6 Disadvantages of Serverless Computing

Serverless computing won't solve your product's problems

<blockquote><p>"Since its migration [to serverless architecture], Coca-Cola has reduced its operational costs by 40 percent and IT ticket volume by 80 percent"</p><p>source: AWS Coca-Cola case study</p></blockquote>

Operational cost reduced by 40%? Ticket volume lowered by 80%? Sounds like a wet dream of virtually every technology-based business.

Such case studies lead us to believe that serverless is the solution to most of our software engineering pains.

But it's NOT.

In this article, we're exploring the hidden costs of serverless computing, and help you decide if it's the right fit for your business.

Disadvantages of serverless computing — Why it might not work in your case

Serverless computing comes at a cost — both monetary and non-monetary. Here's what you need to remeber when considering the switch to cloud architecture.

1. No control over hardware, execution environments, and updates

When you choose serverless computing, you don't manage the server. Thus, you lose control of the server hardware, execution environments and updates. These may become a barrier for certain products.

2. Unstable application performance

Some serverless developers claim that processing times can vary widely between runs, likely due the code may be deployed on a different server with different specifications when restarted.

A known performance problem on some serverless platforms is also Cold Start. This is the time required to call a new container with a specific function if no instance is currently active.

3. Serveless security = sever-sharing causes greater risk

Serverless computing means no dedicated server at your disposal. Serverless providers can therefore run code for several clients on a single server. 

This "multi-tenancy" can negatively affect the security and performance of the application in case of multiple tenant access or incorrect configuration. The result can be data leaks or greater vulnerability to hackers.

4. Usage-based pricing = higher overall costs for long processes

Serverless architectures are billed for code runtime. Therefore, operating applications that require long processes in a serverless infrastructure may end up more costly than traditional infrastructure.

5. Challenging provider switching

Each serverless provider offers a unique set of features. Therefore, using the entire range of backend services from a particular provider makes the relationship between the customer and the vendor long-term. In addition, you should know that configuring a serverless architecture with a specific supplier can make migration challenging.

6. Difficulties in testing and debugging

With traditional application models, developers often install versions of software components locally to test whether the code works before it is uploaded to the production environment. 

Serverless applications may consist of many separate features, therefore replicating the production environment may not be possible.

Debugging also becomes more complicated because developers have no visibility into backend processes. This is also influenced by the fact that the application is divided into many smaller functions.

When not to use serverless computing — Check if you fit any of these 5 cases

Switching to serverless computing will be a BAD choice if:

1. You need to maintain an extensive application with a constant and predictable load — using traditional servers in such a case will tend to be more cost-effective.
2. You need to migrate an older application to a new infrastructure with a different architecture.
3. You need highest-grade security and data protection.
4. You need controlable environment and updates.
5. You need your product to continue operating offline.

Be wary however, as sticking to traditional architecture and skipping the serverless requires:

• a well-developed IT department,
• resources to maintain the backend,
• resources to upgrade your hardware,
• resources to take care of security,
• the ability to resolve problems independently when they arise.

Why companies make the switch — Advantages of serverless infrastructure

Every application implementation model has its flaws. But they need to be weighed against the conveniences a specific technology provides.

In the case of serverless application deployment, these advantages include:

1. Delegated management — the user does not worry about building and maintaining the underlying architecture, as the cloud provider handles everything;
2. Scalability — with serverless computing, you don't need to forecast resource usage — the architecture always provides them to host applications;
3. Lower costs for lighter applications — users pay only for the resources they use.
4. Rapid deployment and updates — as developers don't have to upload code to servers or configure a back-end to release a finished application, and updates can be done one function at a time,
5. Low latency — code can run closer to the end-user by running the application on nearby server.

Serverless infrustructure delegates the management of resources to a cloud service provider and allows engineering teams to focus on the business logic of their application instead of dealing with hardware problems.

Who serverless is best suited for — Check if you fit any of these 5 scenarios

Switching to serverless computing will be a GOOD choice if:

1. You need to process high-latency background tasks — for example, multimedia or data processing.
2. You need the ability to transfer most of the logic to the client.
3. Your product is characterized by unpredictable server load.
4. Your product is growing rapidly and thus require scalability — such as IoT devices.
5. Your product is in the early stages of development and its future is uncertain — think of coding prototypes, MVPs or Proof of Concept.

The products described above will undoubtedly reap all of the benefits of choosing serverless architecture. However, there also are more nuanced cases of projects that could move to serverless with a success.

Switching to serverless computing is worth considering also when you:

• care about scalability because you expect growth and need an environment that meets demand and adapts to your requirements,
• don't have an extensive IT department to maintain and manage servers on an ongoing basis,
• want your employees to have access to data regardless of the time of location,
• want to get your product to market quickly (time-to-market),
• want to pay only for the time the server is in fact used.

