The Microservices architecture is undeniably easier to implement and offers more advantages as compared to the traditional monolithic app development approaches. However, the deployment procedure requires more discipline and effort to design, build and effectively manage. Just as every technology comes with a learning curve, the microservice architecture also poses some challenges that businesses need to overcome, as they adopt the microservice architecture. Although many businesses have already been experiencing the benefits of microservices, those starting from scratch must also know the challenges involved in the process of creating and using a microservices application for their business.
Challenges include:
Achieving Data Consistency
In the case of microservice architecture, every service handles its data independently, across its data stores, causing a problem of data redundancy. For example, when one service stores data for specific transactions, the same data may get stored across various services for reasons like analysis, reporting or even archiving. Moreover, when multiple services are tied to the same database, alterations in one service may cause a cascading effect across multiple linked services. This negates the purpose of having independent service functions.
To overcome this challenge, one does not require every microservice to have a separate physical database. Every service must, however, have complete ownership over its data. Microservices would require every type of database: NoSQL, graph, and in-memory. Therefore, having a relational database would not bring out the desired results in a microservice architecture.
The Problem of Inter-Service Communication Breakdown
The various microservices that rely on each other within an application software communicate using well-defined APIs. However, these do not share the same technology stacks, frameworks, or data libraries. For smooth internal communication, developers are required to set up infrastructure layers that enable effective resource sharing across multiple services. The method of communication and interactions need to be explicitly defined. It demands principles for security, serialization, error handling, requests, etc. Therefore, a poor configuration can lead to increased latency, thereby invalidating the purpose of microservices.
As a result, companies deploying microservices architecture would require some form of service mesh capabilities like reliable CI/CD servers, application performance management tools, configuration management platforms, etc. to ensure effective internal communication, among services.
Need for Expert Teams
Transitioning to a microservice architecture requires expert teams who have experience working with distributed systems. Switching to microservices could fail if the organization has an ill-prepared design and development team. Moreover, the team also needs to promptly coordinate with independent teams involved in developing the stand-alone service functions. To cover the whole cycle and get the microservice architecture smoothly running, all teams must apply concepts like CAP, BASE, functional interfaces, CQRS, and sagas.
To accomplish error-free integration and data persistence, teams also require a holistic understanding of concepts like persistence ignorance, polyglot persistence, and event-driven messaging. Lastly, organizations also need developers with a good understanding on how to build and maintain polyglot microservices using complex CI/CD pipelines.
Difficulty in Maintaining Microservices
Microservices bring flexibility by allowing the use of diverse programming languages and different technological bases, within a single business application software. When the software transitions into maintenance mode, the flexibility and ease may end up being shadowed by high maintenance costs due to the diverse tools and technologies used.
Therefore, to prevent such costs, developers must ensure that a microservice failure should not bring down the entire system. All design rules must be strictly followed and checked with new versions of microservices before they are updated to prevent any form of breakdown, affecting the entire application.
Operational Complexity Leading to Poor Network Management
An application software designed using the microservices architecture approach entails a multitude of modular services. In this case, managing all these services would require some serious, disciplined efforts to avoid failovers and ensure that the system is resilient to changing business demands. If there is a sudden spike in application usage, coordination of services becomes even more challenging. Moreover, if a single microservice fails, it may cause a cascading effect on the remaining services.
Thus, developers must ensure that each of these microservices are resilient in themselves, without relying on other services. Sophisticated management tools should be used for automated provisioning, making the entire system bullet-proof and agile.
By deploying and using the right kind and quality of automation software, tools and technologies, CI frameworks and expert staff, every business can overcome most of the above-mentioned challenges, in their quest to adopt the microservice architecture. With the right support and knowledge, every business having large applications can successfully break their infrastructure down into smaller components, thereby bringing flexibility and potential for higher scalability.
Need for rapid provisioning and app Deployment
As microservices enable incremental development and continuous delivery, organizations' staff also need to be able to provision resources instantly to keep up. You should also be able to deploy new services or applications quickly to make the most of microservices.
Robust monitoring Requirements
Since each service in a microservices application uses its own language, platform, and APIs, multiple teams will be working simultaneously on different services. If any one service or machine fails, it will be difficult, if not impossible, to track down issues in retrospect. Therefore, robust monitoring is essential for effectively monitoring and managing the entire infrastructure.
Complex testing Demands
Each service in a microservices app has its own dependencies. The addition of new features may cause new dependencies and increase complexity. To ensure effectiveness, microservices architectures need to have resiliency testing and fault injection to handle network latency, database errors, caching issues, service unavailability, etc.
Designing with failure in Mind
While creating a microservices architecture, it is important to factor in possible failure issues like slow service, system downtime, and unexpected responses. Despite load balancing measures, the company must also have an alternate plan if a failure arises. In such a situation, the affected service should be able to keep running with degraded functionality rather than crashing the whole system.
New acceptance of DevOps Culture
In traditional companies with monolithic apps, developers were solely focused on features and functionalities, while ops teams worked on production challenges. Microservices apps, however, require businesses to work in cross-functional teams under the common banner of DevOps, where everyone is responsible for both service provisioning and failure.
