Current Limit Downgrade
What is Sentinel
With the popularity of microservices, the stability between services and services has become more and more important. Sentinel is a traffic management component for distributed, multilingual and heterogeneous service architectures. It mainly uses traffic as the entry point, from traffic routing, traffic control, traffic shaping, fuse downgrade, system adaptive overload protection, hotspot traffic protection, etc. dimensions to help developers ensure the stability of microservices.
1. Example architecture description
Interface definition:
public interface FooService {
String sayHello(String name);
}
Interface implementation:
@DubboService(timeout = 3000)
public class FooServiceImpl implements FooService {
@Override
public String sayHello(String name) {
return String. format("Hello, %s at %s", name, LocalDateTime. now());
}
}
Current limiting configuration:
FlowRule flowRule = new FlowRule(FooService. class. getName())
.setCount(10)
.setGrade(RuleConstant.FLOW_GRADE_QPS);
FlowRuleManager. loadRules(Collections. singletonList(flowRule));
2. Quick start example
Step 1: Download the source code
git clone -b master https://github.com/apache/dubbo-samples.git
cd ./dubbo-samples-sentinel/
Step 2: Build use cases
Execute the maven command to package the demo project
mvn clean package
Step 3: Start Provider
java -classpath ./target/dubbo-samples-sentinel-1.0-SNAPSHOT.jar org.apache.samples.sentinel.FooProviderBootstrap
Step 4: Start OrderService
java -classpath ./target/dubbo-samples-sentinel-1.0-SNAPSHOT.jar org.apache.samples.sentinel.FooConsumerBootstrap
You can see that in the console output, Blocked means that blocking has started.
Success: Hello, dubbo at 2022-08-08T15:42:40.809
Success: Hello, dubbo at 2022-08-08T15:42:40.812
Success: Hello, dubbo at 2022-08-08T15:42:40.815
Success: Hello, dubbo at 2022-08-08T15:42:40.818
Success: Hello, dubbo at 2022-08-08T15:42:40.821
Success: Hello, dubbo at 2022-08-08T15:42:40.823
Success: Hello, dubbo at 2022-08-08T15:42:40.826
Success: Hello, dubbo at 2022-08-08T15:42:40.828
Success: Hello, dubbo at 2022-08-08T15:42:40.830
Success: Hello, dubbo at 2022-08-08T15:42:40.834
Blocked
Blocked
Blocked
Blocked
Blocked
For more usage methods of Sentinel, please refer to: Sentinel escorts Dubbo services, Sentinel official website
