Today we have many architectures for building our projects, from N-tier layer, monolithic, microservice, and serverless. So which architecture should we choose to deploy the project? And what are its strengths? This article will compare today’s popular models: Microservices, Monolithic, and Serverless.
Monolithic Architecture
Monolithic applications are all-in-one apps. Although they are old-fashioned, but still useful.
Comparing with Microservices and Serverless, a Monolithic application typically has all the features in a single codebase written in a single programming language and technology stack.
Microservices and Serverless separate the front-end and back-end also functionalities. Still, Monolithic applications built with a single entity with all functionalities, both front and back, are not very popular, but it is still an excellent way. In addition, monolithic apps have many advantages for specific situations.
- If you need your application fast, have good availability, and freely serve static content to whoever wants to consume it. (Such as WordPress for Blog)
- Apps based on monolithic architecture are typically faster, easier, and cheaper to build as they don’t involve synchronizing and connecting multiple moving parts.
Monoliths are ok for some applications, but for more complex systems, you may want to go ahead and break it down into microservices.
Advantages of Monolithic Architecture
1. Faster, easier, and cheaper to build
In most engineering contexts, the best solution is the simplest way to achieve the required result reliably. Software engineering is no different, and monolithic apps are faster, easier, and cheaper to build than those based on more sophisticated architectures. A monolithic architecture might be a good choice if it meets your needs and does not hinder your success.
2. Convenient testing and production processes
It is much easier to test a monolithic app than a microservices or Serverless app. You can start and test an application on the developer’s computer or staging environment and apply a standard deployment process to check on changes before putting it into production.
3. Simple infrastructure
Monolithic apps use a single server for their front end, back end, and database, simplifying infrastructure requirements. But Microservices and Serverless need complex infrastructure requirements. A content delivery network such as Cloudflare can boost monolithic web apps’ performance, reliability, and security.
4. Monitoring
A simple infrastructure brings the additional advantage of easier monitoring.
5. Straightforward transaction controls and data integrity
The fact that monolithic applications usually use a single database for storage means they benefit from straightforward transaction controls and different mechanisms and data integrity provided by a relational database (RDBMS).
Disadvantages of Monolithic Architecture
1. Large codebase
Monolithic Architecture means a single codebase. If the codebase becomes large, it can be difficult for developers to read and understand, making it more challenging to integrate new developers into a project.
2. Updates can be challenging.
Updating a monolithic application means rebuilding and redeploying the entire codebase.
3. High level of dependencies
Components depend on each other in a single codebase, so modifying one module or service can easily affect others. Foreseeing the impact of a minor change in one part on the whole app is challenging. Therefore, developers have to re-test the entire codebase after each update.
4. Lack of flexibility
With a Monolithic Architecture, you must use the same tech stack for the whole application. You cannot choose a different or better technology for specific services. This limits your options and flexibility.
5. Scalability
If your monolithic app becomes very popular and needs more features and capacity, you may need to switch to Microservices or Serverless architecture. Monolithic applications are not good at scaling up.
Microservice Architecture
Microservices are smaller pieces of a more extensive app. They offer more flexibility and performance but at a higher cost and complexity.
Microservices are an architectural pattern that arranges an application as a collection of loosely-coupled, fine-grained services communicating through lightweight protocols. This differed from a monolith, an application written in one language and operated together as one code unit.
Microservices architecture is a contemporary approach to developing software applications from a collection of individual modules (services). Services can focus on one task (payment, shipping, etc.) or business function and leverage the best technologies for each purpose.
Microservices architecture is far from new as a concept. The microkernel approach of the 80s and 90s and service-oriented architecture (SOA) that became common in the 2000s also broke applications down into components. However, the rise of cloud-based environments and the need to run applications in a distributed way across multiple servers properly established the modern microservices approach.
As software systems became more complex, it was also increasingly important to spread risk by decoupling services so that one microservice failing doesn’t take down the whole application.
Advantages of Microservice Architecture
1. Iterative development
Microservices-based software architecture works well with agile software development processes that use iterative development.
- We can develop new features and functions more easily and safely by splitting an operational application into independent services.
- Enables parallel work on different services by different teams and simplifies the integration of new team members.
2. Flexibility
As already mentioned, one is that the architectural approach means different teams can develop different services relatively independently of each other.
3. Tech stack freedom
Another big plus of microservices is the architectural approach offers significant freedom in tech stack choices. A microservices architecture’s loosely coupled services allow for much greater freedom in tech stack choices. The development team can, in theory, create individual services with very different tech stacks.
4. Availability
One of the most significant advantages of a microservices architecture is that loosely coupled services lead to a more robust application and higher availability. In addition, if one service fails, the loose coupling should mean it doesn’t affect the rest of the application, which will continue functioning for users.
5. Scalability
Another benefit of a microservices architecture’s independent services is that they make scaling apps easier. Its modular nature makes it easy to work on and add new features and functionalities to a live application. While the upfront cost of investing in a microservices architecture is higher, it can be cheaper to scale than a monolith app due to combining the strengths already mentioned.
6. Improved performance
Being able to split services and loads across multiple servers can enhance performance.
Disadvantages of Microservice Architecture
1. Complexity
A microservices architecture adds more complexity as multiple services must work together as a single software system. Also, you must set up that complex infrastructure for services on different servers.
2. Testing complexity
While smaller codebases mean, it is much easier to test individual microservices, testing each service individually can add significant complexity as an application scales. In addition, testing and maintaining communication between services adds a further layer of complexity.
