DataStax Sink Connector for Confluent Cloud

The fully managed DataStax Sink connector for Confluent Cloud streams records from Apache Kafka® topics into Apache Cassandra, DataStax Enterprise (DSE), or DataStax Astra DB tables, without managing any connector infrastructure.

If you require private networking for fully managed connectors, make sure to set up the proper networking beforehand. For more information, see Manage Networking for Confluent Cloud Connectors.

Features

The DataStax Sink connector offers the following features:

Multiple targets: Writes to Apache Cassandra 2.1 and later, DSE 4.7 and later, or DataStax Astra DB, using the same connector configuration.
Multiple input formats: Supports AVRO, JSON_SR (JSON Schema), PROTOBUF, JSON (schemaless), or BYTES input data formats. Schema Registry must be enabled to use a Schema Registry-based format such as AVRO, JSON_SR, or PROTOBUF.
Declarative topic-to-table mapping: Maps record fields to table columns using the connector’s mapping domain-specific language (DSL), including fan-out from a single topic to multiple tables and consuming from multiple topics in one connector.
Row-level TTL and writetime overrides: Sets a row’s time-to-live (TTL) and write timestamp from values in the Kafka record, so data ages out and orders correctly without a separate cleanup job.
Flexible security and networking: Connects using TLS, PLAIN, or mutual TLS (mTLS) authentication, and supports private networking options where available on your cluster.

For more information and examples to use with the Confluent Cloud API for Connect, see the Confluent Cloud API for Connect Usage Examples section.

Limitations

For connector limitations, see DataStax Sink Connector.
If you plan to use one or more Single Message Transformations (SMTs), see SMT Limitations.

If you plan to use one or more Custom SMTs, see Custom SMT limitations.

Quick start

Select the connector and configure it to stream Kafka events into Cassandra, DSE, or Astra DB tables.

Prerequisites

Authorized access to a Confluent Cloud cluster on Amazon Web Services (AWS), Microsoft Azure (Azure), or Google Cloud.
The Confluent CLI installed and configured for the cluster. For more information, see Install the Confluent CLI.
Schema Registry must be enabled to use a Schema Registry-based format, such as AVRO, JSON_SR (JSON Schema), or PROTOBUF. For more information, see Limits for Fully Managed Connectors for Confluent Cloud.
Access to an Apache Cassandra, DSE, or DataStax Astra DB target, with the destination keyspace, tables, and any user-defined types (UDTs) or frozen collections already created. The connector does not create these automatically.
Database credentials with write access to the target keyspace. For Astra DB, a Secure Connect Bundle (SCB) downloaded from the Astra console.
For networking considerations, see Networking and DNS. To use a set of public egress IP addresses, see Public Egress IP Addresses for Confluent Cloud Connectors.

Kafka cluster credentials. The following lists the different ways you can provide credentials.
- Enter an existing service account resource ID.
- Create a Confluent Cloud service account for the connector. Make sure to review the ACL entries required in the service account documentation. Some connectors have specific ACL requirements.
- Create a Confluent Cloud API key and secret. To create a key and secret, you can use confluent api-key create or you can autogenerate the API key and secret directly in the Cloud Console when setting up the connector.

Using the Confluent Cloud Console

Step 1: Launch your Confluent Cloud cluster

To create and launch a Kafka cluster in Confluent Cloud, see Create a kafka cluster in Confluent Cloud.

Step 2: Add a connector

In the left navigation menu, click Connectors. If you already have connectors in your cluster, click + Add connector.

Step 3: Select your connector

Click the DataStax Sink connector card.

Step 4: Enter the connector details

Before configuring the connector settings, ensure that you complete all prerequisites.

Note

An asterisk ( * ) designates a required entry.

At the Add DataStax Sink Connector screen, complete the following:

Topic selection

If you’ve already populated your Kafka topics, select the topics you want to connect from the Topics list.

To create a new topic, click +Add new topic.

Kafka access

Select the way you want to provide Kafka Cluster credentials. You can choose one of the following options:
- My account: This setting allows your connector to globally access everything that you have access to. With a user account, the connector uses an API key and secret to access the Kafka cluster. This option is not recommended for production.
- Service account: This setting limits the access for your connector by using a service account. This option is recommended for production.
- Use an existing API key: This setting allows you to specify an API key and a secret pair. You can use an existing pair or create a new one. This method is not recommended for production environments.
Note

Freight clusters support only service accounts for Kafka authentication.
Click Continue.

