While the microservices architecture is quickly becoming the preferred design for organizations embracing DevOps, monolithic architecture is still preferred for specific applications. In the middle of the ongoing race between the two strong application systems, this article articulates eight differences to help you decide which one to opt for based on your team’s requirements.Â
As more organizations adopt DevOps to ensure the continuity of software delivery and updates, there has been a gradual shift from a monolithic towards a microservices approach to application development. But while microservices architecture is fast becoming the solution for organizations implementing DevOps methodology, monolithic architecture is still regarded as the best solution for certain applications. To determine which solution is best, let’s examine monolithic and microservices applications systems in terms of the following differences:
Difference Between Monolithic and Microservices Applications Systems
Architectural differences
Monolithic applications consist of a single codebase that interacts with a single database. The application’s client interface, single database, frontend, backend and business logic are incorporated into one codebase. There is only one test and deployment pipeline to maintain. Network latency is not an issue as all function calls are made locally within a single machine.Â
In a microservices system, applications are broken down into separate, small, independent services. Each service is a tiny application with business logic and a variety of adapters. Rather than sharing a database with the other services, each service communicates with its database, tailored to its requirements. Business transactions that affect numerous services must also affect each of the services’ databases. Because each service is entirely separate from the others in the app, it can only communicate via HTTP requests or specific APIs. Microservices are communicated with by user-facing apps, such as mobile, web, and desktop apps, through an API Gateway that handles load balancing, caching, access control, API metering, and monitoring. Because microservices communicate with one another via remote calls, network latency also increases.
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Developing applications
Monolithic application development caters to a single set of technologies, including one operating system, one programming language, and one framework. This makes them simpler to develop than microservices applications at first, but as the application grows, programmers will find it difficult to understand how individual modules interact with the rest of the application.Â
Microservices developers have a wide variety of technology options for building their applications. They can choose whatever technology will provide the best performance for each service. Rather, the difficulty lies in the in-depth knowledge required to identify and develop the services, especially establishing connections between them using separate APIs. Developers will also need an expert domain and container knowledge.Â
Because of its complexity, microservices architecture will require more time and developers to build applications than it takes to build monolithic applications. Since developers need only concern themselves with the services assigned to them, not the entire system’s operation, individual services are faster to develop and easier to understand and maintain than working with a monolithic application.
Testing applications and services
One advantage of monolithic architecture is simplified testing; single automated scripts can be used to test the entire system. Microservices system testing is more complex, especially when each service is built using a different technology stack. Disparate services must be tested individually; thus, to test a service, you need to run your test against that service along with any dependent services.Â
Complexity in the deployment of applications
To deploy a monolithic application, you simply copy the packaged application to a server. The entire monolithic system is uploaded as a single jar/war file so that when changes are made to the application, the entire file must be redeployed, no matter how small. As the application grows, both its deployment and startup times increase.Â
Because of the large number of services and connections between them, microservices deployment is more complex. Each service has multiple runtime instances that need to be configured and deployed independently, making continuous deployment possible. Microservices may be deployed on their own virtual machines or containers. Unlike monolithic deployment, there is no need to stop and redeploy the entire system when a change is made to a particular service.Â
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Scalability
To scale a monolithic application, you simply run multiple copies behind a load balancer. As traffic increases, you may need to deploy instances of the entire application to multiple servers or VMs. However, as a monolithic application grows in size, scaling the application becomes more unwieldy and inefficient. Monolithic applications whose modules have conflicting resource requirements are challenging to scale.Â
With microservices, on the other hand, each service can be scaled independently; for example, if user traffic increases for a certain business function, such as search in an ecommerce app, only the search service needs to be scaled. The services not affected by increased traffic can remain as is. You only need to create more instances of services that require more resources.
Updating to new technologies
To update any component of a monolithic application, the entire application must be redeployed. Monolithic app developers are confined to the original technologies used to develop their applications. If they wish to update their app to new technology or programming language to improve how a particular function works within the application, they would have to start from scratch and reprogram the entire application in the new technology. With microservices applications, each service can be developed using a different technology so that the developer can choose the best technology for the job.Â
Reliability
Because it consists of just one solid codebase, one critical error, such as a memory leak in a single module, can potentially bring down all instances of a monolithic application. Because each microservice works independently, an error in one of them will not affect the others, and those services will continue to run. Also, you are free to make changes to any one service without having to bring the entire system down.Â
Security
Monitoring security is easier with monolithic systems that store data in a single database and transact over a single secure channel, compared to microservices that connect with each other via APIs. Microservices are thus less secure due to their interservice communication over the network.Â
Monolithic or Microservices?
Despite the increasing demand for microservices applications, monolithic architecture isn’t going away anytime soon. Monolithic apps are still appropriate when the app is small such as one developed for a simple eCommerce app or a back-office task, or one that cannot be feasibly broken down into several discrete services. Also, if you are just starting out on a particular app, you may want to build a monolithic app that will take less time to create and validate your application design quickly. Nevertheless, suppose you are looking to build a large app to accommodate lots of users, features, services, and have the flexibility required for continuous improvement and have skilled developers interested in working with the newest technologies. In such a case, microservices architecture may be the better choice.Â
After looking at the differences, which approach would you choose for your organization to build a perfect DevOps environment? Let us know on LinkedInOpens a new window , TwitterOpens a new window , or FacebookOpens a new window . We would love to hear from you!