Zuul的負載均衡

1.默認配置

Zull默認結合Ribbon負載均衡的實現，Ribbon默認的負載均衡算法是ZoneAvoidanceRule

2.修改算法配置

配置方式和Ribbon的消費者中配置一樣，也可以自定義隨機算法

@Configuration
public class RibbonClientConfig {
    @Bean
    public IRule getRule() {
        return new RandomRule();
    }
}

熔斷配置

增加熔斷配置，當服務不可用的時候，自動會觸發熔斷

@Component
public class MyZuulFallBack implements FallbackProvider {
    private final Logger logger = LoggerFactory.getLogger(MyZuulFallBack.class);
    /**
     * getRoute方法的返回值就是要監聽的掛掉的微服務名字
     * api服務id，如果需要所有調用都支持回退，則return "*"或return null
     *
     * @return
     */
    public String getRoute() {
        return "*";
    }
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        logger.info("--> route:{}進行熔斷降級", route);
        return new ClientHttpResponse() {
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.OK;
            }
            public int getRawStatusCode() throws IOException {
                return this.getStatusCode().value();
            }
            public String getStatusText() throws IOException {
                return this.getStatusCode().getReasonPhrase();
            }
            public void close() {
            }
            public InputStream getBody() throws IOException {
                return new ByteArrayInputStream("服務不可用".getBytes());
            }
            public HttpHeaders getHeaders() {
                HttpHeaders headers = new HttpHeaders();
                headers.setContentType(MediaType.APPLICATION_JSON);
                return headers;
            }
        };
    }
}