Authentication

Choose the Deployment type, either Apache Cassandra or DSE or DataStax Astra, and configure the matching connection and authentication properties:

How should we connect to Cassandra / DSE / Astra?
- Deployment type: The database you are connecting to. Choose Apache Cassandra or DSE to connect through contact points (optionally with SSL/TLS), or DataStax Astra to connect through an uploaded Secure Connect Bundle. The two modes are mutually exclusive and the connector cannot use both at once. For CLI or Terraform provisioning, set this explicitly.
- Cassandra/DSE contact points: Comma-separated host names or IPs of the Cassandra or DSE cluster contact points. Used only for the Apache Cassandra or DSE deployment type. Leave this empty for Astra and use the Secure Connect Bundle instead.
- Native transport port: Cassandra/DSE native transport port (ignored for Astra).
- Local datacenter: Name of the local datacenter the driver should treat as local (commonly dc1). Required for the Apache Cassandra or DSE deployment type. Must not be set for Astra.
- Astra Secure Connect Bundle: DataStax Astra DB Secure Connect Bundle (SCB). Required for the DataStax Astra deployment type, and mutually exclusive with contact points, local datacenter, or SSL settings. Upload the SCB zip file. For REST API usage base64-encode it and prefix with data:application/octet-stream;base64,.
Authentication
- Authentication provider: Authentication provider to the database. None for no authentication, PLAIN for username/password (also used for LDAP and for Astra token authentication).
- Username: Database username for PLAIN authentication. For Astra token authentication use the literal token.
- Password: Database password for PLAIN authentication. For Astra token authentication use the AstraCS:... token.
Security (SSL/TLS)
- SSL/TLS provider: SSL/TLS engine used for the connection to Cassandra/DSE. None disables SSL. JDK uses the JSSE keystore/truststore (JKS). OpenSSL uses PEM certificate and private key files. Only applicable to the Apache Cassandra or DSE deployment type — Astra’s TLS material is carried inside the Secure Connect Bundle.
- Validate server hostname: Whether to validate the database node hostnames against the certificate when SSL is enabled.
- Truststore file: Truststore file (JKS) containing the CA certificate(s) that sign the database server certificates. Upload the file. For REST API usage base64-encode it and prefix with data:application/octet-stream;base64,.
- Truststore password: Password protecting the truststore file. Leave empty if the truststore has no password.
- Keystore file (mTLS): Keystore file (JKS) holding the client certificate and private key for mutual TLS (client authentication). Only needed when the database requires client certificates. Upload the file. For REST API usage base64-encode it and prefix with data:application/octet-stream;base64,.
- Keystore password: Password protecting the keystore file (leave empty if the keystore has no password).
- Cipher suites: Optional comma-separated list of TLS cipher suites to enable. Leave empty to use the JVM defaults.
Click Continue.

Configuration

Note

Configuration properties that are not shown in the Cloud Console use the default values. For all property values and definitions, see Configuration Properties.

Input Kafka record value format: Sets the input Kafka record value format. Valid entries are AVRO, JSON_SR, PROTOBUF, JSON, or BYTES. Note that you need to have Confluent Cloud Schema Registry configured if using a schema-based message format like AVRO, JSON_SR, and PROTOBUF.

Table mapping

Topic-to-table field mapping: JSON object mapping each <topic>.<keyspace>.<table> to its field-to-column mapping, for example {"orders.ecom.orders":"id=value.id, amount=value.amount"}. Use key.* to reference record-key fields (primary-key columns) and value.* for record-value fields. Each entry materializes to the engine key topic.<topic>.<keyspace>.<table>.mapping. A single topic can map to multiple tables (fan-out) by adding multiple entries.

Data decryption

Enable Client-Side Field Level Encryption for data decryption. Specify a Service Account to access the Schema Registry and associated encryption rules or keys with that schema. Select the connector behavior (ERROR or NONE) on data decryption failure. If set to ERROR, the connector fails and writes the encrypted data in the DLQ. If set to NONE, the connector writes the encrypted data in the target system without decryption. For more information on CSFLE or CSPE setup, see Manage encryption for connectors.

Show advanced configurations

Schema context: Select a schema context to use for this connector, if using a schema-based data format. This property defaults to the Default context, which configures the connector to use the default schema set up for Schema Registry in your Confluent Cloud environment. A schema context allows you to use separate schemas (like schema sub-registries) tied to topics in different Kafka clusters that share the same Schema Registry environment. For example, if you select a non-default context, a Source connector uses only that schema context to register a schema and a Sink connector uses only that schema context to read from. For more information about setting up a schema context, see What are schema contexts and when should you use them?.
Input Kafka record key format: Sets the input Kafka record key format. Valid entries are AVRO, BYTES, JSON, JSON_SR, PROTOBUF, or STRING. Note that you need to have Confluent Cloud Schema Registry configured if using a schema-based message format like AVRO, JSON_SR, and PROTOBUF.

Additional Configs

Value Converter Replace Null With Default: Specifies whether to replace fields that have a default value and that are null to the default value. When set to true, the connector uses the default value; otherwise, it uses null. Applies to the JSON converter.
Value Converter Schema ID Deserializer: Sets the class name of the schema ID deserializer for values. The deserializer reads schema IDs from message headers.
Value Converter Reference Subject Name Strategy: Sets the subject reference name strategy for values. Valid entries are DefaultReferenceSubjectNameStrategy or QualifiedReferenceSubjectNameStrategy. You can use this strategy only with PROTOBUF format; the default strategy is DefaultReferenceSubjectNameStrategy.
Schema ID For Value Converter: Sets the schema ID to use for deserialization when using ConfigSchemaIdDeserializer. This lets you specify a fixed schema ID for deserializing message values. This property is applicable only when value.converter.value.schema.id.deserializer is set to ConfigSchemaIdDeserializer.
Value Converter Schemas Enable: Includes schema within each of the serialized values. Input messages must contain schema and payload fields and must not contain additional fields. For plain JSON data, set this to false. Applies to the JSON converter.
Errors Tolerance: Use this property to configure the connector’s error handling behavior.

