Delivering data from an Apache Kafka® queue to YDB

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Updated at March 25, 2026

Required paid resources
Getting started
Prepare and activate the transfer
Test the transfer
Delete the resources you created

A Managed Service for YDB cluster can ingest data from Apache Kafka® topics in real time. This data is automatically added to YDB tables with topic names.

To start data delivery:

If you no longer need the resources you created, delete them.

Required paid resources

Managed Service for Apache Kafka® cluster: Computing resources allocated to hosts along with storage and backup capacity (see Managed Service for Apache Kafka® pricing).
Public IP addresses if public access is enabled for cluster hosts (see Virtual Private Cloud pricing).
Managed Service for YDB database (see Managed Service for YDB pricing). Its cost depends on the deployment mode:
- In serverless mode, you pay for data operations as well as the amount of stored data and backups.
- In dedicated instance mode, you pay for the use of computing resources allocated to the database, storage size, and backups.
Per transfer: Computing resources used and the number of data rows transferred (see Data Transfer pricing).

Getting started

Set up your data delivery infrastructure:
Manually

Terraform
1. Create a Managed Service for Apache Kafka® source cluster with any suitable configuration.
2. Create a Managed Service for YDB database with your preferred configuration.
3. In the source cluster, create a topic named sensors.
4. In the source cluster, create a user with the ACCESS_ROLE_PRODUCER and ACCESS_ROLE_CONSUMER permissions for the new topic.
1. If you do not have Terraform yet, install it.
2. Get the authentication credentials. You can add them to environment variables or specify them later in the provider configuration file.
3. Configure and initialize a provider. There is no need to create a provider configuration file manually, you can download it.
4. Place the configuration file in a separate working directory and specify the parameter values. If you did not add the authentication credentials to environment variables, specify them in the configuration file.
5. Download the data-transfer-mkf-ydb.tf configuration file to the same working directory.
  
  This file describes:
  - Network.
  - Subnet.
  - Security group and the rule required for connecting to the Managed Service for Apache Kafka® cluster.
  - Managed Service for Apache Kafka® source cluster.
  - Apache Kafka® topic.
  - Apache Kafka® user.
  - Managed Service for YDB database.
  - Transfer.
6. In the data-transfer-mkf-ydb.tf file, specify these variables:
  - source_kf_version: Apache Kafka® version in the source cluster.
  - source_user_name: Username for connection to the Apache Kafka® topic.
  - source_user_password: User password.
  - target_db_name: Managed Service for YDB database name.
  - transfer_enabled: 0 to ensure that no transfer is created before you manually create the target endpoint.
7. Validate your Terraform configuration files using this command:
  terraform validate
  Terraform will display any configuration errors detected in your files.
8. Create the required infrastructure:
  1. Run this command to view the planned changes:
    
    terraform plan
    
    If you described the configuration correctly, the terminal will display a list of the resources to update and their parameters. This is a verification step that does not apply changes to your resources.
  2. If everything looks correct, apply the changes:
    
    Run this command:
    
    terraform apply
    
    Confirm updating the resources.
    
    Wait for the operation to complete.
  All the required resources will be created in the specified folder. You can check resource availability and their settings in the management console.
The new source cluster Apache Kafka® topic named sensors will receive test data from car sensors in JSON format:
```
{
    "device_id":"iv9a94th6rzt********",
    "datetime":"2020-06-05 17:27:00",
    "latitude":"55.70329032",
    "longitude":"37.65472196",
    "altitude":"427.5",
    "speed":"0",
    "battery_voltage":"23.5",
    "cabin_temperature":"17",
    "fuel_level":null
}
```
Install these tools:
- kafkacat: For reading from and writing to Apache Kafka® topics.
```
sudo apt update && sudo apt install --yes kafkacat
```
  Check that you can use it to connect to the Managed Service for Apache Kafka® source cluster over SSL.
- jq: For stream processing of JSON files.
```
sudo apt update && sudo apt-get install --yes jq
```

Prepare and activate the transfer

Create a target endpoint:
- Database type: YDB.
- Endpoint parameters:
  - Connection settings:
    - Database: Select the Managed Service for YDB database from the list.
    - Service account ID: Select an existing service account or create a new one with the editor role.

Create a source endpoint:

Database type: Kafka.

Endpoint parameters:

Connection type: Managed Service for Apache Kafka cluster.

Select your source cluster from the list and specify its connection settings.

Advanced settings → Conversion rules.

Data format: JSON.

Data scheme: You can specify a schema using one of these two methods:

Field list.

Set a list of topic fields manually:

Name	Type	Key
`device_id`	`STRING`	Yes
`datetime`	`STRING`
`latitude`	`DOUBLE`
`longitude`	`DOUBLE`
`altitude`	`DOUBLE`
`speed`	`DOUBLE`
`battery_voltage`	`DOUBLE`
`cabin_temperature`	`UINT16`
`fuel_level`	`UINT16`

JSON specification.

