Pros and cons of serverless computing

Here is a quick look at some of the key benefits that you, as a developer, can attain with the help of serverless computing:

• No ware to manage: Perhaps one of the biggest reasons for the hype about serverless computing is the fact there is absolutely no hardware or software to manage. The management of the serverless computing environment all the way from the underlying hardware to the OS, to even the application's platform layer, is managed by the cloud provider itself.
• Faster execution time: Unlike your standard cloud instances, which generally take a good minute or two to boot up, functions, on the other hand, spin up very quickly, mostly in a matter of seconds. This could be due to the fact that the functions are made to run on top of a containerized platform.
• Really low costs: Since there is virtually no opex involved with serverless computing, it is fairly cheap, even when compared to hosting and managing instances in the cloud. Also, the pricing model for serverless computing is a little different from that of your traditional cloud pricing model. Here, you are generally billed on the duration of your function's execution and the amount of memory it consumed during its execution period. The duration is calculated from the time your code begins executing until it returns or otherwise terminates and is rounded up to the nearest 100 ms.
• Support of popular programming languages: Most cloud providers that provide serverless computing frameworks today, support a variety of programming languages, such as Java, Node.js, Python, and even C#. Azure functions allows the use of F#, PHP, Bash, Batch and PowerShell scripts in addition to the few mentioned.
• Microservices compatible: Since serverless computing functions are small, independent chunks of code that are designed to perform a very specific set of roles or activities, they can be used as a delivery medium for microservices as well. This comes as a huge advantage as compared to hosting your monolithic applications on the cloud, which do not scale that effectively.
• Event-driven applications: Serverless functions are an ideal choice for designing and running event-driven applications that react to certain events and take some action against them. For example, an image upload operation to a cloud storage triggers a function that creates associated thumbnail images for the same.

Feeling excited already about giving serverless computing a try? Hold on! There are a few cons to serverless computing as well that you should be aware of before we proceed further:

• Execution duration: Serverless functions are designed to run for short durations of time, ideally somewhere under 300 seconds only. This is a hard limit set by most cloud providers, however, there are a few workarounds to this as well.
• Stateless: Serverless functions are purely stateless, which means that once the function completes its execution or is terminated for some reason, it won't store any data locally on its disk.
• Complexity: The smaller you make things, the more complex it's going to become. Although writing functions that perform very particular tasks is a good idea, it can cause complexity issues when you view your application as a whole system. A simple example can break one large application into some ten different functions such that each perform a specific task. Now you need to manage ten different entities rather than just one. Imagine if you had a thousand functions instead.
• Lack of tools: Although serverless computing is all at its hype, it still doesn't provide a lot of out-of-the-box tools for management, deployment, and even monitoring. Most of your monitoring tools that you use today were designed for long-running, complex applications; not for simple functions that execute in a mere seconds.
• Vendor lock-in: With each cloud provider providing its own unique tool sets and services around serverless computing, you often tend to get tied down to a particular vendor. This means that you cannot change your cloud provider without making some changes to your functions as well.

With these key points in mind, let us get to understanding and learning a bit more about the core serverless computing service that this book is all about--AWS Lambda.