Apache OpenWhisk vs Azure Functions: What are the differences?

Apache OpenWhisk and Azure Functions are both serverless computing platforms that allow developers to build and run event-driven applications without the need to provision or manage the underlying infrastructure. While both platforms have similar goals, there are several key differences between Apache OpenWhisk and Azure Functions that set them apart from each other.

1. Language Support: One key difference between Apache OpenWhisk and Azure Functions is the language support they offer. OpenWhisk supports a wide range of programming languages including JavaScript, Python, Swift, and PHP. On the other hand, Azure Functions offers support for languages such as C#, Java, JavaScript, PowerShell, and TypeScript. This difference in language support allows developers to choose the language they are most comfortable with for building their serverless applications.

2. Event Sources: Another difference between OpenWhisk and Azure Functions lies in their event source integrations. OpenWhisk allows developers to trigger functions based on various event sources such as HTTP requests, timers, message queues, and database updates. In contrast, Azure Functions provides a broader range of event source integrations including HTTP requests, timers, message queues, databases, IoT devices, and more. This wider range of event sources in Azure Functions gives developers more flexibility and options when it comes to triggering their serverless functions.

3. Scaling Model: In terms of scaling, there is a slight difference between OpenWhisk and Azure Functions. OpenWhisk scales the execution environment by creating new instances of the runtime to handle increased load. This means that each individual function is scaled independently based on its usage. On the other hand, Azure Functions uses a more granular scaling model called "Consumption Plan" where functions are automatically scaled based on the number of incoming requests. This scaling model in Azure Functions allows for more efficient resource utilization, as it can dynamically scale the entire function app rather than each individual function.

4. Development and Deployment: OpenWhisk and Azure Functions also differ in terms of development and deployment options. OpenWhisk provides a command-line interface (CLI) as well as a web-based graphical user interface (GUI) for managing functions and deployments. It also allows developers to deploy functions using a variety of methods including direct code upload, packaging functions into containers, or using a source code repository. Azure Functions, on the other hand, provides a rich development experience through its integrated development environment (IDE) in Azure Portal. It also offers seamless integration with Azure DevOps for continuous integration and deployment of serverless functions.

5. Pricing Model: OpenWhisk and Azure Functions have different pricing models. OpenWhisk pricing is based on the number of invocations, compute time, and memory usage, with separate pricing for each programming language. On the other hand, Azure Functions offers a consumption-based pricing model where users only pay for the actual number of executions and the associated resources used by the function. This pay-per-use pricing model in Azure Functions can be more cost-effective for applications with variable workloads and intermittent usage patterns.

6. Community and Ecosystem: The last key difference between OpenWhisk and Azure Functions lies in their respective communities and ecosystems. OpenWhisk is an open-source platform that is supported by a vibrant community of developers and contributors. It has a wide range of community-built integrations and extensions, which can be beneficial for developers looking for additional functionalities and customizations. Azure Functions, being a part of the larger Azure ecosystem, benefits from the extensive set of Azure services and integrations available. It also has a strong community and marketplace, offering pre-built templates and extensions that can expedite the development process.

In Summary, the key differences between Apache OpenWhisk and Azure Functions lie in their language support, event source integrations, scaling models, development and deployment options, pricing models, and community ecosystems.