Delivering data from an Apache Kafka® queue to YDB

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Updated at May 5, 2025

Required paid resources
Getting started
Set up and activate the transfer
Test your transfer
Delete the resources you created

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

To run data delivery:

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

Required paid resources

The support cost includes:

Managed Service for Apache Kafka® cluster fee: Using computing resources allocated to hosts (including ZooKeeper hosts) and disk space (see Apache Kafka® pricing).
Fee for using public IP addresses if public access is enabled for cluster hosts (see Virtual Private Cloud pricing).
Fee for the Managed Service for YDB database. The charge depends on the usage mode:
- For the serverless mode, you pay for data operations and the amount of stored data.
- For the dedicated instance mode, you pay for the use of computing resources, dedicated DBs, and disk space.
Learn more about the Managed Service for YDB pricing plans.
Transfer fee: Use of computing resources and the number of transferred data rows (see Data Transfer pricing).

Getting started

Prepare the data transfer infrastructure:
Manually

Terraform
1. Create a Managed Service for Apache Kafka® source cluster in any suitable configuration.
2. Create a Managed Service for YDB database in any suitable 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 to connect to a Managed Service for Apache Kafka® cluster.
  - Managed Service for Apache Kafka® source cluster.
  - Apache Kafka® topic.
  - Apache Kafka® user.
  - Database: Managed Service for YDB.
  - 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. Make sure the Terraform configuration files are correct using this command:
  terraform validate
  If there are any errors in the configuration files, Terraform will point them out.
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 source cluster's new Apache Kafka® topic, 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 the utilities:
- kafkacat to read and write data 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 JSON file stream processing.
```
sudo apt update && sudo apt-get install --yes jq
```

Set up 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 or create a service account with the editor role.

Create a source endpoint:

Database type: Kafka.

Endpoint parameters:

Connection type: Managed Service for Apache Kafka cluster.

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

Advanced settings → Conversion rules.

Data format: JSON.

Data scheme: You can specify a schema in two ways:

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 json_schema.json data schema file:

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 your transfer.
1. In the data-transfer-mkf-ydb.tf file, specify these variables:
  - source_endpoint_id: ID of the source endpoint.
  - target_endpoint_id: Target endpoint ID.
  - transfer_enabled: 1 to create a transfer.
2. Make sure the Terraform configuration files are correct using this command:
  terraform validate
  If there are any errors in the configuration files, Terraform will point them out.
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.
  Once created, your transfer will be activated automatically.

Test your transfer

Wait until the transfer status switches to Replicating.

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

Create a sample.json file 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 the sample.json file 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 working with kafkacat, see Connecting to a Apache Kafka® cluster from applications.

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

YDB CLI
1. In the management console, select the folder with the DB you need.
2. From the list of services, select Managed Service for YDB.
3. Select the 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 the resources you created, deactivate the transfer.

Some resources are not free of charge. To avoid paying for them, delete the resources you no longer need:

Delete the transfer.
Delete the endpoints for both the source and target.
If you had created a service account when creating the target endpoint, delete it.

Delete the other resources depending on how they were created:

Manually

Terraform

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.
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

Set up and activate the transferSet up and activate the transfer

Test your transferTest your transfer

Delete the resources you createdDelete the resources you created

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Required paid resources

Getting started

Set up and activate the transfer

Test your transfer

Delete the resources you created