Spring Cloud Gateway is a component in the Spring Cloud ecosystem and is used to build gateway services in a Spring Boot-based microservice architecture. Its main purpose is to provide a flexible way to route, filter and transform HTTP requests, allowing you to build powerful, high-performance microservice applications.
The following are some of the core principles and features of Spring Cloud Gateway:
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Routing : Spring Cloud Gateway allows you to define a series of routing rules to map incoming HTTP requests to different target services. These routing rules are usually defined using configuration files or Java code, allowing you to specify conditions such as the URL path, HTTP method, and request header of the request, and route them to the backend microservice.
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Filters : Gateway has a configurable chain of filters for performing various operations when requests enter and responses leave the gateway, such as authentication, logging, request and response modification, etc. You can define custom filters to meet specific needs.
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Circuit Breaker : Gateway supports circuit breaker mode to prevent the propagation of faults. When the backend service is unavailable or overloaded, it can prevent unstable requests from continuing to access, thus improving the stability of the system.
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Load Balancing : Gateway has a built-in load balancing function that can evenly distribute requests to multiple instances or replicas of services. You can choose different load balancing algorithms to suit your needs.
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Route Predicates : Gateway uses route predicates to match incoming requests. Predicates can be matched based on the request path, host, request header and other conditions, and the request can be routed to the matching target service.
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Filter Factories : Gateway provides a series of built-in filter factories for performing common operations, such as authentication, authorization, request and response modification, etc. You can also create custom filter factories to meet specific needs.
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WebFlux : Spring Cloud Gateway is built on top of Spring WebFlux, which enables it to handle a large number of concurrent requests, as well as support a non-blocking and reactive programming model.
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Dynamic routing : Gateway supports dynamic routing configuration, which means that you can dynamically add, modify or delete routing rules at runtime without restarting the gateway service.
Overall, Spring Cloud Gateway provides a flexible, scalable way to manage request routing, filtering, and transformation in a microservices architecture. It is one of the powerful tools for building cloud-native, microservices applications with high performance and configurability to meet the needs of different projects.