問題描述:
UserClient
@FeignClient(value = "userservice", fallback = UserClientFallback.class)
public interface UserClient {
@GetMapping("user/{id}")
User queryById(@PathVariable("id") Long id);
}
UserClientFallback
@Component
public class UserClientFallback implements UserClient {
@Override
public User queryById(Long id) {
User user = new User();
user.setName("未知用戶");
return user;
}
}
controller
@RestController
@RequestMapping("consumer")
@DefaultProperties(defaultFallback = "queryUserByIdFallback")
public class ConsumerController {
@Autowired
private UserClient userClient;
@GetMapping("{id}")
public User queryUserById(@PathVariable("id") Long id) {
return userClient.queryById(id);
}
public User queryUserByIdFallback() {
User user = new User();
user.setName("用戶信息查詢出現異常!");
return user;
}
服務提供者是可用的,消費者客戶端一直走fallback方法
問題原因:
如果執行的方法導致Hystrix超時也會去執行fallback方法,這樣也就不會去執行業務代碼。
Hystrix有個默認的超時時間,默認是1000ms(1秒),源碼如下:
private static final Integer default_executionTimeoutInMilliseconds = 1000; // default => executionTimeoutInMilliseconds: 1000 = 1 second
問題解決:
我們設置Hystrix的超時時間更久,要超過Ribbon等的超時時間(此配置在IDEA裏是沒有信息提示):
hystrix:
command:
default:
execution:
isolation:
thread:
timeoutInMilliseconds: 6000 # 設置hystrix的超時時間爲6000ms
本人yml配置:
server:
port: 8080
spring:
application:
name: userconsumer
eureka:
client:
service-url:
defaultZone: http://127.0.0.1:8088/eureka
instance:
prefer-ip-address: true # 當其它服務獲取地址時提供ip而不是hostname
ip-address: 127.0.0.1 # 指定自己的ip信息,不指定的話會自己尋找
ribbon:
NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule # 默認爲;輪詢,這裏改爲隨機
ConnectTimeout: 5000 # 連接超時時間(ms)
ReadTimeout: 5000 # 通信超時時間(ms)
feign:
hystrix:
enabled: true # 開啓Feign的熔斷功能
hystrix:
command:
default:
execution:
isolation:
thread:
timeoutInMilliseconds: 6000 # 設置hystrix的超時時間爲6000ms