5 Reasons Not to Use Serverless Computing

While serverless computing is widely favored, it’s important to acknowledge its drawbacks, as it might not suit every aspect of every workload optimally.

erverless computing stands as an enticing solution, celebrated for its remarkable attributes: scalability, cost efficiency, and the simplified deployment process it affords engineers. Yet, within the fervor of extolling these benefits, the platform’s inherent drawbacks often evade comprehensive discussions.

In recognizing this disparity, it becomes imperative to embark on a deeper exploration of why the blanket adoption of serverless computing might not universally constitute the optimal strategy for software deployment. While the advantages of serverless functions are undeniable, an astute evaluation necessitates a nuanced understanding of their limitations.

There’s a lot to love about serverless computing. It’s scalable. It’s cost-efficient. It minimizes effort required from engineers to set up and deploy software.

But serverless comes with some distinct downsides, too — and they’re easy to overlook during discussions of all of the benefits that serverless has the potential to offer.

Related: How to Choose Between Serverless, VMs, and Containers

With that reality in mind, let’s take a sober look at the reasons why serverless computing isn’t always the right way to deploy software. As you’ll learn below, although serverless functions certainly have their benefits, understanding their limitations is critical for making informed decisions about whether serverless is actually the right way to go.

What Is Serverless Computing?

Serverless computing is a cloud computing execution model where the cloud provider dynamically manages the allocation of machine resources. In this model, the user doesn’t have to provision or manage servers explicitly. Instead, the cloud provider allocates resources as needed to execute a particular piece of code or function.

The term “serverless” can be a bit misleading; it doesn’t mean that there are no servers involved, but rather that as a user, you’re relieved from dealing with the server infrastructure. The infrastructure management tasks, such as server provisioning, scaling, and maintenance, are abstracted away from the user, allowing them to focus solely on writing and deploying code.

This model operates on the principle of Function as a Service (FaaS), where applications are broken down into smaller functions that can be executed independently in response to events or triggers. These functions are executed in stateless compute containers that are created on-demand and scaled automatically, depending on the incoming workload.

Serverless computing offers several advantages, including:

  1. Scalability: It automatically scales to handle varying workloads, ensuring that resources are allocated as needed without the user’s intervention.
  2. Cost Efficiency: Users are charged based on the actual resources consumed by their functions rather than paying for idle server time.
  3. Simplified Deployment: It simplifies the deployment process, as developers can focus on writing code without concerning themselves with server management tasks.
  4. Faster Development: With a focus on smaller functions, development cycles can be faster and more focused, allowing for rapid iterations and deployments.
  5. High Availability: Cloud providers often ensure high availability of serverless architectures, reducing the risk of application downtime.

Despite these advantages, serverless computing also comes with its limitations, such as potential vendor lock-in, challenges in managing stateful applications, and concerns about performance in certain use cases.

Overall, serverless computing represents a paradigm shift in how applications are developed, deployed, and scaled in the cloud, offering agility, cost-effectiveness, and scalability for various use cases.

The Disadvantages of Serverless Computing

In certain instances, the advantages promised by serverless computing are offset by the drawbacks inherent in this approach.

The allure of serverless computing lies in its apparent cost efficiency, where payment is solely for active workload time. Yet, this apparent advantage can be misleading, as the per-minute cost of serverless computing tends to exceed that of running an equivalent workload on a virtual machine (VM).

Consequently, despite its on-demand payment structure, serverless computing might result in higher overall costs, particularly for workloads characterized by continuous activity.

Key Considerations

  1. Cost Discrepancy: Serverless’s billing model, while attractive in theory, often translates to higher expenses compared to other cloud services, especially when dealing with consistently active workloads.
  2. Vendor Lock-In Risks: Each serverless platform operates uniquely, complicating workload migration across different providers. This contrasts with other cloud services, where differences are less pronounced, reducing the risk of lock-in.
  3. Startup Time Challenges: Despite the promise of on-demand functionality, serverless often experiences delays, notably in “cold starts” when the code hasn’t been recently executed. For time-sensitive workloads, like real-time data processing, these delays can be detrimental.
  4. Limited Configuration Control: The convenience of relinquishing server management in serverless setups comes at the cost of minimal control over the environment. Users are restricted to the operating system and runtime settings provided by the serverless provider.
  5. Management Overhead: Often, a hybrid approach is adopted, leveraging serverless for specific functions while hosting other parts on a VM. While this optimizes costs, it introduces complexities in managing multiple cloud services within the same workload, increasing management overhead.

Balancing Act

Deploying a combination of serverless functions and traditional hosting models enables users to optimize the benefits of each while mitigating their respective drawbacks. This approach, while efficient, demands adept management and orchestration of diverse cloud services, balancing the benefits against the complexities.

In essence, while serverless computing offers apparent advantages, it’s crucial to weigh these against the potential drawbacks, especially in scenarios demanding consistent performance, extensive configuration control, or seamless workload management. This nuanced evaluation allows for informed decisions tailored to specific workload requirements and optimization of resources.

Conclusion: Serverless Is Great, but Only Sometimes

It’s important to make clear that I’m not here to outright discourage the use of serverless computing services. Instead, I advocate for a strategic approach when considering and implementing serverless solutions. While there’s been significant buzz and enthusiasm surrounding serverless computing in recent years, it’s crucial to adopt a balanced perspective that includes an acknowledgment of its genuine limitations.

In essence, while acknowledging the remarkable potential of serverless computing, a cautious and strategic approach ensures its optimal utilization. It’s not about dismissing its merits but rather embracing them judiciously in alignment with the unique demands of a given workload or project. This approach fosters efficient and effective deployment while mitigating the downsides often associated with serverless computing.