Introduction to FusionCache

Summary

In this episode of Open at Microsoft, JY introduces Fusion Cache, an open-source caching library designed to simplify data access and caching. The library supports both in-memory and distributed caching, offering a hybrid solution that scales easily without changing the existing code. Key features include cache stampede protection, auto-recovery, and ease of use, making it ideal for developers working with scalable systems. With a simple API and the ability to protect against common caching issues, Fusion Cache enhances developer experience while providing a robust solution for performance optimization.

Takeaways

• 😀 Fusion Cache is an open-source caching library that simplifies data access and caching for developers.
• 😀 It combines in-memory and distributed caching for optimal performance, providing the best of both worlds.
• 😀 Fusion Cache allows developers to start with in-memory caching and scale up to distributed caching without changing the code.
• 😀 The library automatically handles the interaction between memory and distributed caches to avoid the cons of each individual approach.
• 😀 Developers can easily transition from using basic caching to more advanced setups without needing to modify existing code.
• 😀 One of Fusion Cache’s key features is protection from cache stampede, which prevents excessive load on databases when cache data expires.
• 😀 Fusion Cache offers automatic self-healing for production systems, ensuring cache failures are quickly recovered.
• 😀 With Fusion Cache, a simple configuration change can scale an app from local to distributed caching seamlessly.
• 😀 Fusion Cache improves application performance by drastically reducing request times, from several seconds to milliseconds.
• 😀 The library is easy to integrate, requiring minimal code changes, even for more advanced caching features.
• 😀 Fusion Cache is open-source, allowing contributions from the community, and offers clear and accessible documentation for developers.

Q & A

What is Fusion Cache and why was it created?

Fusion Cache is a caching library designed to simplify working with data access and caching. It was created by the speaker after years of dealing with different types of caches (e.g., memory cache, distributed cache, HTTP caching, CDN, etc.). The goal was to provide a unified and easy-to-use package that improves the developer experience while offering flexibility.

How does Fusion Cache differ from traditional caching solutions?

Fusion Cache is more than just a simple cache. It integrates multiple caching mechanisms (like memory cache and distributed cache) into one seamless solution. It allows developers to use it locally or in memory at first and then easily scale to distributed caching without changing existing code.

What is meant by a hybrid cache in Fusion Cache?

A hybrid cache in Fusion Cache refers to the ability to combine in-memory cache and distributed cache. It uses memory cache as the first level of caching and, when necessary, switches to distributed cache as a second level, ensuring optimal performance across different use cases.

How does Fusion Cache handle the transition from memory to distributed cache?

Fusion Cache allows developers to start with in-memory caching and later switch to a distributed cache (or mix both) with minimal changes to the code. The transition is as simple as plugging in the distributed cache implementation, and Fusion Cache manages the interaction between both caching layers automatically.

What is the 'cache stampede' problem, and how does Fusion Cache solve it?

A cache stampede occurs when multiple requests for the same data go to the database at once because the data is not cached. Fusion Cache solves this problem by ensuring that only one request will go to the database when data is missing from the cache. Other requests are served by the cache once the data is retrieved.

What is the significance of 'micro-caching' in Fusion Cache?

Micro-caching in Fusion Cache refers to caching data for very short periods (e.g., one second). This helps improve performance without worrying about data staleness. It is especially useful for scenarios where data changes infrequently, and even short-term caching offers significant performance improvements.

How does Fusion Cache ensure database calls do not become a performance bottleneck?

Fusion Cache mitigates performance bottlenecks by caching frequently accessed data, reducing the need for repeated database calls. By using the cache, subsequent requests can be served much faster, as the data is retrieved from memory rather than querying the database every time.

What are some key features of Fusion Cache that enhance the developer experience?

Fusion Cache is designed to be easy to use and requires minimal setup. Key features include automatic protection against cache stampedes, phase-safe caching, soft timeouts for slow database calls, and the ability to seamlessly switch between in-memory and distributed caches without changing code.

Can developers contribute to Fusion Cache or learn more about its techniques?

Yes, Fusion Cache is open source, so developers can contribute to the project, share improvements, or learn from the techniques used in its development. The source code is available for review and experimentation.

What performance improvements can be achieved by using Fusion Cache with real databases?

Fusion Cache can drastically improve performance. For example, by using a one-second cache, developers can move from handling only a few queries per second to processing thousands, even when working with a real database like Azure SQL. The caching layer minimizes the load on the database and enhances the overall scalability of the solution.