I've checked the questions on the site about Resilience4J, but have not had any luck with their answers. I'm trying to implement @CircuitBreaker annotation from Resilience4J in my Spring Boot 2.x project. The circuit breaker is implemented around a pretty straightforward function. However, when I supply a bad URL, the circuit is not opening, no matter how many times I send the request. I've gone so far as to extract everything into a standalone application and run it 100 times and observe it just endlessly failing. Any idea what I'm doing wrong?
@CircuitBreaker(name = "backendA")
@Component
public class ResilientClient {
private HttpClient httpClient;
private static final Logger log = LoggerFactory.getLogger(ResilientClient.class);
public ResilientClient() {
httpClient = HttpClient.newBuilder().build();
}
@Bulkhead(name = "backendA")
public String processPostRequest(String body, String[] headers, String url) {
HttpResponse<String> response = null;
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create(url))
.POST(HttpRequest.BodyPublishers.ofString(body))
.headers(headers)
.build();
try {
response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
} catch (IOException e) {
throw new HttpServerErrorException(HttpStatus.INTERNAL_SERVER_ERROR, "This is a remote exception");
} catch (InterruptedException e) {
e.printStackTrace();
log.error("Interrupted Exception: " + e.getLocalizedMessage(), e);
}
return response != null ? response.body() : null;
};
// None of these functions ever get invoked
private String fallback(Throwable e){
log.info("generic throwable caught");
return "generic result";
}
private String fallback(String param1, String[] headers, String url, Throwable e) {
log.info("Fallback method invoked for Throwable: " + param1);
return null;
}
private String fallback(String param1, String[] headers, String url, ConnectException e) {
log.info("Fallback method invoked for ConnectException: " + param1);
return null;
}
}
The config file is taken directly from the Github example
resilience4j.circuitbreaker:
configs:
default:
registerHealthIndicator: false
slidingWindowSize: 10
minimumNumberOfCalls: 5
permittedNumberOfCallsInHalfOpenState: 3
automaticTransitionFromOpenToHalfOpenEnabled: true
waitDurationInOpenState: 2s
failureRateThreshold: 50
eventConsumerBufferSize: 10
recordExceptions:
- org.springframework.web.client.HttpServerErrorException
- java.io.IOException
ignoreExceptions:
- io.github.robwin.exception.BusinessException
shared:
registerHealthIndicator: true
slidingWindowSize: 100
permittedNumberOfCallsInHalfOpenState: 30
waitDurationInOpenState: 1s
failureRateThreshold: 50
eventConsumerBufferSize: 10
ignoreExceptions:
- io.github.robwin.exception.BusinessException
instances:
backendA:
baseConfig: default
backendB:
registerHealthIndicator: true
slidingWindowSize: 10
minimumNumberOfCalls: 10
permittedNumberOfCallsInHalfOpenState: 3
waitDurationInOpenState: 1s
failureRateThreshold: 50
eventConsumerBufferSize: 10
recordFailurePredicate: io.github.robwin.exception.RecordFailurePredicate
resilience4j.retry:
configs:
default:
maxRetryAttempts: 2
waitDuration: 100
retryExceptions:
- org.springframework.web.client.HttpServerErrorException
- java.io.IOException
ignoreExceptions:
- io.github.robwin.exception.BusinessException
instances:
backendA:
maxRetryAttempts: 3
backendB:
maxRetryAttempts: 3
resilience4j.bulkhead:
configs:
default:
maxConcurrentCalls: 100
instances:
backendA:
maxConcurrentCalls: 10
backendB:
maxWaitDuration: 10ms
maxConcurrentCalls: 20
resilience4j.thread-pool-bulkhead:
configs:
default:
maxThreadPoolSize: 4
coreThreadPoolSize: 2
queueCapacity: 2
instances:
backendA:
baseConfig: default
backendB:
maxThreadPoolSize: 1
coreThreadPoolSize: 1
queueCapacity: 1
resilience4j.ratelimiter:
configs:
default:
registerHealthIndicator: false
limitForPeriod: 10
limitRefreshPeriod: 1s
timeoutDuration: 0
eventConsumerBufferSize: 100
instances:
backendA:
baseConfig: default
backendB:
limitForPeriod: 6
limitRefreshPeriod: 500ms
timeoutDuration: 3s
Code to try testing it
SpringBootApplication
public class CircuitsApplication {
private static final Logger logger = LoggerFactory.getLogger(CircuitsApplication.class);
static ResilientClient resilientClient = new ResilientClient();
public static void main(String[] args) {
//SpringApplication.run(CircuitsApplication.class, args);
for (int i = 0; i < 100; i++){
try {
String body = "body content";
String[] headers = new String[]{"header", "value"};
String url = "http://a.bad.url";
String result = resilientClient.processPostRequest(body, headers, url);
logger.info(result);
} catch (Exception ex){
logger.info("Error caught in main loop");
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
I've tried adding the Circuitbreaker annotation to the method itself. I've tried creating a supplier and decorating it. I've tried adding the Bulkhead, removing the Bulkhead. I've tried adding additional fallback methods with different signatures. I've tried with and without @Component.
All I end up getting in my logs is this 100 times:
14:33:10.348 [main] INFO c.t.circuits.CircuitsApplication - Error caught in main loop
I'm not sure what I'm missing. Any help would be greatly appreciated.
