • Importance: medium
  • Default Value: True

Confluent Platform license

confluent.topic.bootstrap.servers

A list of host/port pairs to use for establishing the initial connection to the Kafka cluster used for licensing. All servers in the cluster will be discovered from the initial connection. 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. However, you may want more than one, in case a server is down.

  • Type: list
  • Importance: high
confluent.topic

Name of the Kafka topic used for Confluent Platform configuration, including licensing information.

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

The replication factor for the Kafka topic used for Confluent Platform configuration, including licensing information. This is used only if the topic does not already exist, and the default of 3 is appropriate for production use. If you are using a development environment with less than 3 brokers, you must set this to the number of brokers (often 1).

  • Type: int
  • Default: 3
  • Importance: low

Confluent license properties

You can put license-related properties in the connector configuration, or starting with Confluent Platform version 6.0, you can put license-related properties in the Connect worker configuration instead of in each connector configuration.

This connector is proprietary and requires a license. The license information is stored in the _confluent-command topic. If the broker requires SSL for connections, you must include the security-related confluent.topic.* properties as described below.

confluent.license

Confluent issues enterprise license keys to each subscriber. The license key is text that you can copy and paste as the value for confluent.license. A trial license allows using the connector for a 30-day trial period. A developer license allows using the connector indefinitely for single-broker development environments.

If you are a subscriber, contact Confluent Support for more information.

  • Type: string
  • Default: “”
  • Valid Values: Confluent Platform license
  • Importance: high
confluent.topic.ssl.truststore.location

The location of the trust store file.

  • Type: string
  • Default: null
  • Importance: high
confluent.topic.ssl.truststore.password

The password for the trust store file. If a password is not set access to the truststore is still available, but integrity checking is disabled.

  • Type: password
  • Default: null
  • Importance: high
confluent.topic.ssl.keystore.location

The location of the key store file. This is optional for client and can be used for two-way authentication for client.

  • Type: string
  • Default: null
  • Importance: high
confluent.topic.ssl.keystore.password

The store password for the key store file. This is optional for client and only needed if ssl.keystore.location is configured.

  • Type: password
  • Default: null
  • Importance: high
confluent.topic.ssl.key.password

The password of the private key in the key store file. This is optional for client.

  • Type: password
  • Default: null
  • Importance: high
confluent.topic.security.protocol

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

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

License topic configuration

A Confluent enterprise license is stored in the _confluent-command topic. This topic is created by default and contains the license that corresponds to the license key supplied through the confluent.license property. No public keys are stored in Kafka topics.

The following describes how the default _confluent-command topic is generated under different scenarios:

  • A 30-day trial license is automatically generated for the _confluent command topic if you do not add the confluent.license property or leave this property empty (for example, confluent.license=).
  • Adding a valid license key (for example, confluent.license=<valid-license-key>) adds a valid license in the _confluent-command topic.

Here is an example of the minimal properties for development and testing.

You can change the name of the _confluent-command topic using the confluent.topic property (for instance, if your environment has strict naming conventions). The example below shows this change and the configured Kafka bootstrap server.

confluent.topic=foo_confluent-command
confluent.topic.bootstrap.servers=localhost:9092

The example above shows the minimally required bootstrap server property that you can use for development and testing. For a production environment, you add the normal producer, consumer, and topic configuration properties to the connector properties, prefixed with confluent.topic..

License topic ACLs

The _confluent-command topic contains the license that corresponds to the license key supplied through the confluent.license property. It is created by default. Connectors that access this topic require the following ACLs configured:

  • CREATE and DESCRIBE on the resource cluster, if the connector needs to create the topic.

  • DESCRIBE, READ, and WRITE on the _confluent-command topic.

    Important

    You can also use DESCRIBE and READ without WRITE to restrict access to read-only for license topic ACLs. If a topic exists, the LicenseManager will not try to create the topic.

You can provide access either individually for each principal that will use the license or use a wildcard entry to allow all clients. The following examples show commands that you can use to configure ACLs for the resource cluster and _confluent-command topic.

  1. Set a CREATE and DESCRIBE ACL on the resource cluster:

    kafka-acls --bootstrap-server localhost:9092 --command-config adminclient-configs.conf \
--add --allow-principal User:<principal> \
--operation CREATE --operation DESCRIBE --cluster

  2. Set a DESCRIBE, READ, and WRITE ACL on the _confluent-command topic:

    kafka-acls --bootstrap-server localhost:9092 --command-config adminclient-configs.conf \
--add --allow-principal User:<principal> \
--operation DESCRIBE --operation READ --operation WRITE --topic _confluent-command

Override Default Configuration Properties

You can override the replication factor using confluent.topic.replication.factor. For example, when using a Kafka cluster as a destination with less than three brokers (for development and testing) you should set the confluent.topic.replication.factor property to 1.

You can override producer-specific properties by using the producer.override.* prefix (for source connectors) and consumer-specific properties by using the consumer.override.* prefix (for sink connectors).

You can use the defaults or customize the other properties as well. For example, the confluent.topic.client.id property defaults to the name of the connector with -licensing suffix. You can specify the configuration settings for brokers that require SSL or SASL for client connections using this prefix.

You cannot override the cleanup policy of a topic because the topic always has a single partition and is compacted. Also, do not specify serializers and deserializers using this prefix; they are ignored if added.