eureka 啟動多個，實作高可用
2，3，4 都向注冊中心進行注冊，每一個子產品都應該使用多個，進行高可用
item和eureka實作高可用
實際情況下，需要在不同主機上進行部署，多台主機，端口号不用修改，但是在一台主機上測試，需要修改端口号
provider高可用配置
8001 端口
java -jar item.jar
java -jar item.jar --server.port=8002
通路兩個端口測試
http://localhost:8001/35
http://localhost:8002/35
成功測試界面：
Eureka高可用配置
兩個配置
主配置和profile同時存在會運作profile,profile是個性配置，主配置是通用配置
euraka1配置
eureka:
instance:
hostname: eureka1
client:
register-with-eureka: true
fetch-registry: true
euraka2配置
eureka:
instance:
hostname: eureka2
client:
register-with-eureka: true
fetch-registry: true
配置連接配接位址、
service-url.defaultZone: http://eureka2:2002/eureka
通路測試：
http://eureka1:2001/
http://eureka2:2002/
eureka用戶端注冊時，向兩個伺服器注冊
修改以下微服務：
sp02-itemservice
sp03-userservice
sp04-orderservice
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
當一個 eureka 服務當機時，仍可以連接配接另一個 eureka 服務
測試連接配接：
06 功能示範項目—遠端調用
06 調用02，03，04
02有叢集，需要負載均衡調用 Ribbon容錯
Ribbon 負載均衡和重試
負載均衡：
遠端調用一個服務，在它的叢集伺服器之間來回調用，分散通路壓力
重試：
一種容錯方式，當調用遠端伺服器失敗，可以自動進行重試調用
遠端調用工具：RestTemplate
Spring 提供的遠端調用工具，執行一個HTTP請求，并獲得響應，一般獲得的是JSON資料
底層有工具API，可将json轉化為java對象
對Rest API調用過程做了高度封裝，一步就可以完成發送請求，處理響應，json轉換
getForObject(url,轉化的類型，送出的參數)
postForObject(url,協定體資料，轉化的類型)
不是springCloud工具是Spring提供的遠端調用工具
Ribbon是對RestTemplate進行了封裝，增強了RestTemplate的功能增強
Ribbon 案例測試
增加配置：
<dependency>
<groupId>cn.tedu</groupId>
<artifactId>sp01-commons</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
RestTemplate
-http協定
-一次請求一次響應，之後斷開連接配接，是一種短連結
-直接連接配接Web(tomcat)伺服器
-調用的是Controller
Dubbo
-java序列化
-長連接配接
-連接配接Dubbo自己的端口（20880 預設）
-調用Service
-Dubbo效率高
1. 建立執行個體對象
1 在啟動類中配置
2 添加一個配置類
2.建立Controller
package cn.tedu.sp06.controller;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.web.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import java.util.List;
@RestController
@Slf4j
public class RibbonController {
@Autowired
private RestTemplate rt;
@GetMapping("/item-service/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId){
//調用遠端服務,調用的是路徑
return rt.getForObject("http://localhost:8001/{1}}", JsonResult.class,orderId);
}
}
通路測試：
調用遠端的user
@GetMapping("/user-service/{userId}")
public JsonResult<User> getUser(@PathVariable Integer userId){
return rt.getForObject("http://localhost:8101/{1}",
JsonResult.class,userId);
}
@GetMapping("/user-service/{userId}/score")
public JsonResult<?> addScore(@PathVariable Integer userId,Integer score){
return rt.getForObject("http://localhost:8101/{1}/score?score={2}",
JsonResult.class,userId,score);
}
調用遠端的訂單
@GetMapping("/order-service/")
public JsonResult<?> addOrder(String orderId){
return rt.getForObject("http://localhost:8201/", JsonResult.class);
}
@GetMapping("/order-service/{orderId}")
public JsonResult<Order> getOrder(@PathVariable String orderId){
return rt.getForObject("http://localhost:8201/{1}", JsonResult.class,orderId);
}
啟動服務
測試eureka:
http://localhost:3001/user-service/7/score?score=100
http://localhost:3001/order-service/123abc
ribbon 重試
pom.xml 添加 spring-retry 依賴
複制代碼到 pom.xml
<dependency>
<groupId>org.springframework.retry</groupId>
<artifactId>spring-retry</artifactId>
</dependency>