Warning

Use this property with caution for sink connectors, as it can lead to data loss. If you set this property to all, the connector does not fail on errant records, but logs them (and sends to DLQ for sink connectors) and continues processing. If you set this property to none, the connector task fails on errant records.
Value Converter Ignore Default For Nullables: When set to true, this property ensures that the corresponding record in Kafka is null, instead of showing the default column value. Applies to the AVRO, PROTOBUF, and JSON_SR converters.
Key Converter Schema ID Deserializer: Sets the class name of the schema ID deserializer for keys. The deserializer reads schema IDs from message headers.
Value Converter Decimal Format: Specifies the JSON or JSON_SR serialization format for Connect DECIMAL logical type values with two allowed literals: BASE64 to serialize DECIMAL logical types as base64 encoded binary data, and NUMERIC to serialize DECIMAL logical type values in JSON or JSON_SR as a number representing the decimal value.
Schema GUID For Key Converter: Sets the schema GUID to use for deserialization when using ConfigSchemaIdDeserializer. This lets you specify a fixed schema GUID for deserializing message keys. This property is applicable only when key.converter.key.schema.id.deserializer is set to ConfigSchemaIdDeserializer.
Schema GUID For Value Converter: Sets the schema GUID to use for deserialization when using ConfigSchemaIdDeserializer. This lets you specify a fixed schema GUID for deserializing message values. This property is applicable only when value.converter.value.schema.id.deserializer is set to ConfigSchemaIdDeserializer.
Value Converter Connect Meta Data: Enables the Connect converter to add its metadata to the output schema. Applies to Avro converters.
Value Converter Value Subject Name Strategy: Determines how to construct the subject name under which the value schema is registered with Schema Registry.
Key Converter Key Subject Name Strategy: Determines how to construct the subject name for key schema registration.
Schema ID For Key Converter: Sets the schema ID to use for deserialization when using ConfigSchemaIdDeserializer. This lets you specify a fixed schema ID for deserializing message keys. This property is applicable only when key.converter.key.schema.id.deserializer is set to ConfigSchemaIdDeserializer.

Auto-restart policy

Enable Connector Auto-restart: Enables the auto-restart behavior of the connector and its task in the event of user-actionable errors. Defaults to true, enabling the connector to automatically restart in case of user-actionable errors. Set this property to false to disable auto-restart for failed connectors. If disabled, you must manually restart the connector.

Consumer configuration

Max poll interval(ms): Sets the maximum delay between subsequent consume requests to Kafka. Use this property to improve connector performance in cases when the connector cannot send records to the sink system. The default is 300,000 milliseconds (5 minutes).
Max poll records: Sets the maximum number of records to consume from Kafka in a single request. Use this property to improve connector performance in cases when the connector cannot send records to the sink system. The default is 500 records.

Table mapping

Per-table / per-topic overrides: Optional JSON object of per-table and per-topic overrides. Per-table keys are <topic>.<keyspace>.<table>.<setting> where <setting> is one of consistencyLevel, ttl, ttlTimeUnit, timestampTimeUnit, nullToUnset, deletesEnabled, or query. Per-topic codec keys are <topic>.codec.<setting> where <setting> is one of locale, timeZone, timestamp, date, time, or unit. Example: {"orders.ecom.orders.consistencyLevel":"LOCAL_QUORUM", "orders.ecom.orders.ttl":"3600", "orders.codec.timeZone":"UTC"}. Each entry materializes to the engine key topic.<entry-key>.

Connection tuning

Max concurrent requests: Maximum number of requests to send to the database at once.
Max records per batch: Maximum number of records sent in a single UNLOGGED batch request.
Query execution timeout (s): CQL statement execution timeout, in seconds.
Local connection pool size: Number of connections the driver maintains to each node in the local datacenter.
Protocol compression: Compression algorithm to use for requests to the database server.

Transforms

Single Message Transformations: To add a new SMT, see Add transforms. For more information about unsupported SMTs, see Unsupported transformations.

For all property values and definitions, see Configuration Properties.

Click Continue.

Sizing

Based on the number of topic partitions you select, Confluent Cloud recommends a number of tasks.

To change the number of recommended tasks, enter the number of tasks for the connector to use in the Tasks field.
Click Continue.

Review and Launch

Verify the connection details.
Click Launch.

The status for the connector should go from Provisioning to Running.

Step 5: Check the target database

After the connector is running, verify that records are populating the mapped tables in your Cassandra, DSE, or Astra DB keyspace.

