Use Your Own Data to Train a Machine Learning Model and Get Recommendations Based on Users' Browsing History

You will use Swagger UI, via any web browser, to call the Personalized Recommendation service APIs. Swagger UI allows developers to effortlessly interact and try out every single operation an API exposes for easy consumption. For more information, see Swagger UI.

In the service key you created for Personalized Recommendation in the previous tutorial: Use the Free Tier Service Plan to Set Up Account for Personalized Recommendation and Get Service Key, you should find (outside the uaa section of the service key) an entry called url (as highlighted in the image below).

1. To access the Personalized Recommendation Swagger UI, add /doc to the url value, paste it into any web browser and press Enter.

   

2. To be able to use the Swagger UI endpoints, you need to authorize yourself. In the top right corner, click Authorize.

   

3. Get the access_token value created in the previous tutorial: Get OAuth Access Token for Personalized Recommendation via Web Browser, then add Bearer in front of it, and enter in the Value field.

   bearer <access_token>
   

   

4. Click Authorize and then click Close.

   

The training endpoint can only receive an input in the form of a ZIP file. The ZIP file should contain two files: the Clickstream file and the Item Catalogue file. Here’s an overview of these files:

Clickstream file

Overview

Clickstream data is essential in understanding customer behavior based on the sequences of historical item interactions for each user. This data enables the model to do the following:

• Learn relations between items that appear in the same context, for example, user session item.

• Identify browsing patterns for each user, providing the basis for personalized recommendations, for example, for users with different histories interacting with the same item.

• (If item catalogue is provided) learn relations between items and their attributes, for example, from consecutive items in the same session belonging to the same category or having a similar name.

• (If user metadata is provided) learn relations between user’s attributes and item interaction sequences, for example, users with the same attribute values have different histories of item interactions.

To cover a wide range of recommendation domains or business scenarios, the clickstream schema detailed below is domain agnostic. Data size limits and content recommendations are provided in the subsequent sections.

Data schema

The clickstream is a CSV file with the following columns:

• userId: raw user ID (string)

• itemId: raw item ID (string).

• timestamp: timestamp (float).

Each row represents an event defined by the tuple (user, item, time). Note the agnostic nature of the event definition: it may refer to any type of user-item interaction, for example, view, add to cart, subscribe, rate, and so on. When preparing the clickstream data to fit this format, it’s up to you to determine which type of events to export. All events are treated as one type by the model.

Click on data to download a sample clickstream file for your reference.

Item catalogue file

Overview

The item catalogue provides additional information on the items in the form of categorical and text features. This information can be used by the model in the following ways:

• To improve the quality of the predictions: more item information results in more patterns in the clickstream data being identified and forecast.

• To support item cold start: approximate item representations (for example, embeddings) based on attribute representations.

• To give flexibility during inference: item attributes may be customized (modified attribute values and/or weights), influencing the recommendations.

• To enable smart search: as the model learns to represent words and item attributes, it can take them as inputs to recommend relevant items.

To avoid ambiguity in interpreting the attributes and standardize the catalogue format, the data schema has been fixed, as described in the next section. Additional information on size limits and recommended content of the catalogue is provided in the subsequent sections.

Therefore, while not mandatory, it’s highly recommended to have the item catalogue together with the clickstream data and unlock the full potential of the recommendation engine.

Data Schema

The item catalogue is a JSON file with the following structure:

```
{
    raw item ID (string): {
        'categoricalFeatures': {
            categorical attribute (string): {
                'values': attribute values (list of strings),
                'weights' (optional): attribute weights (list of float)
            },
            ...
        },
        'textFeatures': {
            text attribute (string): attribute value (string),
            ...
        },
        'numericalFeatures': {
            numerical attribute (string): attribute value (float),
            ...
        },
        'unavailable' (optional): availability flag (boolean)
    }
}
```

Click on data to download a sample item catalogue file for your reference.

Use the POST /standard/rs/v1/tenants/{tenant}/jobs/file-upload endpoint to upload data and trigger the machine learning model training job.

1. Click the endpoint name to expand it.

2. Click Try it out.

   

3. Enter tenant name. You must enter a name for the tenants, so please input a name of your choice.

4. Upload Data. Choose the ZIP file that contains the newly created training data.

5. Enter site name. A site name is also required, but if you leave this field blank, it is automatically filled with “default”.

   

6. Set serve_model to true. Make this setting to automatically deploy the real-time model serving instance.

   

7. Click the Execute button. Bear in mind that users with the free tier model for SAP BTP are limited to a total number of 2 trainings per month. When you call the third training API, you get a 403 response stating that you have exceeded your quota for the month.

After you trigger the training, there are two possible outcomes:

• Still ongoing, where the status is “PENDING”, and code 200.

  

• Conflict, where the trigger clashed with the ongoing training from the previous trigger. The status is “Previously submitted job still in progress”, and the code is 409.

  

Use the GET /standard/rs/v1/tenants/{tenant}/jobs/latest endpoint to check the status of the ongoing training job.

1. Click the endpoint name to expand it.

2. Click Try it out.

3. Enter tenant name and site name (must be exactly the same as in the previous step). Click Execute.

There are three possible outcomes:

• Job is still ongoing, with the status “SUBMITTED” and code 200. Please wait for around 5–10 minutes before rechecking the progress.

  

• The job is completed, with the status “SUCCEEDED” and code 200. You can now proceed to the next step.

  

• The job fails, with status “FAILED” and code 200. Please retrigger the training and make sure that you have entered all information correctly.

  

There are four different choices of inference calls as you can see in Inference Options. For this tutorial, we will use next-item recommendations.

Use the POST /standard/rs/v1/tenants/{tenant}/recommendations/next-items endpoint to get next-item recommendations.

1. Click the endpoint name to expand it.

   

2. Click Try it out.

3. Insert payload.

   Here, you provide all the relevant inference input data in the payload. Each of the different inference endpoints has different requirements: For next_items, the items_ls parameter is required while the other parameters are not required (but imputable). The items_ls parameter is a list of items_id representing the past item interactions (clickstream) of the user to generate the recommendations.

   For this parameter to be valid, the input must meet the following requirements:

   • Correspond to an object entry in the item_Catalogue training data used to train the model, or

   • Be provided as an entry in the metadata parameter as a cold start item, or

   • Be provided as a cold start item via the ‘metadata update’ feature

   Taking an example from our sample dataset, insert a payload with the following content:

   JSON

   Copy

   {
      "items_ls":[
         "2858"
      ]
   }
   

   For more details regarding the payload input, please refer to Next-Item Recommendations.

4. Enter tenant name and site name (must be exactly the same as in the previous steps). Click Execute.

You can expect the following responses:

• The model is able to understand the request and successfully return a set of recommendations. This returns a 200 code, stating the recommended items with their respective confidence scores.

  

• The user entered an incorrect payload. This returns a 400 code, stating that the model doesn’t understand the payload request.

  

• Forbidden. The user has exceeded their inference quota for the month. A short message is displayed with code 403. Bear in mind that users with the free tier model for SAP BTP are limited to a total number of 1000 inference requests per month.

  

• The training process has not finished yet. This returns a 404 code, stating that no model instances were found.

  

You have now successfully used the Personalized Recommendation service and your own dataset to train a machine learning model and get recommendations based on users’ browsing history and/or item description.