how to run superset in async query

Lussy04

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25-01-2025

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Superset, a popular data exploration and visualization platform, excels at interactive data analysis. However, complex queries can sometimes lead to performance bottlenecks. Running Superset in asynchronous query mode can significantly improve responsiveness and user experience, allowing users to continue interacting with the interface while long-running queries execute in the background. This article will guide you through the process of configuring and utilizing asynchronous queries in Superset.

Understanding Asynchronous Queries in Superset

In a synchronous query, Superset waits for the database query to complete before returning a response to the user. This means the user interface becomes unresponsive until the query finishes. This is problematic for lengthy queries. Asynchronous queries, conversely, send the query to the database and immediately return control to the user. The results are then fetched and displayed once the query completes. This maintains a responsive interface, even during prolonged data processing.

Prerequisites: Setting the Stage for Async Queries

Before diving into the configuration, ensure you have the following:

• A properly installed and configured Superset instance: Follow the official Superset documentation for installation and setup instructions tailored to your operating system and preferred method. Link to Superset Documentation
• A compatible database connection: Superset supports various databases (PostgreSQL, MySQL, etc.). Ensure your database connection is properly configured within Superset.
• Understanding of your database's capabilities: Asynchronous query handling relies on the database's ability to handle concurrent operations efficiently. Some databases may require specific settings or configurations to optimize asynchronous processing.

Configuring Superset for Asynchronous Queries

Superset's configuration for asynchronous queries primarily involves adjusting the celery settings. Celery is a distributed task queue that Superset uses to handle background tasks, including asynchronous queries. Here's how to configure it:

1. Celery Installation and Configuration

• Install Celery: If Celery isn't already installed, use pip: pip install celery
• Configure Celery: You'll need to configure your Celery broker. RabbitMQ or Redis are commonly used. The specifics of configuring the broker are outside the scope of this document; refer to the Celery documentation for detailed instructions. Link to Celery Documentation
• Superset Configuration: Adjust Superset's configuration file (superset_config.py) to include Celery settings. The key settings are CELERY_BROKER_URL (pointing to your Celery broker) and CELERY_RESULT_BACKEND (specifying where Celery stores task results).

2. Superset's superset_config.py Modifications

You'll need to add or modify entries in your superset_config.py file. This will likely involve setting:

• CELERY_BROKER_URL: The URL of your message broker (e.g., redis://localhost:6379/0 for Redis).
• CELERY_RESULT_BACKEND: Where Celery stores results (e.g., redis://localhost:6379/0 for Redis).
• SQLALCHEMY_DATABASE_URI: The database connection string for your Superset metadata database.

A sample snippet (replace with your actual settings):

CELERY_BROKER_URL = 'redis://localhost:6379/0'
CELERY_RESULT_BACKEND = 'redis://localhost:6379/0'
SQLALCHEMY_DATABASE_URI = 'postgresql://user:password@host:port/database'

3. Restarting Superset

After modifying the configuration file, restart your Superset instance to apply the changes.

Verifying Asynchronous Query Execution

After configuration, you can verify if Superset is indeed using asynchronous queries. Observe the behavior of your queries. If the interface remains responsive while long-running queries execute, it's likely working as expected. You may also check the Celery monitoring tools (if you've configured them) to monitor the progress of your background tasks.

Troubleshooting Asynchronous Queries

If you encounter issues, here are some common troubleshooting steps:

• Check Celery Logs: Examine Celery's logs for any errors or warnings.
• Verify Broker Connection: Ensure your Celery broker is running and accessible.
• Review Superset Logs: Look for Superset logs for any relevant error messages.
• Database Connection: Ensure your database connection is stable and correctly configured.

Conclusion

Implementing asynchronous queries in Superset significantly enhances the user experience by preventing interface freezes during lengthy data processing. By configuring Celery correctly and following the steps outlined above, you can unlock a more responsive and efficient Superset environment for all your data exploration needs. Remember to consult the official Superset and Celery documentation for the most up-to-date information and detailed instructions.