Hystrix deployment

Reference resources

Java Version implementation : github Address

PHP Version implementation : github Address

Realization

Hystrix Support two ways to realize fuse degradation function ：

• programmatic

• declarative

programmatic

In a programmatic implementation , be based on Hystrix rich API, The setting of circuit breaker is realized by coding .API Users are required to encapsulate different external interactions into command mode objects . During the call , Form a layer of agent ,Hystrix The framework performs periodic takeover on the command object , And determine the circuit breaker status according to the status report obtained in the window .

• Add core dependencies hystrix-core To pom.xml file

<dependency>

<groupId>com.netflix.hystrix</groupId>

<artifactId>hystrix-core</artifactId>

<version>1.5.18</version>

</dependency>

• The package needs to fuse the code logic to Command Class

static class CommandHello extends HystrixCommand<String> {

private final String name;

public CommandHello(String name) {

super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("ExampleGroup"))

.andCommandPropertiesDefaults(HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(3000)));

this.name = name;

}

@Override

protected String runTest() {

return "Hello " + name + "!";

}

// Default fallback method

public String getFallback() {

return "Fallback of Hello was triggered";

}

}

• initialization Command object , And implement execute() Method .

declarative

seeing the name of a thing one thinks of its function , The same effect can be achieved by configuring the declaration , This method has little business intrusion , Automatic code implantation without coding , High business acceptance . This scheme needs to introduce dependencies , And in main class Use notes in EnableHystrix Activate this function .

• Add core dependencies hystrix-javanica To pom.xml file

<dependency>

<groupId>com.netflix.hystrix</groupId>

<artifactId>hystrix-javanica</artifactId>

<version>x.y.z</version>

</dependency>

• Use @HystrixCommand Modify the monitored method , And provide the bottom logic ：

• Introduce... Into the environment HystrixCommandAspect Injection section , Intercept all with HystrixCommand Method of annotation , And generate its proxy object . Business calls do not need to be adjusted , I

spring-cloud-netflix-hystrix Depend on hystrix-javanica , Can make Hystrix Open the box . For the automatic configuration code, see  

@HystrixCommand(fallbackMethod = "fallback_hello", commandProperties = {

@HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "1000")})

public String hello() throws InterruptedException {

System.out.println("Hello");

Thread.sleep(3000);

return "Welcome Hystrix";

}

private String fallback_hello() {

return "Request fails. It takes long time to response";

}

Metrics The bridge

stay Hystrix Design support with plugin The way to bridge metrics To external systems , The plug-in requires inheritance com.netflix.hystrix.strategy.metrics.HystrixMetricsPublisher .

Sample address  

Bridged metrics Can be uniformly exported to actuator Endpoint , And then Prometheus Pull to .