Sentinel降级操作

1.通过对feign调用的降级 如果访问失败，则返回另外的信息

正常的feign调用

@FeignClient(value = "gulimall-seckill",fallback = SeckillFeignServiceFallback.class) public interface SeckillFeignService { /** * 写给商品服务的接口，查询秒杀服务信息 * @param skuId * @return */ @GetMapping("/currentSeckillSkus/sku/seckill/{skuId}") R getSkuSeckillInfo(@PathVariable("skuId") Long skuId); }

兜底方法返回另外的信息

/** * 如果feign调用失败返回的信息 */ @Component public class SeckillFeignServiceFallback implements SeckillFeignService { @Override public R getSkuSeckillInfo(Long skuId) { return R.error(500,方法调用失败); } } 2.对代码进行访问控制，在可视化工具中对seckillSkus进行数据设置 @Override public List<SecKillSkuRedisTo> getCurrentSeckillSkus() { //1.确定当前时间属于哪个秒杀场次 long time = new Date().getTime(); try(Entry seckillSkus = SphU.entry("seckillSkus")){ //正常的业务代码----- } //然后在可视化工具中对这个代码进行限流控制设置 }catch (BlockException e){ System.out.println("资源被限流"); } return null; } 3.统一config配置返回降级信息 ** * 自定义流量控制请求失败后返回信息 */ @Configuration public class SeckillSentinelConfig { public SeckillSentinelConfig(){ WebCallbackManager.setUrlBlockHandler(new UrlBlockHandler() { @Override public void blocked(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlockException e) throws IOException { R error = R.error(BizCodeEnum.TO_MANY_REQUEST.getCode(), BizCodeEnum.TO_MANY_REQUEST.getMsg()); httpServletResponse.setCharacterEncoding("UTF-8"); httpServletResponse.setContentType("application/json"); httpServletResponse.getWriter().write(JSON.toJSONString(error)); } }); } } 4.使用注解结合可视化操作进行控制 public List<SecKillSkuRedisTo> blockHandler(BlockException e){ log.error("getCurrentSeckillSkus被限流了"); return null; } /** * 返回当前时间段可以参加秒杀的商品信息 * Entry seckillSkus = SphU.entry("seckillSkus"对代码进行降级 * @return */ @SentinelResource(value = "getCurrentSeckillSkus",blockHandler = "blockHandler") @Override public List<SecKillSkuRedisTo> getCurrentSeckillSkus() { return null; }

 @SentinelResource(value = "getCurrentSeckillSkus",blockHandler = "blockHandler")

value的名称是可视化页面的限流处理名称

blockHandler的内容是限流降级后的操作方法

两个方法返回类型要一致

5.整合sentine和gateway

引入依赖

<!-- sentinel和gateway整合--> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-alibaba-sentinel-gateway</artifactId> <version>2.1.0.RELEASE</version> </dependency>

版本需要和common中的阿里依赖一致

<dependencyManagement> <dependencies> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-alibaba-dependencies</artifactId> <version>2.1.0.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement>

config文件

@Configuration public class SentinelGatewayConfig { public SentinelGatewayConfig(){ GatewayCallbackManager.setBlockHandler(new BlockRequestHandler() { @Override public Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) { R error = R.error(BizCodeEnum.TO_MANY_REQUEST.getCode(), BizCodeEnum.TO_MANY_REQUEST.getMsg()); String jsonString = JSON.toJSONString(error); Mono<ServerResponse> body = ServerResponse.ok().body(Mono.just(jsonString), String.class); return body; } }); } }

也可以配置相关的信息

配置网关返回的状态码 spring.cloud.sentinel.scg.fallback.response-status=400