We can specify Hystrix configurations in Spring's application.properties file.

Overriding defaults globally

To override default properties globally use following pattern in application.properties:

hystrix.command.default.<the-property>

Overriding defaults for specific methods

The properties can also be overridden on Hystrix command instance level by specifying a unique value for @HystrixCommand#commandKey and referring to that value by using following pattern in application.properties:

hystrix.command.<commandKey>.<the-property>

Example

Let's use our last example to demonstrate how to use Hystrix configuration in application.properties.

Using @HystrixCommand

package com.logicbig.example;

import com.netflix.hystrix.contrib.javanica.annotation.DefaultProperties;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import org.springframework.stereotype.Service;

@Service
@DefaultProperties
public class MyService {
  @HystrixCommand(fallbackMethod = "defaultDoSomething", commandKey = "doSomethingKey")
  public void doSomething(int input) {
      System.out.println("output: " + 10 / input);
  }

  public void defaultDoSomething(int input, Throwable throwable) {
      System.out.printf("fallback, input:%s, exception:%s%n", input, throwable);
  }
}

application.properties

src/main/resources/application.properties

hystrix.command.doSomethingKey.circuitBreaker.requestVolumeThreshold=2
hystrix.command.doSomethingKey.metrics.rollingStats.timeInMilliseconds=500
hystrix.command.default.circuitBreaker.errorThresholdPercentage=1
hystrix.command.default.circuitBreaker.sleepWindowInMilliseconds=1000

x

Main class

package com.logicbig.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
import org.springframework.context.ConfigurableApplicationContext;
import java.util.concurrent.TimeUnit;

@SpringBootApplication
@EnableCircuitBreaker
public class CircuitBreakerMain {
  public static void main(String[] args) throws InterruptedException {
      ConfigurableApplicationContext ctx = SpringApplication.run(CircuitBreakerMain.class, args);
      MyService myService = ctx.getBean(MyService.class);
      int n = 5;
      for (int i = 0; i < n; i++) {
          myService.doSomething(i < 3 ? 0 : 2);
          TimeUnit.MILLISECONDS.sleep(200);
      }
      TimeUnit.SECONDS.sleep(2);
      System.out.println("-- final call --");
      myService.doSomething(2);
  }
}

Output

fallback, input:0, exception:java.lang.ArithmeticException: / by zero
fallback, input:0, exception:java.lang.ArithmeticException: / by zero
fallback, input:0, exception:java.lang.ArithmeticException: / by zero
fallback, input:2, exception:java.lang.RuntimeException: Hystrix circuit short-circuited and is OPEN
fallback, input:2, exception:java.lang.RuntimeException: Hystrix circuit short-circuited and is OPEN
-- final call --
output: 5

Example Project

Dependencies and Technologies Used:

• Spring Boot 2.1.6.RELEASE
  Corresponding Spring Version 5.1.8.RELEASE
• Spring Cloud Greenwich.SR2
• spring-boot-starter : Core starter, including auto-configuration support, logging and YAML.
• spring-cloud-starter-netflix-hystrix 2.1.2.RELEASE: Spring Cloud Starter Netflix Hystrix.
• JDK 1.8
• Maven 3.5.4