Microservice Architecture Glossary §
A work-in-progress definition of terms that are not expressed as patterns.
API §
A service’s reason for existing. It consists of:
- Zero or more operations
- Zero or more published domain events
Command §
A command is an operation that mutates data.
Component §
A component is a software unit that is executable or deployable. For example, a Java WAR file or executable JAR file; or an operating system executable.
DORA metrics §
Developed by the authors of Accelerate, the DORA metrics measure the performance of a software development teams:
- Deployment frequency - the frequency with which software changes are deployed to production.
- Lead time for changes - the time it takes to go from commit to deploy.
- Change failure rate - the percentage of production deployments that result in a failure or require remediation.
- Time to restore service - the time it takes to restore service after a production incident or outage.
The DORA DevOps Quick Check is a simple five question assessment of how well you are delivering software.
Modular monolith §
A variant of the monolithic architecture that is organized around subdomains (e.g. business capabilities) rather than technical layers (e.g. presentation, business logic, persistence).
Monolithic architecture §
An architectural style that structures the application as a single executable/deployable component. See the Monolithic architecture pattern for more details.
Microservice architecture §
An architectural style that structures at application as set of loosely coupled, independently deployable components (a.k.a. services). See the Microservice architecture pattern for more details.
Operation §
An operation is an invocable behavior of a service. There are two types of operations: commands and queries. An operation can be invoked by a service client either synchronously or asynchronously. It might also be invoked by the passing of time, e.g. to implement a batch job.
Pattern §
A pattern is a “reusable solution to a problem that occurs in particular context”. Read more
Query §
A query is an operation that retrieves data.
Service §
Each service is an element of the Microservice Architecture that is:
- Loosely coupled with other services
- Independently deployable - it an independently deployable/executable component, such as a WAR file, executable JAR, EAR file, OSGI Bundle, or operating System executable
- Owned by a small, cross-functional team
A service has an API.
System operation §
A system operation is an invocable behavior of the application. There are two types of operations: commands and queries. An operation is invoked by an application client - human via UI, or an external application - either synchronously or asynchronously. It might also be invoked by the passing of time, e.g. a batch job that is executed periodically.
In a microservice architecture, a system operation is either local or distributed. A local operation is implemented by a single service. A distributed operation is implemented by multiple collaborating services.
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