This is a continuation of a series of articles on operational engineering aspects of Azure public cloud computing the included the most recent discussion on Azure Maps which is a full-fledged general availability service that provides similar Service Level Agreements as expected from others in the category. In this article, we explore Azure Logic applications.

Each logic app is a workflow that implements some process. This might be a system-to-system process, such as connecting two or more applications. Alternatively, it might be a user-to-system process, one that connects people with software and potentially has long delays. Logic Apps is designed to support either of these scenarios.

Azure Logic Applications is a member of Azure Integration Services. It simplifies the way legacy, modern and niche systems are connected across cloud, on-premises and hybrid environments. The integrated solutions are very valuable for B2B scenarios. Integration services distinguish themselves with four common components in their design – namely, APIs, Events, Messaging, and Orchestration. APIs are a prerequisite for interactions between services. They facilitate functional programmatic access as well as automation. For example, a workflow orchestration might implement a complete business process by invoking different APIs in different applications, each of which carries out some part of that process. Integrating applications commonly requires implementing all or part of a business process. It can involve connecting software-as-a-service implementation such as Salesforce CRM, update on-premises data stored in SQL Server and Oracle database and invoke operations in an external application. These translate to specific business purposes and custom logic for orchestration. Many backend operations are asynchronous by nature requiring background operations. Even APIs are written with asynchronous processing but long running APIs are not easily tolerated. Some form of background processing is required. Situations like this call for a message queue. Events facilitate the notion of publisher-subscriber so that the polling on messages from a queue can be avoided. For example, Event Grid supports subscribers to avoid polling. Rather than requiring a receiver to poll for new messages, the receiver instead registers an event handler for the event source it’s interested in. Event Grid then invokes that event handler when the specified event occurs. Azure Logic applications are workflows. A workflow can easily span all four of these components for its execution.

Azure Logic Applications can be multi-tenant. It is easier to write the application as multi-tenant when we create a workflow from the template's gallery. These range from simple connectivity for Software-as-a-service applications to advanced B2B solutions. Multi-tenancy means there is a shared, common infrastructure across numerous customers simultaneously, leading to economies of scale