For more information and examples to use with the Confluent Cloud API for Connect, see the Confluent Cloud API for Connect Usage Examples section.

Tip

When you launch a connector, a Dead Letter Queue topic is automatically created. For more information, see View Connector Dead Letter Queue Errors in Confluent Cloud.

Using the Confluent CLI

Complete the following steps to set up and run the connector using the Confluent CLI.

Note

Make sure you have all your prerequisites completed.

Step 1: List the available connectors

Enter the following command to list available connectors:

confluent connect plugin list

Step 2: List the connector configuration properties

Enter the following command to show the connector configuration properties:

confluent connect plugin describe <connector-plugin-name>

The command output shows the required and optional configuration properties.

Step 3: Create the connector configuration file

Create a JSON file that contains the connector configuration properties. The following example shows the required properties for connecting to Apache Cassandra or DSE.

{
  "connector.class": "DataStaxSink",
  "name": "DataStaxSinkConnector_0",
  "topics": "orders",
  "kafka.auth.mode": "KAFKA_API_KEY",
  "kafka.api.key": "<my-kafka-api-key>",
  "kafka.api.secret": "<my-kafka-api-secret>",
  "input.data.format": "AVRO",
  "deployment.type": "Apache Cassandra or DSE",
  "contactPoints": "<cassandra-host-1>,<cassandra-host-2>",
  "port": "9042",
  "loadBalancing.localDc": "<local-datacenter-name>",
  "auth.provider": "PLAIN",
  "auth.username": "<database-username>",
  "auth.password": "<database-password>",
  "mapping.map": "{\"orders.ecom.orders\":\"id=value.id, amount=value.amount\"}",
  "tasks.max": "1"
}

To connect to DataStax Astra DB instead, remove the contactPoints, port, and loadBalancing.localDc properties and add the following properties:

{
  "deployment.type": "DataStax Astra",
  "cloud.secureConnectBundle": "<base64-encoded-secure-connect-bundle>",
  "auth.provider": "PLAIN",
  "auth.username": "token",
  "auth.password": "<astra-application-token>"
}

Note the following property definitions:

"connector.class": Identifies the connector plugin name.
"name": Sets a name for your new connector.
"topics": Identifies the topic name or a comma-separated list of topic names.
"input.data.format": Sets the input Kafka record value format. Valid entries are AVRO, JSON_SR, PROTOBUF, JSON, or BYTES. You must have Confluent Cloud Schema Registry configured if using a schema-based message format such as AVRO, JSON_SR, or PROTOBUF.

"kafka.auth.mode": Identifies the connector authentication mode you want to use. There are two options: SERVICE_ACCOUNT or KAFKA_API_KEY (the default). To use an API key and secret, specify the configuration properties kafka.api.key and kafka.api.secret, as shown in the example configuration (above). To use a service account, specify the Resource ID in the property kafka.service.account.id=<service-account-resource-ID>. To list the available service account resource IDs, use the following command:
```
confluent iam service-account list
```
For example:
```
confluent iam service-account list

   Id     | Resource ID |       Name        |    Description
+---------+-------------+-------------------+-------------------
   123456 | sa-l1r23m   | sa-1              | Service account 1
   789101 | sa-l4d56p   | sa-2              | Service account 2
```

"deployment.type": Sets which database you are connecting to. Use Apache Cassandra or DSE to connect using contact points, or DataStax Astra to connect using an uploaded SCB.
"contactPoints": Comma-separated host names or IP addresses of the Cassandra or DSE cluster contact points. Applies only when deployment.type is set to Apache Cassandra or DSE.
"loadBalancing.localDc": The name of the local datacenter the driver treats as local, for example dc1. Required when deployment.type is set to Apache Cassandra or DSE.
"cloud.secureConnectBundle": The base64-encoded Astra DB SCB. Required when deployment.type is set to DataStax Astra.
"mapping.map": A JSON object that maps each <topic>.<keyspace>.<table> to its field-to-column mapping. A single topic can map to multiple tables by adding multiple entries. For all mapping syntax and per-table override properties, see Configuration Properties.

Note

To enable CSFLE or CSPE for data encryption, specify the following properties:

csfle.enabled: Flag to indicate whether the connector honors CSFLE or CSPE rules.
sr.service.account.id: A Service Account to access the Schema Registry and associated encryption rules or keys with that schema.
csfle.onFailure: Configures the connector behavior (ERROR or NONE) on data decryption failure. If set to ERROR, the connector fails and writes the encrypted data in the DLQ. If set to NONE, the connector writes the encrypted data in the target system without decryption.

When using CSFLE or CSPE with connectors that route failed messages to a Dead Letter Queue (DLQ), be aware that data sent to the DLQ is written in unencrypted plaintext. This poses a significant security risk as sensitive data that should be encrypted may be exposed in the DLQ.

