Hystrix Javanica fallback not working in Spring Cloud 1.0 - spring-boot

Question

I built a super simple Hystrix short circuit example based on #spencergibb feign-eureka spring cloud starter example. At first I thought I couldn't get the hystrix javanica default fallbackMethod to trigger due to feign.. now, removing feign, the hystrix default fallbackMethod still doesn't catch exceptions.
pom.xml
<parent>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-parent</artifactId>
<version>1.0.0.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>
:
</dependencies>
Main file:
#SpringBootApplication
#EnableDiscoveryClient
#EnableHystrix
#RestController
public class HelloClientApplication {
#Autowired
HelloClientComponent helloClientComponent;
#RequestMapping("/")
public String hello() {
return helloClientComponent.makeMultipleCalls();
}
public static void main(String[] args) {
SpringApplication.run(HelloClientApplication.class, args);
}
}
HelloClientComponent.java (created because I know javanica expects to be inside a spring managed component or service):
#Component
public class HelloClientComponent {
#Autowired
RestTemplate restTemplate;
public String makeMultipleCalls() {
int cnt=20;
StringBuilder sb = new StringBuilder();
while (cnt-- > 0) {
String response = theServerRequestRoot();
sb.append(response).append(" ");
}
return sb.toString();
}
public String theServersRequestRootFallback() {
System.out.println("BOMB!!!!!!");
return "BOMB!!!!!!";
}
#HystrixCommand(fallbackMethod = "theServersRequestRootFallback", commandKey = "callToServers")
public String theServerRequestRoot() {
ResponseEntity<String> result = restTemplate.getForEntity("http://HelloServer", String.class);
System.out.println(result.getBody());
return result.getBody();
}
}
I start 2 servers, one which always succeeds and responds, and the other will fail 30% of the time with a 500 error. When I curl this client (to '/') things go normally for the non-forced failure calls. Round robining works fine as well. When the second server does return the 500 error, the fallbackMethod does not get called and the curl to '/' ends and returns with an error.
Update with solution per Spencer and Dave's suggestions. Change to the following:
Main Application file:
#SpringBootApplication
#EnableDiscoveryClient
#EnableHystrix
#RestController
public class HelloClientApplication {
#Autowired
HelloClientComponent helloClientComponent;
#RequestMapping("/")
public String hello() {
int cnt=20;
StringBuilder sb = new StringBuilder();
while (cnt-- > 0) {
String response = helloClientComponent.theServerRequestRoot(); // call directly to #Component in order for #HystrixCommand to intercept via AOP
sb.append(response).append(" ");
}
return sb.toString();
}
public static void main(String[] args) {
SpringApplication.run(HelloClientApplication.class, args);
}
}
HelloClientComponent.java:
#Component
public class HelloClientComponent {
#Autowired
RestTemplate restTemplate;
public String theServersRequestRootFallback() {
System.out.println("BOMB!!!!!!");
return "BOMB!!!!!!";
}
#HystrixCommand(fallbackMethod = "theServersRequestRootFallback", commandKey = "callToServers")
public String theServerRequestRoot() {
ResponseEntity<String> result = restTemplate.getForEntity("http://HelloServer", String.class);
System.out.println(result.getBody());
return result.getBody();
}
}

Answer 1

#HystrixCommand only works because Spring makes a proxy to call that method on. If you call the method from within the proxy it doesn't go through the interceptor. You need to call the #HystrixCommand from another #Component (or use AspectJ).