When AWS announced Lambda–a serverless Function-as-a-Service (FaaS) technology offering–the idea of encapsulating a specific task into a function that resides in the cloud was introduced into mainstream access.
Now, with the rising popularity of microservices, DevOps is waking up the benefits of FaaS where it is used to build and maintain enterprise applications in agile environments. The move to serverless architecture using FaaS is one organizations are now increasingly likely to investigate in 2019.
Given these industry realities, we need to ask ourselves what place will FaaS take in contemporary computing environments and how will its core efficiency proposition enable DevOps to flourish and improve experiences for users at every level?
Back to Focus
First let’s remind ourselves what any FaaS platform really does. It allows us to focus on developing and executing business logic because server provisioning and management is handled automatically at the backend. Developers can deploy applications into a space with zero server administration, yet with the ability to enjoy high availability and high scalability.
The impact for DevOps is immediately apparent.
Developers are able to work in a zone where they are essentially abstracted away from the servers their applications live and breath on. The services developers draw upon are event-driven and eminently scalable. Even if they have to scale by some massively parallel level of magnitude, server-side service optimization is handled at the backend by the FaaS vendor.
At the same time, the cost structure is shifted and operations staff are able to oversee compute billing models based on actual execution of functions, as opposed to being dependent on the physical size of a pre-provisioned cloud server established at best guess size and core optimization parameters for compute, I/O, storage, analytics and so on.
Speedier Implementation
If we have so far looked at the FaaS efficiencies that reside at the backend server-side management element of the equation, let us also turn our attention toward the way FaaS allows developers to reduce the amount of time it takes to deploy code in a new environment.
Adopting a FaaS-centric approach to application architectures allows the developer team to encapsulate specific software tasks into functions, hence the name. For a mortgage calculation application, for example, we can encapsulate functions such as interest rate calculations, payments, length of contract etc., and then place those functions in the cloud on a FaaS platform. The FaaS provider is responsible for the hosting of that function and also looks after the heavy lifting associated with availability and redundancy.
The benefit to developers is a very rapid environment for deploying new code, getting feedback and iterating. The operations benefit is one of hosted happiness as the FaaS provider shoulders a significant administrative burden.
FaaS and microservices are now increasingly viable options in any modern technology architecture and it’s important to distinguish between the two.
Microservices are made up of self-contained elements of business logic designed to perform a very specific job. They are optimized for their single responsibility and can communicate with other services via application programming interfaces (APIs). Further, they can be developed, deployed and scaled independently without impacting other services.
A FaaS-based approach is well-suited for transactional workloads where code is run periodically. This is also a technology that is quicker to establish, as and when needed. A FaaS function might also make a call to other application logic that (in the case of our mortgage example) calculates interest rate and so on.
FaaS Challenges
Like any still-nascent technology, FaaS has its functionality flaws and challenges. The automated nature of foundational provisioning in FaaS is great news, but it’s not a panacea.
Why? For one, DevOps teams will have limits on the debugging capabilities for applications that run on FaaS DNA. Also, functions are instantiated and then de-instantiated as needed, which requires time, especially for a cold start. This process can cause unwanted delays in time-sensitive operations. The transient nature of FaaS also impedes state preservation among dependent functions, which requires careful design considerations.
FaaS is a place where the burden of server resources control has been shifted. But there’s no such thing as a free lunch and this means DevOps won’t be able to interject some level of application monitoring function at the server level itself. You’ll need to know more about your FaaS-based application before you FaaS it up.
We must also remember for any distributed software architecture, there’s an up-front responsibility to design to accommodate the limitations and increasing options available in modern services.
The FaaS Road Ahead
Examples of FaaS now extend beyond AWS Lambda, we can also look to Microsoft for Azure Functions, Google for Cloud Functions, IBM OpenWhisk, Oracle Functions, Fn Project and IronFunctions with its Iron.io platform.
This sector of the software landscape is guaranteed to grow over the coming years. FaaS can be an appropriate option in an overall software architecture, but there are specific limitations, so choose wisely. Observing the evolution of FaaS over the coming years will be a fascinating process.
— Mike Duensing