Create and upload a data schema file in JSON format, json_schema.json:

json_schema.json

[
    {
        "name": "device_id",
        "type": "string",
        "key": true
    },
    {
        "name": "datetime",
        "type": "string"
    },
    {
        "name": "latitude",
        "type": "double"
    },
    {
        "name": "longitude",
        "type": "double"
    },
    {
        "name": "altitude",
        "type": "double"
    },
    {
        "name": "speed",
        "type": "double"
    },
    {
        "name": "battery_voltage",
        "type": "double"
    },
    {
        "name": "cabin_temperature",
        "type": "uint16"
    },
    {
        "name": "fuel_level",
        "type": "uint16"
    }
]

Create a transfer:
Manually

Terraform
1. Create a transfer of the Replication-type that will use the endpoints you created.
2. Activate the transfer.
1. In the data-transfer-mkf-ydb.tf file, specify the following variables:
  - source_endpoint_id: Source endpoint ID.
  - target_endpoint_id: Target endpoint ID.
  - transfer_enabled: Set to 1 to create the transfer.
2. Validate your Terraform configuration files using this command:
  terraform validate
  Terraform will display any configuration errors detected in your files.
3. Create the required infrastructure:
  1. Run this command to view the planned changes:
    
    terraform plan
    
    If you described the configuration correctly, the terminal will display a list of the resources to update and their parameters. This is a verification step that does not apply changes to your resources.
  2. If everything looks correct, apply the changes:
    
    Run this command:
    
    terraform apply
    
    Confirm updating the resources.
    
    Wait for the operation to complete.
  The transfer will be activated automatically upon creation.

Test the transfer

Wait for the transfer status to change to Replicating.

Make sure that the data from the topic in the source Managed Service for Apache Kafka® cluster is being transferred to the Managed Service for YDB database:

Create a file named sample.json with test data:

{
    "device_id": "iv9a94th6rzt********",
    "datetime": "2020-06-05 17:27:00",
    "latitude": 55.70329032,
    "longitude": 37.65472196,
    "altitude": 427.5,
    "speed": 0,
    "battery_voltage": 23.5,
    "cabin_temperature": 17,
    "fuel_level": null
}

{
    "device_id": "rhibbh3y08qm********",
    "datetime": "2020-06-06 09:49:54",
    "latitude": 55.71294467,
    "longitude": 37.66542005,
    "altitude": 429.13,
    "speed": 55.5,
    "battery_voltage": null,
    "cabin_temperature": 18,
    "fuel_level": 32
}

{
    "device_id": "iv9a94th6rzt********",
    "datetime": "2020-06-07 15:00:10",
    "latitude": 55.70985913,
    "longitude": 37.62141918,
    "altitude": 417.0,
    "speed": 15.7,
    "battery_voltage": 10.3,
    "cabin_temperature": 17,
    "fuel_level": null
}

Send data from sample.json to the Managed Service for Apache Kafka® sensors topic using jq and kafkacat:

jq -rc . sample.json | kafkacat -P \
   -b <broker_host_FQDN>:9091 \
   -t sensors \
   -k key \
   -X security.protocol=SASL_SSL \
   -X sasl.mechanisms=SCRAM-SHA-512 \
   -X sasl.username="<username_in_source_cluster>" \
   -X sasl.password="<user_password_in_source_cluster>" \
   -X ssl.ca.location=/usr/local/share/ca-certificates/Yandex/YandexInternalRootCA.crt -Z

The data is sent on behalf of the created user. To learn more about setting up an SSL certificate and using kafkacat, see Connecting to an Apache Kafka® cluster from applications.

Make sure the data from the Managed Service for Apache Kafka® source cluster has been transferred to the Managed Service for YDB database:
Management console

YDB CLI
1. In the management console, select the folder containing your database.
2. Navigate to the Managed Service for YDB service.
3. Select your database from the list.
4. Navigate to the Navigation tab.
5. Check that the Managed Service for YDB database contains a table named sensors with the test data from the topic.
1. Connect to the Managed Service for YDB database.
2. Check that the database contains a table named sensors with the test data from the topic:
  ydb table query execute \ --query "SELECT * \ FROM sensors"

Delete the resources you created

Note

Before deleting any resources, deactivate the transfer.

To minimize resource consumption, delete the resources you no longer need:

Delete the transfer.
Delete the source and target endpoints.
If you created a service account when creating the target endpoint, delete it.
Delete the rest of the resources depending on how you created them:
Manually

Terraform
1. Delete the Managed Service for Apache Kafka® cluster.
2. Delete the Managed Service for YDB database.
1. In the terminal window, go to the directory containing the infrastructure plan.
  
  Warning
  
  Make sure the directory has no Terraform manifests with the resources you want to keep. Terraform deletes all resources that were created using the manifests in the current directory.
2. Delete resources:
  1. Run this command:
    
    terraform destroy
  2. Confirm deleting the resources and wait for the operation to complete.
  All the resources described in the Terraform manifests will be deleted.

Delivering data from an Apache Kafka® queue to YDB

Required paid resourcesRequired paid resources

Getting startedGetting started

Prepare and activate the transferPrepare and activate the transfer

Test the transferTest the transfer

Delete the resources you createdDelete the resources you created

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Required paid resources

Getting started

Prepare and activate the transfer

Test the transfer

Delete the resources you created