Foreword
SpringCloud micro-service leaders, the best floor plan.
In the micro-services architecture will call each other between the multi-layer service, if there was one failure of the service, the service may result in one or more layers of service
Failure, resulting in total system failure. This phenomenon is called avalanche effect service.
SpringCloud in Hystrix components can solve such problems, Hystrix responsible for monitoring the situation calls between services, has repeatedly failed
Situation fuse protection. Protection method is to use Fallback, when calling the service fails, you can use the Fallback method
The return value; Hystrix interval checks failed service again, if the failure to restore the service, will continue to use the service.
Source
GitHub address: https: //github.com/intomylife/SpringCloud
surroundings
JDK 1.8.0 +
Maven 3.0 +
SpringBoot 2.0.3
SpringCloud Finchley.RELEASE
development tools
IntelliJ IDEA
text
commons project
commons project - POM file
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.0.0
com.zwc
springcloud-hystrix-commons
1.0
springcloud-hystrix-commons
Public works
jar
UTF-8
1.8
Cairo-SR3
Finchley.RELEASE
io.spring.platform
platform-bom
${platform-bom.version}
pom
import
org.springframework.cloud
spring-cloud-dependencies
${spring-cloud-dependencies.version}
pom
import
org.springframework.boot
spring-boot-maven-plugin
Some common configuration dependent
commons project - Project Structure
service project
① There are four modules in this project: a registry and services A, B, C
② A provision of services and service calls B, B calls the service to provide services and C and C to provide services
registry-server (registry)
registry-server - POM file
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.0.0
com.zwc
springcloud-hystrix-service
1.0
com.zwc
springcloud-hystrix-registry-service
1.0
springcloud-hystrix-registry-service
Registry
jar
com.zwc
springcloud-hystrix-commons
1.0
org.springframework.cloud
spring-cloud-starter-netflix-eureka-server
org.springframework.boot
spring-boot-maven-plugin
Mainly added spring-cloud-starter-netflix-eureka-server-dependent
registry-server - application.yml profile
# Port
server:
port: 8761
# Application Name
spring:
application:
name: eurka-server
eureka:
instance:
# Ip instead of using the instance name
prefer-ip-address: true
Examples of the hostname #
hostname: ${spring.cloud.client.ip-address}
Rule # instance ID
instance-id: ${spring.cloud.client.ip-address}:${spring.application.name}:${server.port}
client:
# Whether to register themselves to the registration center
registerWithEureka: false
# Whether to obtain registration information to the registry
fetchRegistry: false
ServiceUrl:
# Registration Center Address
defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
This uses the default port of 8761, of course, can change, but the discovery of registered address of the calling service center side of the port to be consistent with it
registry-server - start class
package com.zwc;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@SpringBootApplication
@EnableEurekaServer
public class SpringcloudHystrixRegistryServiceApplication {
public static void main(String[] args) {
SpringApplication.run(SpringcloudHystrixRegistryServiceApplication.class, args);
}
}
Add @EnableEurekaServer annotation startup class indicates that this project is a registered center
registry-server - to start the project
Visit http 1. Start Project Success: // localhost: 8761 / to see the eureka-server main page
Service Engineering A (providers and consumers)
Service Engineering A - POM file
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.0.0
com.zwc
springcloud-hystrix-a-service
1.0
com.zwc
springcloud-hystrix-a-service-core
1.0
springcloud-hystrix-a-service-core
Service Engineering - A Core
jar
com.zwc
springcloud-hystrix-commons
1.0
com.zwc
springcloud-hystrix-a-service-api
1.0
org.springframework.cloud
spring-cloud-starter-netflix-eureka-client
org.springframework.cloud
spring-cloud-starter-openfeign
org.springframework.boot
spring-boot-maven-plugin
Add spring-cloud-starter-netflix-eureka-client-dependent
Also you need to add Feign start dependent spring-cloud-starter-openfeign
Service Engineering A - application.yml profile
# Port
server:
port: 8090
# Application Name
spring:
application:
name: hystrix-a
eureka:
instance:
# Ip instead of using the instance name
prefer-ip-address: true
Examples of the hostname #
hostname: ${spring.cloud.client.ip-address}
Rule # instance ID
instance-id: ${spring.cloud.client.ip-address}:${spring.application.name}:${server.port}
client:
ServiceUrl:
# Registration Center Address
defaultZone: http://${eureka.instance.hostname}:8761/eureka/
Note here configure registry address port port above 8761 is configured registry project
spring.application.name: application name, need to use is called the consumer, it can also be consumed at the same time consumption
Here three engineering projects in addition to registration centers are similar to this configuration, the port is not the same place and the name of the application, not repeat them
Service Engineering A - application.properties (Note)
# Turn the breaker
feign.hystrix.enabled=true
To take the initiative to open the circuit breaker, will fuse when a service call fails
Here there is a pit, the fuse in this configuration will not take effect written yml
A and B projects have this configuration, the building project to provide services only in C, no consumer services. So do the engineering configuration C
