Microservices vs. Serverless: Which is better for your business?

Serverless and microservices are both significant topics in the field of cloud-based computing. Although microservices and serverless functions generally go hand in hand, they're distinct technologies that play various functions in the modern software environment.

This article will provide an overview of what serverless and microservices are, what they connect, what they have in common, and the reasons you might or might not choose to implement serverless microservices.

What are microservices?

"Microservices" is a term used to describe a system of services. "Microservices" is an architectural design pattern where applications are broken down into a set of smaller services (hence the name "microservice"). Microservices architectures are a different type of monolith (meaning applications in which everything functions as a single unit).

For a basic example of a microservices-based application, think of a shopping app that lets customers look for items, add them to their carts, and then finish their purchase. The app could be developed into a set of distinct microservices:

• A front-end interface for applications
• A text here search engine that searches for products within databases based on the input of users to create a query.
• A service for product details that provides additional information on the products when users click.
• The shopping cart is a service that keeps track of the items users add to their carts.
• A service for checkout that manages payments.

This is only an illustration. In real-life microservices, applications are developed in a variety of ways. There are no strict guidelines on how functionality for applications is distributed across various microservices.

There's not any rule that says you have to provide a certain number of services to be able to be considered examples of microservices. Technically speaking, you can use just a few of these services and label the app a microservice, but most developers will include at least some microservices within every application.

While the ideas that underlie microservices have been around for a while (as demonstrated by the hype around microkernel in the 1990s and 1980s as well as the SOA trend in the 2000s, for instance), it's only been in the past 10 years or since that microservices have become more sought-after. This is due to the flexibility and scalability that microservices provide to applications that run in cloud-based distributed environments. When you're running multiple instances of your application on several servers, microservices make sure that you can spread the workload more evenly by running multiple microservices on various servers.

Microservices also increase the performance and reliability of your application by spreading the footprint of your application: if one of your microservices is not working, the rest of the application will continue to function, and users won't be completely shut out. Additionally, since microservices aren't as big as entire applications, it's easier to create an entirely new microservice to replace a failed one (or to increase capacity if the application's load grows) as opposed to having to load the entire application.

Serverless

Serverless refers to a type of model that allows application code to be executed on-demand, in response to triggers that application developers can configure ahead of time.

The code running in this manner (which is referred to as serverless functions) could be a complete application. It is, however, more usual to make use of serverless functions to provide specific units of application functionality.

A typical usage for serverless is running an application that can resize pictures uploaded by customers. In this instance, developers could install triggers that would trigger the serverless function each time a user uploads an image into the app. The serverless function would perform its task and stop when it's finished.

The major advantage of serverless is that it provides a cost-effective method of running programs that don't need to run indefinitely. In the absence of serverless, you'd need to keep every part of your application running at all times, and this would consume resources. Serverless capabilities let you make certain elements in your app only run when they're required.

So, an application's frontend generally isn't an ideal candidate for a serverless application since it has to be running continuously to ensure that users are active. However, an authentication service that is only used often could be a suitable option for serverless.

Serverless is also a benefit of simpler configuration and deployment. Instead of having developers create the entire operating system, Serverless allows them to upload the features they want to run, set the triggers and then end the day.

Similar to microservices, the ideas that led to serverless were around for quite a while. However, serverless didn't emerge until the cloud-native period. In particular, the introduction of Lambda (Amazon's serverless platform) in 2014 kicked off the modern serverless age. Today, all major cloud providers provide servers that are serverless. Third-party serverless frameworks such as Kubeless and OpenFaaS, which can be run on cloud IaaS infrastructure or on-premises, are also available.

Serverless Microservices

Therefore, serverless and microservices are two distinct types of technologies. Microservices can be used to develop an application and serverless is the method for running an app (or the component of an application).

However, microservices and serverless are quite closely linked. They are not only commonly used in cloud-based environments and environments, but serverless computing functions can be used for hosting microservices.

Also, you can create a "serverless microservice" by creating the code for a microservice and configuring it to be run as a serverless service. For all the reasons discussed in the previous paragraph, any microservice that is required to run for only a few minutes can be a suitable candidate for an implementation model for microservices that is serverless.

Microservices and servers are alike in that they both require similar methods of management and control of their operations. The more serverless or microservices functions you incorporate into your system, the more moving parts you need to keep in mind and the more powerful monitors and tools for managing logs will need to be.

Distinctions between Microservices and Serverless

It's not to say that serverless and microservices always work in tandem. It's not common to run every microservice within an application in serverless functions. In general, we've talked about the possibility of having microservices (like frontends for apps) that need to be running continuously, and they aren't a good fit in the serverless framework. It is better to deploy them in containers.

There's no requirement to implement a microservices framework to benefit from serverless architecture capabilities. Nothing is stopping you from installing a monolithic app on serverless platforms, though it's difficult to envision the many scenarios in which this could provide significant advantages. It's not possible to reap the efficiency serverless provides when you're running one monolith, and you can't distinguish the units of your application that have to be running continuously from those that are only needed for certain periods.

It is important to note that serverless environments can comprise a myriad of serverless functions, some of which could be shared with several applications. (Again, going back to the instance of a serverless program that resizes images, it's possible that you could have several applications that require that functionality, so you'd be sharing the function across the applications.) However, it isn't common (though certainly not difficult) to have many microservices in one application. It's not normal to use the same microservice across several applications unless it's a service that provides additional functionality (like collecting logs) instead of the core functionality of an application.

Some observers also suggest that serverless remains less advanced than microservices. However, it is debatable and varies to a degree on the way you define microservices and serverless. Both technologies have existed for a long time to this point, and it is difficult to argue that either one is sufficiently mature to be used in production.

However, it is possible to claim that the software used for serverless functions isn't as well-developed as it is for microservices. Many solutions can manage and monitor microservices-related applications. Monitoring for serverless and log management is harder to locate due to the reality that the market for servers is still fragmented. The serverless platforms aren't identical, and they all run various languages, and it isn't possible to drag and drop a serverless function from, for instance, AWS Lambda into Azure Functions without reconfiguring it at a minimum. Therefore, the tools for monitoring and managing serverless are largely platform-specific. In this way, at the very least, serverless is a little less well-developed than microservices.

But, PerfectionGeeks does support log analysis and management for microservices architectures as well as serverless functions. It's simple to grab logs from a serverless system such as Lambda and transfer the logs into PerfectionGeeks for analysis. It is also possible to manage the logs of any microservices environment with PerfectionGeeks, just as you would use a monolith.

Conclusion

If you are a fan of analogies, you could consider that serverless is like French fries, and microservices are like ketchup. They go well with each other, but they don't necessarily have to be paired. You can enjoy French fries and mustard, or mix your ketchup and hamburgers, the same way you can implement microservices with serverless functions or make use of serverless to run applications that aren't microservices in the traditional sense.

If you're not a fan of analogies, think of it in this manner: Serverless is one method to host microservices, but it's not the only method. You can't manage and deploy microservices in the same manner as servers do. Both of these technologies have advantages to cloud-native computing. However, they are not able to solve the same kinds of issues.