Delivering data from Yandex Managed Service for Apache Kafka® to Yandex Managed Service for YDB

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Before you begin
Prepare and activate the transfer
Test the 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 these resources, delete them.

Before you begin

Prepare the data delivery infrastructure:
Manually

Using Terraform
1. Create a Managed Service for Apache Kafka® source cluster with 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 to the created topic.
1. If you don't have Terraform, install and configure it.
2. Download the file with provider settings. Place it in a separate working directory and specify the parameter values.
3. Download the configuration file data-transfer-mkf-ydb.tf to the same working directory.
  
  This file describes:
  - Network.
  - Subnet.
  - Security groups and the rule required to connect to a Managed Service for Apache Kafka® cluster.
  - Managed Service for Apache Kafka® source cluster.
  - Apache Kafka® topic.
  - Managed Service for YDB database.
  - Transfer.
4. In the data-transfer-mkf-ydb.tf file, specify the variables:
  - source_kf_version: Apache Kafka® version in the source cluster.
  - source_user_name: Username for establishing a connection to the Apache Kafka® topic.
  - source_user_password: User password.
  - target_db_name: Managed Service for YDB database name.
  - transfer_enabled: Set 0 to ensure that no transfer is created before creating a target endpoint manually.
5. Run the command terraform init in the directory with the configuration file. This command initializes the provider specified in the configuration files and enables you to use the provider resources and data sources.
6. Make sure the Terraform configuration files are correct using the command:
  terraform validate
  If there are errors in the configuration files, Terraform will point to them.
7. Create the required infrastructure:
  1. Run the command to view planned changes:
    
    terraform plan
    
    If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.
  2. If you are happy with the planned changes, apply them:
    
    Run the command:
    
    terraform apply
    
    Confirm the update of 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 created Apache Kafka® sensors topic in the source cluster will receive test data from car sensors in JSON format:
```
{
    "device_id":"iv9a94th6rztooxh5ur2",
    "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
```

Prepare and activate the transfer

Create a target endpoint:
- Database type: YDB.
- Endpoint parameters:
  - Connection settings:
    - Database: Select a 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: Apache Kafka®.

Endpoint parameters:

Connection settings: Managed Service for Apache Kafka® cluster.

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

Advanced settings → Conversion rules.

Data format: JSON.

Data schema: 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 the json_schema.json file in JSON format:

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

Using Terraform
1. Create a transfer of the Increment type that will use the created endpoints.
2. Activate it.
1. In the data-transfer-mkf-ydb.tf file, specify the variables:
  - source_endpoint_id: ID of the source endpoint.
  - target_endpoint_id: ID of the target endpoint.
  - transfer_enabled: Set 1 to enable transfer creation.
2. Make sure the Terraform configuration files are correct using the command:
  terraform validate
  If there are errors in the configuration files, Terraform will point to them.
3. Create the required infrastructure:
  1. Run the command to view planned changes:
    
    terraform plan
    
    If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.
  2. If you are happy with the planned changes, apply them:
    
    Run the command:
    
    terraform apply
    
    Confirm the update of resources.
    
    Wait for the operation to complete.
  Once created, a transfer is activated automatically.

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 YDB cluster is being moved to the Managed Service for Apache Kafka® database:

Create a sample.json file with the following test data:

{
    "device_id": "iv9a94th6rztooxh5ur2",
    "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": "rhibbh3y08qmz3sdbrbu",
    "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": "iv9a94th6rztooxh5ur2",
    "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 the source cluster>" \
   -X sasl.password="<user password in the source cluster>" \
   -X ssl.ca.location=/usr/local/share/ca-certificates/Yandex/YandexCA.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 topics in an Apache Kafka® cluster.

Make sure that 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 desired DB.
2. In the list of services, select Managed Service for YDB.
3. Select the database from the list.
4. Go to the Navigation tab.
5. Check that the Managed Service for YDB database contains the sensors table with the test data from the topic.
1. Connect to the Managed Service for YDB database.
2. Check that the database contains the sensors table with the test data from the topic:
  ydb table query execute \ --query "SELECT * \ FROM sensors"

Delete the resources you created

Note

Before deleting the created resources, disable the transfer.

If you no longer need these resources, delete them:

Delete the transfer.
Delete endpoints for the source and target.
If you created the service account along with the target endpoint, delete it.

Delete the other resources, depending on the method used to create them:

Manually

Using Terraform

In the terminal window, change to the directory containing the infrastructure plan.
Delete the configuration file data-transfer-mkf-ydb.tf.
Make sure the Terraform configuration files are correct using the command:
```
terraform validate
```
If there are errors in the configuration files, Terraform will point to them.
Confirm the update of resources.
1. Run the command to view planned changes:
```
terraform plan
```
  If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.
2. If you are happy with the planned changes, apply them:
  1. Run the command:
```
terraform apply
```
  2. Confirm the update of resources.
  3. Wait for the operation to complete.
All the resources described in the configuration file data-transfer-mkf-ydb.tf will be deleted.

Delivering data from Yandex Managed Service for Apache Kafka® to Yandex Managed Service for YDB

Before you begin

Prepare and activate the transfer

Test the transfer

Delete the resources you created

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