Do not use DLQ with CSFLE or CSPE in the current version. If you need error handling for CSFLE- or CSPE-enabled data, use alternative approaches such as:

Setting the connector behavior to ERROR to throw exceptions instead of routing to DLQ
Implementing custom error handling in your applications
Using NONE to pass encrypted data through without decryption

For more information on CSFLE or CSPE setup, see Manage encryption for connectors.

SMTs: For details about adding SMTs using the Confluent CLI, see the Single Message Transformations documentation.

For all configuration property values and descriptions, see Configuration Properties.

Step 4: Load the configuration file and create the connector

Enter the following command to load the configuration and start the connector:

confluent connect cluster create --config-file <file-name>.json

For example:

confluent connect cluster create --config-file datastax-sink-config.json

Example output:

Created connector DataStaxSinkConnector_0 lcc-ix4dl

Step 5: Check the connector status

Enter the following command to check the connector status:

confluent connect cluster list

Example output:

ID          |          Name              | Status  | Type
+-----------+----------------------------+---------+------+
lcc-ix4dl   | DataStaxSinkConnector_0    | RUNNING | sink

Step 6: Check the target database

After the connector is running, verify that records are populating the mapped tables in your Cassandra, DSE, or Astra DB keyspace.

For more information and examples to use with the Confluent Cloud API for Connect, see the Confluent Cloud API for Connect Usage Examples section.

Tip

When you launch a connector, a Dead Letter Queue topic is automatically created. For more information, see View Connector Dead Letter Queue Errors in Confluent Cloud.

Configuration Properties

Use the following configuration properties with the fully managed connector.

How should we connect to your data?

name

Sets a name for your connector.

Type: string
Valid Values: A string at most 64 characters long
Importance: high

Schema Config

schema.context.name

Add a schema context name. A schema context represents an independent scope in Schema Registry. It is a separate sub-schema tied to topics in different Kafka clusters that share the same Schema Registry instance. If not used, the connector uses the default schema configured for Schema Registry in your Confluent Cloud environment.

Type: string
Default: default
Importance: medium

Input messages

input.data.format

Sets the input Kafka record value format. Valid entries are AVRO, JSON_SR, PROTOBUF, JSON or BYTES. Note that you need to have Confluent Cloud Schema Registry configured if using a schema-based message format like AVRO, JSON_SR, and PROTOBUF.

Type: string
Default: JSON
Importance: high

input.key.format

Sets the input Kafka record key format. Valid entries are AVRO, BYTES, JSON, JSON_SR, PROTOBUF, or STRING. Note that you need to have Confluent Cloud Schema Registry configured if using a schema-based message format like AVRO, JSON_SR, and PROTOBUF

Type: string
Default: JSON
Valid Values: AVRO, BYTES, JSON, JSON_SR, PROTOBUF, STRING
Importance: high

Kafka Cluster credentials

kafka.auth.mode

Kafka Authentication mode. It can be one of KAFKA_API_KEY or SERVICE_ACCOUNT. It defaults to KAFKA_API_KEY mode, whenever possible.

Type: string
Valid Values: SERVICE_ACCOUNT, KAFKA_API_KEY
Importance: high

kafka.api.key

Kafka API Key. Required when kafka.auth.mode==KAFKA_API_KEY.

Type: password
Importance: high

kafka.service.account.id

The Service Account that will be used to generate the API keys to communicate with Kafka Cluster.

Type: string
Importance: high

kafka.api.secret

Secret associated with Kafka API key. Required when kafka.auth.mode==KAFKA_API_KEY.

Type: password
Importance: high

Which topics do you want to get data from?

topics.regex

A regular expression that matches the names of the topics to consume from. This is useful when you want to consume from multiple topics that match a certain pattern without having to list them all individually.

Type: string
Importance: low

topics

Identifies the topic name or a comma-separated list of topic names.

Type: list
Importance: high

errors.deadletterqueue.topic.name

The name of the topic to be used as the dead letter queue (DLQ) for messages that result in an error when processed by this sink connector, or its transformations or converters. Defaults to ‘dlq-${connector}’ if not set. The DLQ topic will be created automatically if it does not exist. You can provide ${connector} in the value to use it as a placeholder for the logical cluster ID.

Type: string
Default: dlq-${connector}
Importance: low

How should we connect to Cassandra / DSE / Astra?

deployment.type

Which database you are connecting to. Choose Apache Cassandra or DSE to connect via contact points (optionally with SSL/TLS), or DataStax Astra to connect via an uploaded Secure Connect Bundle. The two modes are mutually exclusive — the connector cannot use both at once. For CLI/Terraform provisioning, set this explicitly.

Type: string
Default: Apache Cassandra or DSE
Valid Values: Apache Cassandra or DSE, DataStax Astra
Importance: high

contactPoints

Comma-separated host names or IPs of the Cassandra/DSE cluster contact points. Used only for the Apache Cassandra or DSE deployment type; leave empty for Astra (use the Secure Connect Bundle instead).

Type: string
Default: “”
Importance: high

port

Cassandra/DSE native transport port (ignored for Astra).

