Microservices architectures (MSA) break down domain-level problems into independent modular capacities so they become easier to manage and deploy, which is great for many situations. When that system is organized around events — an event-driven microservices architecture (EDM) — you are streamlining microservices into event-defined clusters, which then function faster and with improved productivity than they did in a monolithic formation. This event-driven microservices architecture offers benefits that you won’t find in other MSA patterns.
There are challenges, too, however. Scaling an MSA, for example, is more complex than scaling a monolith because the microservice design has so many more moving parts. While you may want to simply duplicate your entire function in a new setting, you may also only need to scale elements of it. Both cases require a careful analysis of how the scaled elements will impact the existing system so you can design around their particular concerns.
Why Event-Driven Integration Architecture (EDA)?
- Multiple subsystems must process the same events.
- Real-time processing is required with minimum time lag.
- Complex event processing is needed, such as those projects that involve aggregation over time-windows or pattern matching.
- There is a need for swift processing of high volumes and velocities of incoming data.
Further, its high level of optimization and ease of use let users “tune” how they want their events emitted, collected and consumed, and its immediacy gives them control over what’s happening in their system.
Its scalability is also an added boon, even with the challenges that it poses, because the scaling solution must be as unique as the EDA itself. For example, a retailer may want to scale its entire operation in another location, which would suggest duplicating the entire EDA. Conversely, a seasonal retailer may need only to scale their sales programming during peak seasons. A scaled EDA in both situations requires a careful analysis of load balances, system resources and intended outcomes to achieve its intended goal.
A Cohesive Event-Driven Microservices (EDM) Architecture
The unique organization of events and microservices generates a host of benefits that are unattainable with point-to-point processing, including the following:
- Events Do Most Of The Heavy Lifting: Events-based integration eliminates the logic and log-scraping coding that is traditionally used for wiring portability and scalability into the architecture. Developers can focus on tuning the business functions of their apps, not their internal programming details.
- Automatic Foreign Key Constraint Updates Between Services: A foreign key process coordinates user-service and corresponding search-service activities. When optimized, the foreign key ensures that any modifications, additions or deletions of the user-service data automatically trigger the respective resulting events, concurrently update the search-service and update the function with the dynamic data.
- Distributed Transactions Make Disaster Recovery Easy: Any concerns that arise during the execution of multiple simultaneous transactions will be identified by the particular event for the defaulting service, and a rollback to a pre-concerned state will be carried out automatically.
- Less Service Coupling: Information exchanged between two services does not require updates between the two. The inner outreach and response complexities of the other service are handled by the events triggered for those services — not within each service individually.
- Improved Scalability: EDM eliminates delays caused by the traditional request-response mechanism because the capacities of individual services grow dynamically on an as-needed basis — not in relation to the functioning of the others. The system’s scalability factor grows as the capacities of its internal services grow.
- Services Are Smaller And Simpler: Each service performs only its unique function and is not required to manage systems-sized challenges, such as complex error-handling functions for downstream service or network failures.
- Enables fine-grained scaling: Each service can be independently scaled up or down based on demand, which conserves computing resources.
- Events Optimize the User Experience: The user experience is better because events are arriving in real-time, eliminating the waste of bandwidth and computing resources on time-consuming requests.
- EDM also coordinates both more granular and comprehensive computing processes:
- It respects legacy systems and configurations. A business adapter connects the new to the old and connectors link the new system to existing cloud services (Twitters, PayPal, etc.). It also wraps legacy services with new interfaces and its multiple extension points integrate well with custom or proprietary systems.
- Configuration drives function, not code. Message flow configurations can manipulate message content, direction, destination and protocols. It can bridge different protocols, too (e.g., JMS to HTTP), retaining the value of existing connections.
- It supports enterprise integration patterns (EIP) without eroding your quality of service, encompassing security, throttling, or caching processes.
Optimizing Enterprise Integration
Ultimately, an EDM enhances enterprise integration, which has been the goal all along of evolving enterprise-level computing systems. Reducing system functionality to its integral events and eliminating the web-like maze of connections between a myriad of corporate applications, EDM also eliminates the resulting confusion. As a middleware solution, EDM can integrate the entire organizational infrastructure into a more functional system.
The emerging EDM brings forward the benefits of each style of legacy system, while leaving their challenges behind. It provides users all the services they’ve come to expect from today’s modern computing sector:
4. Independence and autonomy
5. Decentralized governance
6. Failure isolation
8. Continuous delivery through DevOps
The Importance Of An EDM
The benefits of an EDA, when coupled with microservices, are many, including lower up-front costs, reducing time-to-market and a reduction of the need for invasive refactoring or disruptions of existing application development efforts. Designing one to match and optimize your enterprise will require significant preparation and analysis of how your organization presently functions, which may not be within the scope of possibility for some businesses. It’s important to decide whether this added effort is worth the benefits that come with an EDM — before you jump into the thick of it.
POST WRITTEN BY
Director, Digital Modernization | Principal Architect | Technology Evangelist for Sage IT Inc.