3. Higher upfront costs
While trying to scale a monolithic application significantly can be a nightmare that quickly sees both direct development and opportunity costs mount up, a microservices architecture does involve higher upfront costs.
Each microservice requires its developers (though it’s probably a single team responsible for multiple microservices), a tailored source code management system, a testing process, and scripts facilitating automated deployment. That all adds up to higher upfront costs.
4. DevOps requirements
A distributed system like microservices requires skilled orchestration, usually involving Kubernetes and other DevOps tools and processes. That means you will probably need to employ or contract at least one DevOps engineer. That will add to costs, and DevOps specialists can be hard to recruit with demand soaring.
Serverless Architecture
Cloud-native development. You don’t manage the server that runs your application.
Serverless architecture lets you create and run applications and services without managing infrastructure. Instead, your cloud provider(AWS, GCP, AZURE, etc.) handles all server administration, even though your application runs on servers.
Serverless is closely related to microservices. Many modern applications combine serverless and microservices. Like microservices, the concepts that underpin serverless have been around for a long time but have become a fixture in mainstream software development since the rise of cloud computing.
Serverless architecture has been around for more than a decade,
Amazon introduced the first mainstream FaaS platform, AWS Lambda, in 2014. Currently, most developers still use AWS Lambda to build serverless applications. Still, Google and Microsoft have their own FaaS offerings, called Google Cloud Functions (GCF) and Azure Functions.
Serverless vs. Microservices
In one sentence, the difference between microservices and serverless is that the former is a way to design an application, and the latter is a way to run all or part of an application. That’s the key to their compatibility. It’s possible to code and run a microservice as a serverless function.
- The serverless architecture consists of a set of functions rather than services.
- A service runs continuously, but a function has a lifecycle – it starts, runs, does its job, and then stops.
- Serverless functions only run on demand, which can save a lot of resources.
- In serverless architecture, the serverless platform provider takes care of infrastructure provisioning.
- The development team doesn’t have to configure the entire software system.
- Functions are uploaded to the serverless platform, the triggers that will launch them are configured, and the provider takes care of the rest.
- Microservices would usually be used for parts of an application that need to run constantly, like the front end of a user application.
- Serverless works best for functions used occasionally and for a limited time.
- Serverless functions hosted on a serverless platform can also be used across multiple applications.
Serverless architecture is less flexible than microservices. Serverless providers only natively support specific programming languages, frameworks, and tools; while there are workarounds, they can be complicated and problematic. And every serverless platform supports different technologies, meaning running the same function with different providers is impossible without reconfiguring it to some extent.
Serverless tooling is also generally considered less mature than it is for microservices. For example, serverless monitoring and log configuration tools are limited.
While entire applications are built of serverless functions in a pure serverless architecture, in most cases, it makes the most sense to run certain services as serverless – those that are not in permanent use and have a relatively short run-time, especially if that run-time is resource intense.
The future of serverless architecture is probably a technology that complements, rather than replaces, microservices.
Advantages of Serverless Architecture
1. Flexibility
Breaking applications down into serverless functions offers similar flexibility advantages as microservices.
2. Cloud computing costs
Calling and killing functions, so they only run for as long as required, can potentially lead to significant savings in cloud computing overheads compared to them being permanently available.
3. No need to provision infrastructure
The serverless provider providing the cloud infrastructure serverless functions run on means the software development team has one less thing to worry about and can focus on coding the application itself.
4. Scalability
As with microservices, the modular nature of serverless makes it easier for software development teams to scale applications as new functions can be worked on independently and added incrementally to the live app.
5. Reliability and availability
Again, as with microservices, an app being split into loosely coupled functions means there is a far lower level of dependence across functions than would be the case in a monolithic architecture. So if one function fails, the app should keep working otherwise. The provider taking care of underlying infrastructure also further reduces potential points of failure.
Disadvantages of Serverless Architecture
1. Complexity
Being broken down into independent functions means it still consists of multiple, smaller moving parts, making it more complex than a monolithic approach.
2. Tech stack limitations
Serverless platforms only support specific languages, frameworks, and tools, which means you are limited to coding functions using those supported by your provider.
3. Vendor lock-in
Applications that are entirely serverless or include serverless functions are relatively tightly tied to the provider platform they were built for because no two are the same and interchangeable. Of course, it’s far from impossible to reconfigure serverless functions for a different provider’s platform. However, doing so for an extensive, complex application involving numerous functions would be a significant undertaking.
4. Immature tooling
Compared to traditional monolithic and microservices, it is often argued that the tooling available to support serverless development and maintenance is immature. For example, a lack of good monitoring and log configuration support is regularly highlighted. However, with serverless architecture quickly gaining traction, tooling will inevitably mature.
Conclusion
Monolithic architecture is ideal for small applications due to its rapid development, ease of testing and debugging, and low cost. However, as the system grows, it may impede business and should evolve into a different form.
Using microservices has many advantages. You can build applications that are easier to change and manage without causing errors. You can also work with your team more smoothly on a project, no matter how much experience you have—from beginners to experts.
Serverless describes how the program works inside, while Microservices describes how to design your application outside. A serverless application can follow or ignore the ideas of microservices (but this is often the recommended way to do it). Any, some, or none of the microservices in a microservices design can use serverless technology.
Serverless is a great way for businesses to make scalable, light apps faster. But Microservices can work better if your apps have many long-running, ongoing tasks. In a mixed design, developers can use Microservices for most requests but give some fast jobs, like database storage, to serverless actions.
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