Microservices with Spring
- 1. Microservices with Spring Carlos Cavero Barca
- 2. Monolithic is not the evil Esta foto de Autor desconocido está bajo licencia CC BY-NC
- 3. Microservices versus Monolithic Microservices Loosely couple services Distributed architecture and multiple failure points DevOps and Agile cultures easing the use of the hype technologies Easy and quick deployment of new versions More implementation to integrate the services Async and sync communication More configuration and automation Monolithic One big service Multiple functionalities Unique failure point Hard to apply novel technologies due to restrictions Hard and slow deployment of new versions Simple implementation because of simple integration Less configuration (*) https://articles.microservices.com/monolithic-vs-microservices-architecture-5c4848858f59
- 4. Monolithic is not the evil… it is just another alternative architecture to start with Esta foto de Autor desconocido está bajo licencia CC BY-NC
- 5. Microservices patterns and antipatterns Patterns Discovery Load Balancing Circuit Breaker Database per service Observability (health, metrics…) Multiple service per host Externalized configuration API Gateway Access Token Service Decomposition Antipatterns Avoid making microservice the goal Why not start with a monolit? Inefficient processes and practices - waterfall process, manual testing, manual deployment Silo’d organization - e.g. development hands off code to QA for testing. Poor software quality - the application is a big ball of mud, the code is anything but clean, etc (*) https://microservices.io/patterns/microservices.html (*) https://chrisrichardson.net/post/antipatterns/2019/01/14/antipattern-microservices-are-the-goal.html
- 6. Spring Boot Actuator Benefits Provide multiple endpoints with metrics and health information about the Spring service Monitor the status of the application Always add the dependency to your Project (using spring initalizr for instance) Mandatory for service Discovery, traceback, load balancing and circuit breaker Dependency spring-boot-starter- actuator Endpoints Service /health /info /metrics /trace /beans /configprops /env /refresh
- 7. Service Discovery Benefits Solve the ephemeral condition of the microservices Dinamyc configuration of the services Discovering instead of static configuration Discover the host and port by using names instead of Ips or DNS Register when launching the application, the name, host name and available port Consult the /health endpoint of the service (from the dependency actuator) Service Discovery Service1 Service Discovery Service2 register register /health /health
- 8. Service Discovery with Eureka Benefits Client-side Discovery @EnableEurekaServer annotation Cluster configuration recommended En caso de caída se elige uno nuevo y este cambio es transparente para las aplicaciones cliente (si tienen su propio agente Consul cliente configurado correctamente). Eureka, en cambio, si un servidor se cae, son las aplicaciones cliente las que activamente comunican con el siguiente servidor Eureka configurado en ellas. Además, ofrece interfaz DNS para comunicarse, algo que Eureka no por lo que no estamos atados a comunicación REST y además incluye almacenamiento KV, lo que permite centralizar la configuración en el mismo sistema. Netflix Eureka
- 9. Service Discovery with Consul Benefits Client-side Discovery Fault tolerance and load balancing at server side Simple key/value storage for configuration and feature flagging @EnableDiscoveryClient and the dependency spring-cloud-starter-consul-all It can substitute Eureka and Cloud Config Start Consul Agent in local workstation at http://localhost:8500 Download the binary consul agent -server -bootstrap-expect=1 -data- dir=consul-data -ui -bind=<your IP> Consul Service1 Service Discovery Service2 register register /health /health
- 10. API Gateway and intelligent routing with Zuul Benefits Proxy that centralizes all the requests and routes them to the proper microservice Authentication and authorization interceptors Implement Circuit Breaker (Hystrix) Zuul provides Load Balancing in the server side (with Ribbon) and not in the client side like Ribbon Canary testing API Gateway and Routing Zuul Service1 Service Discovery Service2 Client
- 11. Cloud Config Server Benefits Configuration is independent of the artefact Configuration parameters are externalized and it is possible to get the latest version easily Different environments (test, staging and production) can be separated It is language agnostic because it publishes an API REST Refresh automatically the configuration with http://localhost:8090/monitor Encrypt the configuration values at the server side and decrypt at client side with /encrypt and /decrypt endpoints @EnableConfigServer Cloud Config Server Cloud Config Zuul Service1 Service Discovery Service2 Client
- 12. Circuit Breaker with Hystrix Benefits Break the circuit in case of failure or latency (like an electric one) providing valid alternatives instead If the number of errors is above the threshold the circuit is open and no more requests can be done Automatic checking of the /health endpoint until the service is available again Provides resilience and fault tolerance avoiding the propagation of failures, unlimited time-response and isolation of point of access Two possible solutions to return a default value: no availability or failure and timeout @HystrixCommand with a valid fallback Hystrix Service1 Service Discovery Service2 register discover /health /health Hystrix fallback
- 13. Client-side Load Balancing with Ribbon Benefits Load Balancing at client level Multiple instances of the same service Distribution of workloads Get the information from the Discovery service and select the right instance If a instance is not available and Eureka is no updated then some Fallback could be sent. To solve this you can use a proxy (Zuul) Choose and round-robin Ribbon Client Service Discovery Service2 register discover /health Replica1 Replica2 round-robin
- 14. Pub/Sub with RabbitMQ Benefits Message Broker Producers send to the queues Consumers read from the queues Async communication Distributed (micro)services AMQP protocol Message Broker – Spring Cloud Bus Event Producer Consumer1 Consumer2 Consumer3 Client resource.updated resource.created (*) https://reflectoring.io/event-messaging-with-spring-boot-and-rabbitmq/ (*) http://cloud.spring.io/spring-cloud-static/spring-cloud-bus/2.0.0.RELEASE/single/spring-cloud-bus.html#_quick_start (*) http://cloud.spring.io/spring-cloud-static/spring-cloud-config/2.0.1.RELEASE/single/spring-cloud- config.html#_push_notifications_and_spring_cloud_bus
- 15. OpenFeign Benefits Reduce the complexity of binding API HTTP REST calls Takes care of Load Balancing and Discovery if Ribbon and Eureka are included as dependency @FeignClient(name=“spring- service-name")
- 16. Spring Security OAuth Benefits Provides Oauth 2.0 authentication It can also connect with other IdM tools (such as Keycloak)
- 17. Project Lombok Benefits Java library that automatically plugs into your editor and build tools with less programming Fully integrated with Spring Getters, setters or equals methods automatically embedded in the data model With annotations obtain a fully featured builder Automate your logging variables How to make it works in Eclipse IDE Esta foto de Autor desconocido está bajo licencia CC BY-SA When starting a fresh Eclipse installation Lombok needs to be configured: Go where your jar is, run it: java –jar lombok-1.18.8.jar Click on Install/Update Launch Eclipse and update project configuration
- 18. And much more Distributed tracing with Zipkin and Sleuth