Redis Sink Connector for Confluent Cloud

The fully-managed Redis Sink connector for Confluent Cloud is used to export data from Apache Kafka® topics to Redis. The connector works with Redis Enterprise Cloud, Azure Cache for Redis, and Amazon ElastiCache for Redis

Note

Features

  • At least once delivery: The connector guarantees that records are delivered at least once.
  • Supports multiple tasks: The connector supports running one or more tasks.
  • SSL support: Supports one-way SSL.
  • Deletions: The connector supports deletions. If the record stored in Kafka has a null value, the connector sends a delete message with the corresponding key to Redis. Note that the connector always expects non-null keys.
  • Supported input data formats: This connector supports storing raw bytes or strings (as inserts) in Redis.

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

Be sure to review the following information.

Quick Start

Use this quick start to get up and running with the Confluent Cloud Redis Sink connector. The quick start provides the basics of selecting the connector and configuring it to stream events to Redis.

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. See Install the Confluent CLI.
  • Schema Registry must be enabled to use a Schema Registry-based format (for example, Avro, JSON_SR (JSON Schema), or Protobuf). See Schema Registry Enabled Environments for additional information.
  • Access to one of the following fully-managed Redis services:
    • Redis Enterprise Cloud
    • Azure Cache for Redis
    • Amazon ElastiCache for Redis. Note that to use this service, your Kafka cluster must be VPC peered.
  • Redis credentials, hostname, and database index name.
  • The Redis instance must be in the same region as your Confluent Cloud cluster.
  • 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

See the Quick Start for Confluent Cloud for installation instructions.

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 Redis Sink connector card.

Redis Sink Connector Card

Step 4: Enter the connector details

Note

  • Ensure you have all your prerequisites completed.
  • An asterisk ( * ) designates a required entry.

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

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.

Step 5: Check the results in Redis.

Verify that data is populating the Redis instance.

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. See View Connector Dead Letter Queue Errors in Confluent Cloud for details.

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 required and optional connector properties.

{
  "name": "RedisSinkConnector_0",
  "config": {
    "topics": "pageviews",
    "connector.class": "RedisSink",
    "name": "RedisSinkConnector_0",
    "input.data.format": "BYTES",
    "kafka.auth.mode": "KAFKA_API_KEY",
    "kafka.api.key": "<my-kafka-api-key>",
    "kafka.api.secret": "<my-kafka-api-secret>",
    "redis.hostname": "test.redis.cache.windows.net",
    "redis.portnumber": "6380",
    "redis.database": "1",
    "redis.password": "********************************************",
    "redis.ssl.mode": "enabled",
    "tasks.max": "1"
  }
}

Note the following property definitions:

  • "name": Sets a name for your new connector.
  • "connector.class": Identifies the connector plugin name.
  • "topics": Identifies the topic name or a comma-separated list of topic names.
  • "input.data.format": Sets the input Kafka record value format (data coming from the Kafka topic). Valid entries are BYTES or STRING. If the Kafka topic is using JSON or a schema-based format, like Avro, you should select BYTES.

  • "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

  • "redis.ssl.mode": Sets the SSL mode for the connection. Options are enabled, disabled, server, and server+client. The default is disabled. If set the property to enabled, the connector uses SSL to make the connection. If you select server, the connector uses a truststore. If you select server+client, the connector uses both the truststore and a keystore with a valid key pair and the associated certificate.

    • "redis.ssl.mode": "server": If you use SSL mode server, the connector uses a truststore CA certificate to secure the connection. You add two additional properties: redis.ssl.truststore.file and redis.ssl.truststore.password. A truststore file is a binary file. For the redis.ssl.truststore.file property, you encode the binary truststore file in base64, take the encoded string, add the data:text/plain;base64 prefix, and then specify the entire string as the property entry. For example: "redis.ssl.truststore.file" : "data:text/plain;base64,/u3+7QAAAAIAAAACAAAAAQAGY2xpZ...==".
    • "redis.ssl.mode": "server+client": If you use SSL mode server+client, the connector uses a truststore CA certificate and an additional keystore to secure the connection. You add four additional properties: redis.ssl.truststore.file, redis.ssl.truststore.password, redis.ssl.keystore.file, and redis.ssl.keystore.password. The truststore and keystore files are binary files. For the redis.ssl.truststore.file and redis.ssl.keystore.file properties, you encode the binary truststore and keystore files in base64, take the encoded string, add the data:text/plain;base64 prefix, and then specify the entire string as the property entry. For example: "redis.ssl.keystore.file" : "data:text/plain;base64,/u3+7QAAAAIAAAACAAAAAQAGY2xpZ...==".

  • "tasks.max": Maximum tasks for the connector to use. More tasks may improve performance.

See Configuration Properties for all property values and descriptions.

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 redis-sink-config.json

Example output:

Created connector RedisSinkConnector_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   | RedisSinkConnector_0  | RUNNING | sink

Step 6: Check the results in Redis.

Verify that data is populating the Redis instance.

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. See View Connector Dead Letter Queue Errors in Confluent Cloud for details.

Configuration Properties

Use the following configuration properties with the fully-managed connector. For self-managed connector property definitions and other details, see the connector docs in Self-managed connectors for Confluent Platform.

Which topics do you want to get data from?

topics

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

  • Type: list
  • 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

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

Input messages

input.data.format

Sets the input Kafka record value format. BYTES will pass keys as they are serialized in Kafka, while STRING will enforce a UTF-8 encoding on record values

  • Type: string
  • Importance: high
input.key.format

Sets the input Kafka record key format. BYTES will pass keys as they are serialized in Kafka, while STRING will enforce a UTF-8 encoding on keys.

  • Type: 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.

  • Type: string
  • Default: KAFKA_API_KEY
  • Valid Values: KAFKA_API_KEY, SERVICE_ACCOUNT
  • 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

How should we connect to your Redis server?

redis.hostname

Hostname of Redis server.

  • Type: string
  • Importance: high
redis.portnumber

Port number of Redis server.

  • Type: int
  • Importance: high
redis.client.mode

Whether Redis server is running on one or multiple nodes.

  • Type: string
  • Default: Standalone
  • Importance: high
redis.database

DB index that you want to write to.

  • Type: int
  • Default: 0
  • Importance: high
redis.password

Password for Redis server.

  • Type: password
  • Importance: medium

SSL configuration

redis.ssl.mode

How the Redis server is secured. ‘server’ requires a truststore with CA certificate. ‘server+client’ additionally requires a keystore with a valid certificate/key pair.

  • Type: string
  • Default: disabled
  • Importance: medium
redis.ssl.keystore.file

The key store containing server certificate.

  • Type: password
  • Importance: low
redis.ssl.keystore.password

The store password for the key store file.

  • Type: password
  • Importance: low
redis.ssl.truststore.file

The trust store containing server CA certificate.

  • Type: password
  • Importance: low
redis.ssl.truststore.password

The trust store password containing server CA certificate.

  • Type: password
  • 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

Next Steps

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

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