Azure Functions vs Kafka: What are the differences?
What is Azure Functions? Listen and react to events across your stack. Azure Functions is an event driven, compute-on-demand experience that extends the existing Azure application platform with capabilities to implement code triggered by events occurring in virtually any Azure or 3rd party service as well as on-premises systems.
What is Kafka? Distributed, fault tolerant, high throughput pub-sub messaging system. Kafka is a distributed, partitioned, replicated commit log service. It provides the functionality of a messaging system, but with a unique design.
Azure Functions can be classified as a tool in the "Serverless / Task Processing" category, while Kafka is grouped under "Message Queue".
Some of the features offered by Azure Functions are:
- Easily schedule event-driven tasks across services
- Expose Functions as HTTP API endpoints
- Scale Functions based on customer demand
On the other hand, Kafka provides the following key features:
- Written at LinkedIn in Scala
- Used by LinkedIn to offload processing of all page and other views
- Defaults to using persistence, uses OS disk cache for hot data (has higher throughput then any of the above having persistence enabled)
"Pay only when invoked" is the primary reason why developers consider Azure Functions over the competitors, whereas "High-throughput" was stated as the key factor in picking Kafka.
Kafka is an open source tool with 12.5K GitHub stars and 6.7K GitHub forks. Here's a link to Kafka's open source repository on GitHub.
Slack, Shopify, and SendGrid are some of the popular companies that use Kafka, whereas Azure Functions is used by Property With Potential, OneWire, and Veris. Kafka has a broader approval, being mentioned in 501 company stacks & 451 developers stacks; compared to Azure Functions, which is listed in 27 company stacks and 21 developer stacks.