Defining cross cutting concerns using the MediatR library 02 Jan 2016 on programming csharp architecture Hello! Aspect-Oriented Programming (AOP) addresses the problem of cross-cutting concerns, which would be any kind of code that is repeated in different methods and can't normally be completely refactored into its module, like with logging, caching, or validation. Such parts include: Logging; Security; Performance; Auditing; All these features are applicable across layers, hence it makes sense to implement them in a common way. Cross-cutting concerns: monitoring and logging This chapter covers Monitoring in a microservice system Exploring structured logging and the Serilog logging library Adding correlation tokens to log messages Logging … - Selection from Microservices in .NET Core: with examples in Nancy [Book] In a layered architecture, there are specific parts that are common to all these different layers. Above, I show a few examples of tracing, exception handling, and transactions , which are all cross-cutting concerns. The PerformanceMonitorInterceptor class is an interceptor that can be associated with any custom method to be executed at the same time. Understanding Cross Cutting Concerns. The cross-cutting concern is a concern which is applicable throughout the application. Tackling cross-cutting concerns with a mediator pipeline 9 September, 2014. In this chapter, you’ll start using the knowledge about OWIN you gained in chapter 8 to create reusable pieces of OWIN middleware that address some important cross--cutting concerns: monitoring and logging. A few months ago I did a freelance gig in which I found myself having trouble to define where exactly to put things like logging, authentication, persistence common logic and so on. Aspect4log solves the cross-cutting concern that every application has, i.e logging. These will allow you to log more with less code and above all your log will have a unified easy to read and analyze format. This affects the entire application. It provides means to enable logging via slf4j by annotating you classes and methods with @Log. In these cases, you can rely on a mediator pipeline (see Mediator pattern) to provide a means for these extra behaviors or cross-cutting concerns. Both are needed across all microservices, and they play an important role in making a microservice system operation-friendly. Cross-Cutting Concerns An important concept in AOP is cross-cutting concerns . Solution Chapter 9. It was a Tuesday. Hope this helps! Spring AOP allows the defining of cross-cutting concerns in applications, meaning code that intercepts the execution of one or more methods, in order to add extra functionality. There are also cross-cutting concerns that are specific to the technologies that the microservices uses. These system services are commonly referred to as cross-cutting concerns because they tend to cut across multiple … A service must implement cross-cutting concerns such as externalized configuration, logging, health checks, metrics, service registration and discovery, circuit breakers. In most of the projects I’ve worked on in the last several years, I’ve put in place a mediator to … You want to be able to add an open number of cross-cutting concerns like logging, validations, audit, and security. For example, logging, security and data transfer are the concerns needed in almost every module of an application, thus they are the cross-cutting concerns. Cross Cutting Concerns are global concerns that span across methods, classes, applications—and can be concerns widely affecting a whole company or industry. Think of patient records or a financial history, and things always needed in those industries and how it affects each method of code! Even in an individual layer, logging could be used across all classes/services, cutting through and … Originally posted on the Skills Matter website. Logging is the most common example of a cross-cutting concern, because you might use logging in the UI layer, in the business logic, in the persistence layer, etc.