Service Engineering A - controller front controller (service)
package com.zwc.a.controller;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/*
* @ClassName ASayHelloController
* @Desc TODO Say Hello
* @Date 2019/5/20 23:24
* @Version 1.0
*/
@RestController
public class ASayHelloController {
/*
* @ClassName ASayHelloController
* @Desc TODO reads the configuration file port
* @Date 2019/5/20 23:24
* @Version 1.0
*/
@Value("${server.port}")
private String port;
/*
* @ClassName ASayHelloController
* @Desc TODO Say Hello
* @Date 2019/5/20 23:24
* @Version 1.0
*/
@RequestMapping("/a")
public String a(){
return "Hello!I'm a. port：" + port;
}
}
Provide a service: Hello and output ports
Service Engineering A - service call
package com.zwc.a.api.feign;
import com.zwc.a.api.impl.FeignApiFallBack;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
/*
* @ClassName FeignApi
* @Desc TODO using Feign call b - Interface
* @Date 2019/5/20 23:21
* @Version 1.0
*/
@FeignClient(value = "hystrix-b" , fallback = FeignApiFallBack.class)
FeignApi public interface {
/*
* @ClassName FeignApi
* @Desc TODO call b () by hystrix-b service name method
* @Date 2019/5/20 23:21
* @Version 1.0
*/
@RequestMapping("/b")
String b();
}
= "Hystrix-b" to specify which service calls by @FeignClient annotation value
hystrix-b is a provider of spring.application.name: Application Name
To specify the method invoked when blown by @FeignClient annotation fallback = FeignApiFallBack.class
Such a method is FeignApiFallBack (FeignApi) implementation class, a corresponding implementation method is called when such a fuse
b (): This method is a service provided in project B, defined here as the interface
Note that the provider has to return the same value, the same method and the same parameter name
Service Engineering A - Fallback (FeignApiFallBack)
package com.zwc.a.api.impl;
import com.zwc.a.api.feign.FeignApi;
import org.springframework.stereotype.Component;
/*
* @ClassName FeignApi
* @Desc TODO fallback
* @Date 2019/5/20 23:21
* @Version 1.0
*/
@Component
public class implements FeignApiFallBack FeignApi {
/*
* @ClassName FeignApiFallBack
* @Desc TODO call hystrix-b Services b () method fails to perform when
* @Date 2019/5/20 23:31
* @Version 1.0
*/
@Override
public String b() {
return "Hello!aUseB fail";
}
} Wuxi Women's Hospital http://mobile.xasgyy.net/
@Component the use of such notes to Spring Management
FeignApi method implements the interface, providing the corresponding fuse
Service Engineering A - controller front-end controller (Consumer Services)
package com.zwc.a.controller;
import com.zwc.a.api.feign.FeignApi;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/*
* @ClassName AUseBFeignController
* @Desc TODO using Feign call b - Front Controller
* @Date 2019/5/20 23:23
* @Version 1.0
*/
@RestController
public class AUseBFeignController {
@Autowired(required = false)
private FeignApi feignApi;
/*
* @ClassName FeignController
* @Desc TODO call b () by hystrix-b service name method
* @Date 2019/5/20 23:13
* @Version 1.0
*/
@RequestMapping("/aUseB")
public String aUseB(){
return feignApi.b();
}
}
Use @Autowired comment assembly Bean, Bean calls the service by this method in
Such exposure to the external interface call is actually a service provider
Service Engineering A - start class
package com.zwc;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class SpringcloudHystrixAServiceCoreApplication {
public static void main(String[] args) {
SpringApplication.run(SpringcloudHystrixAServiceCoreApplication.class, args);
}
}
Add @EnableEurekaClient comment indicates that this project can provide a service or service call
Add @EnableFeignClients notes indicate on Feign function for remote calls
Engineering Services A - to start the project
1. After starting a successful project visit: http: // localhost: 8090 / a (call your service)
2. outputting content: '! Hello I'm a port:. 8090'
3. Refresh http: // localhost: 8761 / (registry) can see the services have been registered came
4. Visit address: http: // localhost: 8090 / aUseB (call B engineering services)
5. outputting content: '! Hello aUseB fail' (B project has not started at this time because, so the call fallback method)
6. Start service project B, the project started again successful visit: http: // localhost: 8090 / aUseB (call B engineering services)
7. Output content: '! Hello I'm b port:. 8091' (if it is not successful call, wait for a while and then try to refresh)
8. At this time, as evidenced by the success of the fuse
9. access to the address: http: // localhost: 8091 / b (call your service)
10. outputting content: '! Hello I'm b port:. 8091'
11. Refresh again http: // localhost: 8761 / (registry), found that B engineering services also registered came
service project - Project Structure
The multi-use project IntelliJ IDEA Open
The project from GitHub downloaded to your local
Open IntelliJ IDEA
Click File -> Open
Open your downloaded to the local project directory
springcloud-hystrix -> springcloud-hystrix-service (select to open this project)
After opening the service project
Click again File -> Project Structrue
Select Modules, click on the '+' sign
Click Import Module
Or open your downloaded to the local project directory
springcloud-hystrix -> springcloud-hystrix-commons -> pom.xml
Click OK
Click Next, Finish
Click Apply, OK
We hope to be able to help you
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