Type: int
Default: 9042
Valid Values: [1,…]
Importance: low

loadBalancing.localDc

Name of the local datacenter the driver should treat as local (commonly dc1). Required for the Apache Cassandra or DSE deployment type; must not be set for Astra.

Type: string
Default: “”
Importance: medium

cloud.secureConnectBundle

DataStax Astra DB Secure Connect Bundle (SCB). Required for the DataStax Astra deployment type, and mutually exclusive with contact points / local datacenter / SSL settings. Upload the SCB zip file; for REST API usage base64-encode it and prefix with data:application/octet-stream;base64,.

Type: password
Importance: high

Authentication

auth.provider

Authentication provider to the database. None for no auth, PLAIN for username/password (also used for LDAP and for Astra token auth).

Type: string
Default: None
Valid Values: None, PLAIN
Importance: medium

auth.username

Database username (for PLAIN auth; for Astra token auth use the literal token).

Type: string
Default: “”
Importance: medium

auth.password

Database password (for PLAIN auth; for Astra token auth use the AstraCS:... token).

Type: password
Importance: medium

Security (SSL/TLS)

ssl.provider

SSL/TLS engine used for the connection to Cassandra/DSE. None disables SSL. JDK uses the JSSE keystore/truststore (JKS). Only applicable to the Apache Cassandra or DSE deployment type — Astra’s TLS material is carried inside the Secure Connect Bundle.

Type: string
Default: None
Valid Values: JDK, None
Importance: medium

ssl.hostnameValidation

Whether to validate the database node hostnames against the certificate when SSL is enabled.

Type: boolean
Default: true
Importance: medium

ssl.truststore.path

Truststore file (JKS) containing the CA certificate(s) that sign the database server certificates. Upload the file; for REST API usage base64-encode it and prefix with data:application/octet-stream;base64,.

Type: password
Importance: medium

ssl.truststore.password

Password protecting the truststore file (leave empty if the truststore has no password).

Type: password
Importance: medium

ssl.keystore.path

Keystore file (JKS) holding the client certificate + private key for mutual TLS (client authentication). Only needed when the database requires client certificates. Upload the file; for REST API usage base64-encode it and prefix with data:application/octet-stream;base64,.

Type: password
Importance: medium

ssl.keystore.password

Password protecting the keystore file (leave empty if the keystore has no password).

Type: password
Importance: medium

ssl.cipherSuites

Optional comma-separated list of TLS cipher suites to enable. Leave empty to use the JVM defaults.

Type: string
Default: “”
Importance: low

Table mapping

mapping.map

JSON object mapping each <topic>.<keyspace>.<table> to its field-to-column mapping, e.g. {"orders.ecom.orders":"id=value.id, amount=value.amount"}. Use key.* to reference record-key fields (primary-key columns) and value.* for record-value fields. Each entry materializes to the engine key topic.<topic>.<keyspace>.<table>.mapping. A single topic may map to multiple tables (fan-out) by adding multiple entries.

Type: string
Default: “”
Importance: high

topic.override.map

Optional JSON object of per-table and per-topic overrides. Per-table keys are <topic>.<keyspace>.<table>.<setting> where <setting> is one of consistencyLevel, ttl, ttlTimeUnit, timestampTimeUnit, nullToUnset, deletesEnabled or query. Per-topic codec keys are <topic>.codec.<setting> where <setting> is one of locale, timeZone, timestamp, date, time or unit. Example: {"orders.ecom.orders.consistencyLevel":"LOCAL_QUORUM", "orders.ecom.orders.ttl":"3600", "orders.codec.timeZone":"UTC"}. Each entry materializes to the engine key topic.<entry-key>.

Type: string
Default: {}
Importance: medium

Connection tuning

maxConcurrentRequests

Maximum number of requests to send to the database at once.

Type: int
Default: 500
Valid Values: [1,…]
Importance: low

maxNumberOfRecordsInBatch

Maximum number of records sent in a single UNLOGGED batch request.

Type: int
Default: 32
Valid Values: [1,…]
Importance: low

queryExecutionTimeout

CQL statement execution timeout, in seconds.

Type: int
Default: 30
Valid Values: [1,…]
Importance: low

connectionPoolLocalSize

Number of connections the driver maintains to each node in the local datacenter.

Type: int
Default: 4
Valid Values: [1,…]
Importance: low

compression

Compression algorithm to use for requests to the database server.

Type: string
Default: None
Valid Values: LZ4, None, SNAPPY
Importance: low

Consumer configuration

max.poll.interval.ms

The maximum delay between subsequent consume requests to Kafka. This configuration property may be used to improve the performance of the connector, if the connector cannot send records to the sink system. Defaults to 300000 milliseconds (5 minutes).

Type: long
Default: 300000 (5 minutes)
Valid Values: [60000,…,1800000] for non-dedicated clusters and [60000,…] for dedicated clusters
Importance: low

max.poll.records

The maximum number of records to consume from Kafka in a single request. This configuration property may be used to improve the performance of the connector, if the connector cannot send records to the sink system. Defaults to 500 records.

