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Custom and business applications running on enterprise mobile devices should be able to maximize efficiency and productivity on the back end while maintaining quality UX.
To achieve these goals, IT teams can turn to event-driven architectures (EDAs) for these applications that decouple event production from event consumption to increase the app's versatility, adaptability and scalability.
Event-driven architecture benefits an organization's mobile users due to improvements it can provide for workflow efficiency, communication speed and other factors, but mobile admins should have a basic understanding of how EDA works and what its components are.
Understanding the basics of event-driven applications and architecture
Before learning what event-driven architecture is, IT professionals should make sure they understand what event means in this context.
Components of event-driven architecture
At the heart of EDA is the Event, which is a formatted piece of data that communicates a change of state. This change of state results from an occurrence or specific action, often related to a user's actions.
For example, when an employee uses a mobile app to update a schedule or inventory item, the app generates an event that one or more services then listen to or consume. Those services can then carry out processes in response to that specific event. The event producer has no knowledge of the event consumers, and the consumers have no knowledge of the event producer or any other consumers. If multiple workers use the app to carry out different tasks, a steady stream of events will flow from the different mobile devices into a common channel.
At its most basic, the EDA consists of three types of components: event producers, event channels and event consumers. They may be referred to by other names, but most EDA systems follow the same basic outline. The producers and consumers operate without knowledge of or dependencies on each other, making it possible to develop, deploy, scale and update the components independently. The events themselves tie the decoupled pieces together.
A producer can be any application, service or device that generates events for publishing to the event channel. Producers can be mobile applications, IoT devices, server services or any other systems capable of generating events. The producer is indifferent to the services and systems that consume the event and is concerned only with passing on formatted events to the event channel.
The event channel provides a communication hub for transferring events from the producers to the consumers. The event channel could take the form of a router, pipeline, broker, message queue, service bus, stream processor or whatever other form does the job. The idea is to provide an intermediary layer between the producers and consumers for filtering events and transferring them to the consumers.
The event channel can support multiple consumers, each serving a specific purpose. The consumers listen for the events and carry out any actions warranted by the events without communicating back to the producer. Multiple consumers can process the same events, and the consumers themselves can generate events in response to incoming events, turning them into producers as well as consumers.
How event-driven architecture benefits enterprise systems and developers
A mobile app built with EDA might also be part of an enterprise-wide workflow that incorporates other types of systems and applications, all of which are generating their own events. The systems and apps can generate the events automatically or through user actions. For example, when a mobile user attempts to access a secure company database, the mobile app could trigger events that authenticate the device, perform analysis on whether the request is suspicious and deliver the data.
These events also stream into a common channel for quick processing. An EDA system makes it possible to handle all these events within a single event-driven infrastructure, and any mobile apps built with EDA can fit into this channel.
EDA is not a development platform or a programming language; instead, it is a programming framework that provides a flexible architecture for producing, routing, consuming and reacting to events. Event processing occurs separately from the rest of the application, carried out by one or more decoupled services. Developers can build event-driven applications using whatever programming language is appropriate for their platform and define the events to meet their specific requirements.
Event-driven systems are sometimes categorized as either reactive or stream processing. The difference between the two lies in how the events are integrated into the larger EDA structure. Reactive programming adheres to a publisher or subscriber model, whereas the event processing approach handles events as a stream. Event streaming is more relevant to enterprise IT professionals, especially with the proliferation of cloud services.
EDA offers several other benefits to developers. For example, developers can easily add or update producers and consumers without having to reconfigure the system or take it offline. The EDA is also highly scalable and fault-tolerant, while providing the versatility to incorporate multiple enterprise systems, including mobile apps. In addition, the EDA supports parallel development and live testing efforts and enables development teams to control how events are defined.
How is EDA different from request-driven architecture?
EDA breaks away from traditional software architectures that favor a request-driven model, in which events are tied to specific outcomes. In this scenario, the application code makes requests to other modules and waits for responses before continuing. Although the request-driven architecture provides a more structured and consistent approach than the EDA, it's not as flexible or scalable, making it less suited to many of today's complex enterprise workloads.
Event-driven architecture benefits for mobile users and IT pros
Mobile users also benefit from apps and systems built with EDA because their applications can be integrated into the greater enterprise infrastructure, leading to more responsive mobile apps. Users get the full power of the same back-end systems that drive other applications and services, which makes mobile workflows more cohesive and integrated.
With EDA, admins can incorporate new components and workflow patterns to mobile devices quicker, resulting in greater user productivity and a better mobile UX. In addition, multiple business teams can respond to the same events in real time at any location, increasing efficiency and responsiveness across the entire organization. An event-driven structure also provides opportunities for IT to tap into event streams and derive insights into operational patterns and trends, which can reveal any inefficiencies that are hindering productivity.
IT departments are turning to event-driven platforms and systems to support use cases with complex and varied workflows. Take, for example, an e-commerce website that has an app for customers and employees to submit and carry out transactions. When customers place orders, submit questions, update their profiles or search available products on a mobile app, it generates the appropriate events and passes them on to the event channel, which then transfers them to multiple consumer services. In response to these events, the consumer systems might launch fulfillment processes, update customer records, adjust inventories, notify customers services or carry out a variety of other tasks.
At the same time, employees can use mobile devices to update orders, verify stock, confirm shipments, respond to customer requests or perform other actions. Any of these individual actions might generate their own events, which are looped into the event channel just like the original events. With an event-driven approach to an organization's systems, all activities are coordinated and tracked within a common, enterprise-wide framework.
Fitting event-driven architecture into an organization
Despite all of event-driven architecture's benefits, the architecture is not suited to every workload or organization. For example, the EDA is usually not a good fit for distributed transactional processes that require data to always be in a consistent state. The asynchronous nature of EDA systems can make it difficult to track and troubleshoot the event stream and guarantee event delivery -- at least to the degree needed for certain critical operations.
Under the right circumstances, however, the EDA can benefit a variety of workflows, especially when used in conjunction with modern technologies such as microservices, serverless computing or functions-as-a-service. Applications and systems with EDA require specific types of support, monitoring and management tools. For example, some organizations use Apache Kafka as an alternative to traditional messaging systems. Event-driven architecture benefits from Apache Kafka because it provides a distributed data streaming platform that can publish, consume, store and process event streams in real time.