Hystrix fault tolerance

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Update time: 2020-03-03

SOFARPC is integrated Hystrix provides fuse capability and is currently available in the first preview version. More information about Hystrix can be found in Hystrix Official Documentation, Hystrix integration capabilities are provided primarily by ScienJus, thanks for contribution.

Next, let’s talk about how to experience the fuse capability of Hystrix. The following example uses the SOFARPC 5.5.0 version. More Hystrix configuration and SOFABoot integration usage will be provided in subsequent releases, so stay tuned.

Work preparation

The Hystrix module is not loaded directly as an optional module by default. If you need to use it, you need to actively add the Hystrix maven dependency:

<dependency>
        <groupId>com.netflix.hystrix</groupId>
        <artifactId>hystrix-core</artifactId>
        <version>1.5.12</version>
</dependency>

By explicitly opening Hystrix by configuration, HystrixFilter will be loaded automatically:

// Open globally
RpcConfigs.putValue(HystrixConstants.SOFA_HYSTRIX_ENABLED, true);
// Open for a specific Consumer
ConsumerConfig<HelloService> consumerConfig = new ConsumerConfig<HelloService>()
        .setInterfaceId(HelloService.class.getName())
        .setParameter(HystrixConstants.SOFA_HYSTRIX_ENABLED, String.valueOf(true));

FallbackFactory

The FallbackFactory interface mainly provides the injection capability of the Fallback implementation, which is used to automatically perform the degraded logic when Hystrix executes an exception (throws an exception, timeout, thread pool rejection, and blown).

Define the interface Fallback implementation:

public class HelloServiceFallback implements HelloService {
    @Override
    public String sayHello(String name, int age) {
        return "fallback " + name + " from server! age: " + age;
    }
}

Inject Fallback implementation:

ConsumerConfig<HelloService> consumerConfig = new ConsumerConfig<HelloService>()
        .setInterfaceId(HelloService.class.getName())
        .setParameter(HystrixConstants.SOFA_HYSTRIX_ENABLED, String.valueOf(true));
// You can directly inject Fallback implementation directly using the default FallbackFactory
SofaHystrixConfig.registerFallback(consumerConfig, new HelloServiceFallback());
// You can also customize FallbackFactory to directly inject FallbackFactory
SofaHystrixConfig.registerFallbackFactory(consumerConfig, new HelloServiceFallbackFactory());

When the server responds with a failure, the client automatically triggers the Fallback logic execution.

SetterFactory

SetterFactory provides Hystrix fine-grained configuration capabilities. SOFARPC has provided the default DefaultSetterFactory to generate the Setter for each caller. If there is a more customized description, it can also be provided for each ConsumerConfig. Customize SetterFactory.

SofaHystrixConfig.registerSetterFactory(consumerConfig, new CustomSetterFactory());

In the implementation provided by default, GroupKey is InterfaceId, and CommandKey is the name of the method.

Support Hystrix version information

SOFARPC: 5.5.0, SOFABoot: 2.5.3。

SOAF RPC Integration Verification Hystrix version: 1.5.12.