Type: long
Default: 500
Valid Values: [1,…,500] for non-dedicated clusters and [1,…] for dedicated clusters
Importance: low

Number of tasks for this connector

tasks.max

Maximum number of tasks for the connector.

Type: int
Valid Values: [1,…]
Importance: high

Additional Configs

consumer.override.auto.offset.reset

Defines the behavior of the consumer when there is no committed position (which occurs when the group is first initialized) or when an offset is out of range. You can choose either to reset the position to the “earliest” offset (the default) or the “latest” offset. You can also select “none” if you would rather set the initial offset yourself and you are willing to handle out of range errors manually. More details: https://docs.confluent.io/platform/current/installation/configuration/consumer-configs.html#auto-offset-reset

Type: string
Importance: low

consumer.override.isolation.level

Controls how to read messages written transactionally. If set to read_committed, consumer.poll() will only return transactional messages which have been committed. If set to read_uncommitted (the default), consumer.poll() will return all messages, even transactional messages which have been aborted. Non-transactional messages will be returned unconditionally in either mode. More details: https://docs.confluent.io/platform/current/installation/configuration/consumer-configs.html#isolation-level

Type: string
Importance: low

header.converter

The converter class for the headers. This is used to serialize and deserialize the headers of the messages.

Type: string
Importance: low

key.converter.use.schema.guid

The schema GUID to use for deserialization when using ConfigSchemaIdDeserializer. This allows you to specify a fixed schema GUID to be used for deserializing message keys. Only applicable when key.converter.key.schema.id.deserializer is set to ConfigSchemaIdDeserializer.

Type: string
Importance: low

key.converter.use.schema.id

The schema ID to use for deserialization when using ConfigSchemaIdDeserializer. This allows you to specify a fixed schema ID to be used for deserializing message keys. Only applicable when key.converter.key.schema.id.deserializer is set to ConfigSchemaIdDeserializer.

Type: int
Importance: low

value.converter.allow.optional.map.keys

Allow optional string map key when converting from Connect Schema to Avro Schema. Applicable for Avro Converters.

Type: boolean
Importance: low

value.converter.auto.register.schemas

Specify if the Serializer should attempt to register the Schema.

Type: boolean
Importance: low

value.converter.connect.meta.data

Allow the Connect converter to add its metadata to the output schema. Applicable for Avro Converters.

Type: boolean
Importance: low

value.converter.enhanced.avro.schema.support

Enable enhanced schema support to preserve package information and Enums. Applicable for Avro Converters.

Type: boolean
Importance: low

value.converter.enhanced.protobuf.schema.support

Enable enhanced schema support to preserve package information. Applicable for Protobuf Converters.

Type: boolean
Importance: low

value.converter.flatten.unions

Whether to flatten unions (oneofs). Applicable for Protobuf Converters.

Type: boolean
Importance: low

value.converter.generate.index.for.unions

Whether to generate an index suffix for unions. Applicable for Protobuf Converters.

Type: boolean
Importance: low

value.converter.generate.struct.for.nulls

Whether to generate a struct variable for null values. Applicable for Protobuf Converters.

Type: boolean
Importance: low

value.converter.int.for.enums

Whether to represent enums as integers. Applicable for Protobuf Converters.

Type: boolean
Importance: low

value.converter.latest.compatibility.strict

Verify latest subject version is backward compatible when use.latest.version is true.

Type: boolean
Importance: low

value.converter.object.additional.properties

Whether to allow additional properties for object schemas. Applicable for JSON_SR Converters.

Type: boolean
Importance: low

value.converter.optional.for.nullables

Whether nullable fields should be specified with an optional label. Applicable for Protobuf Converters.

Type: boolean
Importance: low

value.converter.optional.for.proto2

Whether proto2 optionals are supported. Applicable for Protobuf Converters.

Type: boolean
Importance: low

value.converter.scrub.invalid.names

Whether to scrub invalid names by replacing invalid characters with valid characters. Applicable for Avro and Protobuf Converters.

Type: boolean
Importance: low

value.converter.use.latest.version

Use latest version of schema in subject for serialization when auto.register.schemas is false.

Type: boolean
Importance: low

value.converter.use.optional.for.nonrequired

Whether to set non-required properties to be optional. Applicable for JSON_SR Converters.

Type: boolean
Importance: low

value.converter.use.schema.guid

The schema GUID to use for deserialization when using ConfigSchemaIdDeserializer. This allows you to specify a fixed schema GUID to be used for deserializing message values. Only applicable when value.converter.value.schema.id.deserializer is set to ConfigSchemaIdDeserializer.

Type: string
Importance: low

value.converter.use.schema.id

The schema ID to use for deserialization when using ConfigSchemaIdDeserializer. This allows you to specify a fixed schema ID to be used for deserializing message values. Only applicable when value.converter.value.schema.id.deserializer is set to ConfigSchemaIdDeserializer.

Type: int
Importance: low

value.converter.wrapper.for.nullables

Whether nullable fields should use primitive wrapper messages. Applicable for Protobuf Converters.

