Yandex Data Streams streaming data processing

In this example, you will run streaming data processing on New York City taxi ride data. Data for the example will be written to a dedicated Yandex Data Streams stream by a generator.

The result will be the total fare of the first ten rides written to the stream after processing started.

To run this example:

1. Get ready to work.
2. Create a data stream.
3. Set up data generation.
4. Run the query.
5. Check the result.

Get ready to workGet ready to work

1. Log in to the management console or sign up if you have not already. If you have not signed up yet, navigate to the management console and follow the instructions.
2. On the Yandex Cloud Billing page, make sure you have an ACTIVE or TRIAL_ACTIVE billing account. If you do not have a billing account yet, create one.
3. If you do not have a folder yet, create one.
4. We will connect to the data stream using a service account. Create a service account named datastream-connection-account and assign it the ydb.editor role.
5. Data streams use Yandex Managed Service for YDB. You will need to create a serverless database.

Create a data streamCreate a data stream

1. In the management console, select the folder where you need to create a data stream.
2. Navigate to Data Streams.
3. Click Create stream.
4. Specify the Yandex Managed Service for YDB database created earlier.
5. Name the data stream: yellow-taxi.
6. Click Create.

Set up data generationSet up data generation

1. Create a connection:

   1. In the management console, select the folder where you want to create a connection.
   2. Navigate to Yandex Query.
   3. In the left-hand panel, select Tutorial.
   4. Navigate to Streaming.
   5. Under Create infrastructure for tutorial, click Create connection.
   6. In the window that opens, under Connection type parameters, select the database and service account you created earlier.
   7. Click Create.

2. Create a data binding:

   1. This will open the create data binding page.
   2. Under Binding parameters, select the yellow-taxi stream you created earlier.
   3. Click Create.

The generator will start writing data to the yellow-taxi stream. You can control the generator using the Stop and Start buttons.

Run the queryRun the query

1. In the query editor within the Query interface, click New streaming query.

2. Enter the query text in the text field:

   $data = 
   SELECT 
       *
   FROM
       bindings.`tutorial-streaming` LIMIT 10;
   
   SELECT
       HOP_END() AS time,
       COUNT(*) AS ride_count,
       SUM(total_amount) AS total_amount
   FROM 
       $data
   GROUP BY 
       HOP(CAST(tpep_pickup_datetime AS Timestamp), "PT1M", "PT1M", "PT1M");
   

3. Click Run.

Check the resultCheck the result

Once completed, the query returns the total fare (total_amount) of the first 10 rides written to the stream after processing started.

Useful linksUseful links

• HOP operator and window parameters in streaming data processing
• Aggregate functions in YQL
• SQL syntax
• Streaming data analysis