Serverless use cases — How Slack, Coca-Cola, and others, benefited from moving to serverless

Serverless computing owes its popularization primarily to the almost universal adoption of cloud computing and microservices. These, combined with the growing demand for more significant innovation, scalability, and agility without significantly increasing costs, drives users toward serverless solutions. That's why we see more and more organizations switiching to serverless infrastructure.

Companies that moved to serverless architecture with great success include:

• Slack — a cloud-based business communication platform, uses a serverless application called marbot to send notifications from AWS to DevOps teams.‍
• HomeAway — Google Cloud Functions based application that lets users research and comment on travel recommendations in real-time (fun fact: it took only few minutes to set up the entire infrastructure and only six weeks to implement the application made by a single developer.)‍
• GreenQ — IBM OpenWhisk based IoT platform that collects key data on pickup times, load weight or location of garbage trucks. The company picked serverless architecture due to fluctuations in demand depending on the number of customers and garbage trucks at any given time.‍
• Coca-Cola — AWS based vending machine software. Since the vending machines communicate with the head office and transmit data for inventory and marketing purposes, the ability to pay for actual consumption significantly reduced the cost of the whole project.

Serverless vs Server vs Cloud computing vs PaaS — Key differences from a business perspective

1. Serverless computing vs cloud computing

Cloud computing is a modern IT technology for processing and storing data on servers outside the local network in a virtual space. Connecting to Cloud Computing means using an Internet connection to access computing resources hosted in data centers managed by third-party providers instead of owning them and keeping them locally.

There are three types of cloud computing:

• IaaS,
• PaaS,
• SaaS.

With the help of cloud computing, developers can run applications in modern data centers with more automation. However, many cloud computing solutions still require a high extent of infrastructure management. Serverless architecture is the subsidiary of cloud computing that eliminates the management part and allows developers to focus on code and business logic.

2. Server vs serverless architecture

Let's now examine what differentiates serverless architecture from servers:

Scalability

Servers are not seamlessly scalable — they have a predetermined storage capacity that is sometimes difficult to scale up, and their resources remain available even when not in use. On the other hand, serverless solutions are fully scalable and allow you to use the computing power and storage you need at any given time.

<span class="colorbox1" fs-test-element="box1"><p>Learn how to achieve scalability with cloud computing. It can be a game-changer for your company, allowing you to handle rapid growth and sudden traffic spikes with ease. </p></span>

Maintenance

Unlike a serverless architecture, a server needs to be set up, maintained, and managed.

Cost

Server usage fees are billed upfront for a defined service. Serverless systems are billed per function call.

3. Serverless vs PaaS

According to Microsoft, Platform as a Service (PaaS) is a complete development and deployment environment in the cloud, including resources to deliver any solution. In this case, the infrastructure is no longer our concern, as the vendor is responsible for providing and maintaining it.

The scope practically coincides with the capabilities of serverless architecture. However, the difference can be seen in scaling — in the case of serverless, scaling works automatically. In the case of PaaS, the user has to configure the scaling parameters himself.

Moreover, unlike serverless computing, PaaS does not offer the possibility to adjust prices depending on usage dynamically. Instead, it provides more control, making testing and debugging applications in a PaaS environment easier.

FAQ — Serverless computing in a nutshell

1. What is serverless computing?

Serverless computing is a cloud services model in which the developer focuses solely on creating the business logic and not on the infrastructure on which it is to be executed. 

Setting up machines, updating operating systems, configuring networks, and scaling applications are all tasks of a given serverless service provider — for example, AWS Lambda, Azure Functions, IBM OpenWhisk or Cloud Functions from Google Cloud.

2. How does serverless computing work?

Serverless computing is a model often used by .NET development companies, in which the cloud provider is responsible for executing a piece of code by dynamically allocating resources. Unlike the traditional model, where you buy specific resources and pay for them even if they are not fully deployed, serverless computing provides the option of paying for the resources used. 

The term "serverless" is somewhat misleading because it implies the absence of servers. Of course, servers do exist, but developers don't have to deal with them. As a result, they can entirely focus on developing applications instead of worrying about configuring, scaling and securing virtual machines, servers or containers.

Serverless computing is sometimes referred to as "Functions as a Service".

3. What are the benefits of serverless computing?

Key advantages of serverless computing include:

• no need for server management — everything is on the serverless provider's side,
• billing for actual usage — which in many cases can reduce costs,
• scalability — applications built on serverless architecture are easy to scale, which ensures their efficient operation even with increasing load,
• rapid deployment and updates — as developers don't have to upload code to servers or configure a back-end to release a finished application, and updates can be done one function at a time,
• eliminating latency — code can run closer to the end-user by running the application on nearby servers.

Next read: Microservices vs monolith - is the choice always so obvious?

Don't believe the hype.

Explore the trade-offs between microservices and monolithic architecture and learn why a modular monolithic approach may be more efficient for smaller projects. Discover the factors to consider when deciding on the right architecture for your project and how to transition from a modular monolith to microservices if needed.

Expand your knowledge by reading this use case: Sometimes a Monolith Is Better Than Microservices.