Employing a microservices API gateway can significantly streamline development efforts, enhance application efficiency, and reduce errors simultaneously. One of the key benefits of utilizing microservices is the ability to avoid dealing with a monolithic codebase. Microservices offer modularity and flexibility, allowing precise selection of code components to interact with and their sources. This modular approach facilitates mixing and matching of code components as needed. However, the decentralized nature of microservices can pose challenges, as code components may originate from diverse sources, each with its own set of conventions and rules.
Attempting to manage the multitude of microservices and determining their optimal usage can be a daunting task for even the most meticulous developers, leading to frustration and concern. Simplifying the management and accessibility of microservices is one of the driving factors behind the adoption of an API gateway.
Integration of an API gateway transforms your array of microservices into a tailored API solution, finely crafted to cater to the unique requirements of your application. While presenting itself as a cohesive API on the surface, beneath the surface it orchestrates individual microservices to execute tasks, offering the perfect blend of versatility and functionality. This guide equips you with the essential insights into leveraging an API gateway, empowering you to gain a significant edge over competitors who may still be grappling with the complexities of managing disparate microservices. Before delving into the intricacies of setting up a microservices architecture, delve into this article for a foundational understanding.
In numerous aspects, a microservices API gateway operates much like any conventional API gateway. It’s crucial to differentiate between a microservices API gateway and API management (for further insight, refer to the article, ‘How Amazon API Gateway Revolutionizes Your API Management Approach’ for clarification). Essentially, a microservices API gateway serves as a frontend interface for accessing the underlying microservices—it doesn’t facilitate the publication, promotion, or administration of services to a significant extent.
Yet, a microservices API gateway offers more than merely establishing a solitary interface for a singular application. A solitary microservices API gateway possesses the capability to generate multiple APIs—tailored to each platform requirement, as depicted in Figure 1. For instance, accommodating smartphone native applications, browsers, and server-side applications might necessitate distinct sets of microservice functionalities (and possibly diverse protocols). Through an API gateway, a unique API can be crafted for each client, presenting only the relevant features to the client interface. This approach replaces a cumbersome assortment of microservices with a streamlined API customized for each platform, facilitating rapid and effortless application development.
Arranging microservices in specific configurations is only a partial solution. Each microservice may also possess unique requirements, with protocol compatibility being the most prevalent. Directly interfacing with each microservice using its individual protocol setup within a client application is arduous. The microservices API gateway facilitates protocol translation, ensuring that each microservice receives requests in its preferred protocol, while clients interact with a unified protocol they handle most effectively. Leveraging protocol translation allows developers to concentrate on programming tasks rather than the intricacies of microservice access—streamlining development efforts and mitigating potential coding errors simultaneously.
Enabling clients and services to utilize protocols tailored to their specific requirements also enhances speed. The microservices API gateway seamlessly conducts all necessary protocol translations, ensuring uniform communication despite diverse protocols. This yields an optimized communication channel, facilitating accelerated data transfer between endpoints.
The microservices API gateway streamlines the process for clients to retrieve data by enabling them to make a single request. When interacting directly with microservices, a client might have to make multiple calls to different services to gather sufficient data for just one screen. Each of these calls consumes network bandwidth and necessitates extra client-side coding. By consolidating these calls into a single request, efficiency is significantly enhanced.
During the development phase, while one team focuses on crafting microservices, another concentrates on creating applications that utilize these microservices. To facilitate concurrent progress for both teams, a common strategy involves leveraging mocking or API-centric service virtualization. In this approach, a call to a microservice elicits a static or dynamic response, often facilitated by tools like ServiceV in Ready API. This simulated response acts as a placeholder for the microservice until it becomes operational and can furnish real-time data. By utilizing a microservices API gateway, configuration tasks associated with mocking can be seamlessly executed, concealing the fact that the data is simulated. Consequently, the application behaves identically to how it will when the microservice code is finalized. For developers, this means that activities such as debugging closely mirror real-world scenarios, eliminating the need for later configuration adjustments once the microservice is operational. From the application’s perspective, the microservice consistently operates at full functionality, even during the mock phase of the development cycle.
At first glance, employing a microservices API gateway might appear to offer an ideal remedy to managing numerous microservices. Nonetheless, like any solution, it comes with its own set of drawbacks. One of the most apparent is the necessity to configure yet another software component on the server. While configuring the gateway may consume less time compared to developers individually coding for each microservice, this efficiency is contingent upon seamless functionality without any hitches.
Furthermore, employing a microservices API gateway introduces an extra potential point of failure. Situations may arise where a configuration mistake triggers a perplexing application bug. Additionally, the server hosting the microservices API gateway might experience crashes, or the application could encounter difficulties in establishing communication with the server for various reasons. Indeed, the microservices API gateway could fail in numerous ways, exacerbating reliability issues rather than alleviating them.
Employing a microservices API gateway enhances efficiency for all parties involved and expedites data transfers. However, to harness these advantages, it’s imperative that the server employed supports non-blocking asynchronous I/O. Failure to do so compromises both speed and scalability, resulting in the microservices API gateway becoming a bottleneck.
Because of the way microservices API gateways work, you need to write your application in a declarative style using a reactive approach. Products such as Promise make this approach possible for JavaScript developers and there are other products for other languages. Using a declarative style makes it possible for the microservices API gateway to decide how to fulfill requests and reduces the client workload. Consequently, when a request requires several concurrent calls, the microservices API gateway can perform them all at once. Likewise, when the microservices API gateway must first authenticate the user before making a microservices request, it can do so without querying the client.
In many instances, the locations of microservices are dynamically allocated, necessitating that any microservices API gateway employed offers mechanisms for on-demand discovery of microservices. As microservices auto-scale or undergo upgrades by developers, the microservices API gateway must seamlessly adapt to ensure uninterrupted application functionality. Typically, the microservices API gateway identifies microservices through a service registry.
Another aspect to consider is the necessity for the microservices API gateway to effectively manage partial failures. It’s crucial that the failure of a single unresponsive microservice doesn’t lead to the failure of the entire request. Various strategies can be employed by the microservices API gateway to handle such partial failures.