Fission vs Knative: What are the differences?

Key Differences between Fission and Knative

Fission and Knative are both serverless platforms designed to simplify application development and deployment. However, there are several key differences between them.

1. Flexibility of Language Support: Fission offers greater flexibility when it comes to language support, as it allows developers to write functions in any programming language, including popular choices like Python, Node.js, and Go. On the other hand, while Knative provides support for multiple languages, it focuses primarily on Docker containers, limiting the language choices available.

2. Deployment Mechanism: Fission uses a "hot function" model where functions are kept in a running state, ready to be executed when an event occurs. This allows for faster response times and lower latency. In contrast, Knative follows a "cold start" model where functions are scaled to zero when not in use and require some time to start up when an event triggers their execution.

3. Scalability: Knative offers more advanced and flexible scaling capabilities compared to Fission. Knative's scaling is based on the number of incoming requests, allowing for horizontal scaling of functions as per demand. Fission, while it provides auto-scaling based on CPU usage, does not have the same level of granular control as Knative.

4. Integration with Kubernetes: Both Fission and Knative are built on top of Kubernetes but have different levels of integration. Knative provides a more seamless integration with Kubernetes, making it easier to manage and deploy functions as Kubernetes resources. Fission, while it also runs on Kubernetes, has a separate controller and a custom resource definition to manage functions.

5. Eventing and Messaging Support: Knative has built-in support for eventing and messaging through its eventing subsystem, which allows for easy integration with various event sources and messaging systems. Fission, on the other hand, lacks native eventing support and requires additional components or external tools to achieve similar functionality.

6. Community Support and Maturity: Knative has a larger and more active community compared to Fission, which translates into better support, more frequent updates, and a wider range of available resources. Fission, while still actively maintained, may have a smaller community and fewer resources.

In summary, Fission and Knative differ in terms of language support, deployment mechanism, scalability, Kubernetes integration, eventing support, and community maturity. Choosing between the two depends on the specific requirements and priorities of the application being developed.