Display → Product 연동 구간에 Circuit Breaker를 적용! |
compile('org.springframework.cloud:spring-cloud-starter-netflix-hystrix') |
@EnableCircuitBreaker |
@HystrixCommand |
git checkout tags/step-2-hystrix-fallback -b step-2-hystrix-fallback |
@RestController
@RequestMapping("/products")
public class ProductController {
@GetMapping(path = "{productId}")
public String getProductInfo(@PathVariable String productId) {
// return "[product id = " + productId + " at " + System.currentTimeMillis() + "]";
throw new RuntimeException("I/O Exception");
}
} |
@Service
public class ProductRemoteServiceImpl implements ProductRemoteService {
private static final String url = "http://localhost:8082/products/";
private final RestTemplate restTemplate;
public ProductRemoteServiceImpl(RestTemplate restTemplate) {
this.restTemplate = restTemplate;
}
@Override
@HystrixCommand(fallbackMethod = "getProductInfoFallback")
public String getProductInfo(String productId) {
return this.restTemplate.getForObject(url + productId, String.class);
}
public String getProductInfoFallback(String productId) {
return "[ this product is sold out ]";
}
} |
|
git checkout tags/step-2-hystrix-fallback2 -b step-2-hystrix-fallback2 |
@Service
public class ProductRemoteServiceImpl implements ProductRemoteService {
private static final String url = "http://localhost:8082/products/";
private final RestTemplate restTemplate;
public ProductRemoteServiceImpl(RestTemplate restTemplate) {
this.restTemplate = restTemplate;
}
@Override
@HystrixCommand(fallbackMethod = "getProductInfoFallback")
public String getProductInfo(String productId) {
return this.restTemplate.getForObject(url + productId, String.class);
}
public String getProductInfoFallback(String productId, Throwable t) {
System.out.println("t = " + t);
return "[ this product is sold out ]";
}
} |
http://localhost:8081/displays/11111
2020-02-25 11:32:22.068 INFO 69092 --- [io-8081-exec-10] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring FrameworkServlet 'dispatcherServlet' 2020-02-25 11:32:22.068 INFO 69092 --- [io-8081-exec-10] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started 2020-02-25 11:32:22.174 INFO 69092 --- [io-8081-exec-10] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 106 ms t = org.springframework.web.client.HttpServerErrorException: 500 null |
|
@RestController
@RequestMapping("/products")
public class ProductController {
@GetMapping(path = "{productId}")
public String getProductInfo(@PathVariable String productId) {
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
return "[product id = " + productId + " at " + System.currentTimeMillis() + "]";
//throw new RuntimeException("I/O Exception");
}
} |
hystrix:
command:
default: # command key. use 'default' for global setting.
execution:
isolation:
thread:
timeoutInMilliseconds: 1000 |
|
|
hystrix:
command:
default: # command key. use 'default' for global setting.
execution:
isolation:
thread:
timeoutInMilliseconds: 3000
circuitBreaker:
requestVolumeThreshold: 1 # Minimum number of request to calculate circuit breaker's health. default 20
errorThresholdPercentage: 50 # Error percentage to open circuit. default 50 |
@RestController
@RequestMapping("/products")
public class ProductController {
@GetMapping(path = "{productId}")
public String getProductInfo(@PathVariable String productId) {
// try {
// Thread.sleep(2000);
// } catch (InterruptedException e) {
// e.printStackTrace();
// }
//
// return "[product id = " + productId + " at " + System.currentTimeMillis() + "]";
throw new RuntimeException("I/O Exception");
}
} |
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