Type: boolean
Importance: low

value.converter.wrapper.for.raw.primitives

Whether a wrapper message should be interpreted as a raw primitive at root level. Applicable for Protobuf Converters.

Type: boolean
Importance: low

errors.tolerance

Use this property if you would like to configure the connector’s error handling behavior. WARNING: This property should be used with CAUTION for SOURCE CONNECTORS as it may lead to dataloss. If you set this property to ‘all’, the connector will not fail on errant records, but will instead log them (and send to DLQ for Sink Connectors) and continue processing. If you set this property to ‘none’, the connector task will fail on errant records.

Type: string
Default: all
Importance: low

key.converter.key.schema.id.deserializer

The class name of the schema ID deserializer for keys. This is used to deserialize schema IDs from the message headers.

Type: string
Default: io.confluent.kafka.serializers.schema.id.DualSchemaIdDeserializer
Importance: low

key.converter.key.subject.name.strategy

How to construct the subject name for key schema registration.

Type: string
Default: TopicNameStrategy
Importance: low

key.converter.replace.null.with.default

Whether to replace fields that have a default value and that are null to the default value. When set to true, the default value is used, otherwise null is used. Applicable for JSON Key Converter.

Type: boolean
Default: true
Importance: low

key.converter.schemas.enable

Include schemas within each of the serialized keys. Input message keys must contain schema and payload fields and may not contain additional fields. For plain JSON data, set this to false. Applicable for JSON Key Converter.

Type: boolean
Default: false
Importance: low

value.converter.decimal.format

Specify the JSON/JSON_SR serialization format for Connect DECIMAL logical type values with two allowed literals:

BASE64 to serialize DECIMAL logical types as base64 encoded binary data and

NUMERIC to serialize Connect DECIMAL logical type values in JSON/JSON_SR as a number representing the decimal value.

Type: string
Default: BASE64
Importance: low

value.converter.flatten.singleton.unions

Whether to flatten singleton unions. Applicable for Avro and JSON_SR Converters.

Type: boolean
Default: false
Importance: low

value.converter.ignore.default.for.nullables

When set to true, this property ensures that the corresponding record in Kafka is NULL, instead of showing the default column value. Applicable for AVRO,PROTOBUF and JSON_SR Converters.

Type: boolean
Default: false
Importance: low

value.converter.reference.subject.name.strategy

Set the subject reference name strategy for value. Valid entries are DefaultReferenceSubjectNameStrategy or QualifiedReferenceSubjectNameStrategy. Note that the subject reference name strategy can be selected only for PROTOBUF format with the default strategy being DefaultReferenceSubjectNameStrategy.

Type: string
Default: DefaultReferenceSubjectNameStrategy
Importance: low

value.converter.replace.null.with.default

Whether to replace fields that have a default value and that are null to the default value. When set to true, the default value is used, otherwise null is used. Applicable for JSON Converter.

Type: boolean
Default: true
Importance: low

value.converter.schemas.enable

Include schemas within each of the serialized values. Input messages must contain schema and payload fields and may not contain additional fields. For plain JSON data, set this to false. Applicable for JSON Converter.

Type: boolean
Default: false
Importance: low

value.converter.value.schema.id.deserializer

The class name of the schema ID deserializer for values. This is used to deserialize schema IDs from the message headers.

Type: string
Default: io.confluent.kafka.serializers.schema.id.DualSchemaIdDeserializer
Importance: low

value.converter.value.subject.name.strategy

Determines how to construct the subject name under which the value schema is registered with Schema Registry.

Type: string
Default: TopicNameStrategy
Importance: low

Auto-restart policy

auto.restart.on.user.error

Enable connector to automatically restart on user-actionable errors.

Type: boolean
Default: true
Importance: medium

Frequently asked questions

Find answers to frequently asked questions about the DataStax Sink connector for Confluent Cloud.

When to choose Apache Cassandra or DSE versus DataStax Astra?

Set deployment.type to Apache Cassandra or DSE when you connect to a self-managed Apache Cassandra or DSE cluster using contact points, with optional SSL/TLS. Set it to DataStax Astra when you connect to an Astra DB database using an uploaded SCB. The two modes are mutually exclusive.

Why does the connector fail with a missing keyspace or table error?

The connector does not create keyspaces, tables, or UDTs. Create the target schema in your Cassandra, DSE, or Astra DB database before you start the connector, then confirm that each entry in mapping.map references an existing keyspace and table.

Can I use a custom Cassandra Query Language (CQL) query instead of the auto-generated INSERT?

Yes, using the query per-table override. Use this option only for idempotent statements. Because the connector provides at-least-once delivery, a conditional write such as IF NOT EXISTS or a counter update can apply more than once on retry.

Next Steps

For an example that shows fully managed Confluent Cloud connectors in action with Confluent Cloud for Apache Flink, see the Cloud ETL Demo. This example also shows how to use Confluent CLI to manage your resources in Confluent Cloud.