What are the new performance-related features introduced in Rails 7?

Rails 7 has brought a host of improvements, especially in the realm of performance. In this blog, we'll explore the new performance-related features in Rails 7 that can help you build faster and more efficient web applications.

Asynchronous Query Loading

One of the standout features of Rails 7 is its support for asynchronous query loading. Traditionally, database queries in Rails are executed synchronously, which can lead to slower response times, especially when dealing with complex queries or long-running database operations.

With Rails 7, you can take advantage of async query loading, allowing your application to perform other tasks while waiting for the query to complete. Here's a basic example of how it works:

1# Using async query loading in Rails 7
2posts = Post.where(published: true).load_async
3comments = Comment.where(approved: true).load_async
4
5# Continue performing other operations while queries are running
6do_some_processing
7
8# Wait for the queries to finish when you need the results
9published_posts = posts.to_a
10approved_comments = comments.to_a
11

This asynchronous approach can significantly improve the perceived performance of your application, making it much more responsive to users.

Improved Caching with Automatic Query Expiry

Rails 7 has enhanced caching mechanisms, notably through automatic query expiry. This feature ensures that cached query results are automatically invalidated when the underlying data changes. As a result, you can ensure your application always serves fresh data without manually managing cache expiration.

By using the cache_versioning option, Rails can associate cached data with a checksum of the query, automatically expiring cached results when the data changes:

1# Caching with automatic expiry in Rails 7
2Rails.cache.write('all_products', Product.all, cache_versioning: true)
3

This feature can help improve both the reliability and performance of your Rails applications by ensuring that cached data is current and accurate.

Turbo Streams for Real-time Updates

Turbo Streams, part of the Hotwire suite, is another exciting addition in Rails 7. Turbo Streams enable real-time updates by sending only the changes needed to update the web page, avoiding a full page reload. This is particularly beneficial for applications that require real-time data, such as chat apps or live dashboards.

For example, you can use Turbo Streams to update a list of comments dynamically as new comments are posted:

1<%= turbo_stream_from 'comments' %>
2
3<%= turbo_frame_tag 'comments' do %>
4  <%= render @comments %>
5<% end %>
6

In this setup, any changes to the comments will be pushed to the client, providing a seamless real-time update experience.

Parallel Testing for Faster Test Suites

Rails 7 has also introduced parallel testing, significantly speeding up test suite execution. By running tests in parallel, you can utilize multiple CPU cores, reducing the time it takes to run a complete test suite.

To enable parallel testing in a Rails 7 application, simply add the following to your test/test_helper.rb:

1# Enable parallel testing in Rails 7
2Parallelize(workers: :number_of_processors)
3

This approach can lead to substantial time savings, especially in larger applications with extensive test suites.

Conclusion

Rails 7 continues to build on the framework's long-standing strengths by introducing features that improve performance and efficiency. Asynchronous query loading, improved caching mechanisms, Turbo Streams, and parallel testing all contribute to a faster and more responsive application.

These enhancements not only improve developer productivity but also enhance the user experience, ensuring your applications remain competitive in a fast-paced digital landscape.

For further reading on Rails enhancements, check out Turbo Streams Guide and learn more about Parallel Testing in Rails.

Leverage these new tools in Rails 7 to build high-performance applications, and stay ahead in the world of web development.