yml
spring:
application:
name: ribbon
server:
port: 3001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
ribbon:
MaxAutoRetriesNextServer: 2
MaxAutoRetries: 1
OkToRetryOnAllOperations: true
ConnectionTimeout
ReadTimeout
OkToRetryOnAllOperations=true
預設隻對GET請求重試, 當設定為true時, 對POST等所有類型請求都重試
MaxAutoRetriesNextServer
更換執行個體的次數
MaxAutoRetries
目前執行個體重試次數，嘗試失敗會更換下一個執行個體
主程式設定 RestTemplate 的請求工廠的逾時屬性
package cn.tedu.sp06;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;
@EnableDiscoveryClient
@SpringBootApplication
public class Sp06RibbonApplication {
@LoadBalanced
@Bean
public RestTemplate getRestTemplate() {
SimpleClientHttpRequestFactory f = new SimpleClientHttpRequestFactory();
f.setConnectTimeout(1000);
f.setReadTimeout(1000);
return new RestTemplate(f);
//RestTemplate 中預設的 Factory 執行個體中，兩個逾時屬性預設是 -1，
//未啟用逾時，也不會觸發重試
//return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(Sp06RibbonApplication.class, args);
}
}
item-service 的 ItemController 添加延遲代碼，以便測試 ribbon 的重試機制
package cn.tedu.sp02.item.controller;
import java.util.List;
import java.util.Random;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.service.ItemService;
import cn.tedu.web.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@RestController
public class ItemController {
@Autowired
private ItemService itemService;
@Value("${server.port}")
private int port;
@GetMapping("/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId) throws Exception {
log.info("server.port="+port+", orderId="+orderId);
///--設定随機延遲
if(Math.random()<0.6) {
long t = new Random().nextInt(5000);
log.info("item-service-"+port+" - 暫停 "+t);
Thread.sleep(t);
}
///~~
List<Item> items = itemService.getItems(orderId);
return JsonResult.ok(items).msg("port="+port);
}
@PostMapping("/decreaseNumber")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {
itemService.decreaseNumbers(items);
return JsonResult.ok();
}
}
通路，測試 ribbon 重試機制
通過 ribbon 通路 item-service，當逾時，ribbon 會重試請求叢集中其他伺服器
http://localhost:3001/item-service/35
ribbon的重試機制，在 feign 和 zuul 中進一步進行了封裝，後續可以使用feign或zuul的重試機制
Hystrix 斷路器
微服務當機時，ribbon 無法轉發請求
複制 sp06-ribbon 項目，命名為sp07-hystrix
選擇 sp06-ribbon 項目，ctrl-c，ctrl-v，複制為sp07-hystrix
關閉 sp06-ribbon 項目，後續測試使用 sp07-hystrix 項目
修改 pom.xml
添加 hystrix 起步依賴
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>
修改 application.yml
spring:
application:
name: hystrix
server:
port: 3001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
ribbon:
MaxAutoRetries: 1
MaxAutoRetriesNextServer: 2
OkToRetryOnAllOperations: true
主程式添加 @EnableCircuitBreaker 啟用 hystrix 斷路器
啟動斷路器，斷路器提供兩個核心功能：
降級，逾時、出錯、不可到達時，對服務降級，傳回錯誤資訊或者是緩存資料
熔斷，當服務壓力過大，錯誤比例過多時，熔斷所有請求，所有請求直接降級
可以使用 @SpringCloudApplication 注解代替三個注解
package cn.tedu.sp06;
import org.springframework.boot.SpringApplication;
import org.springframework.cloud.client.SpringCloudApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;
//@EnableCircuitBreaker
//@EnableDiscoveryClient
//@SpringBootApplication
@SpringCloudApplication
public class Sp06RibbonApplication {
@LoadBalanced
@Bean
public RestTemplate getRestTemplate() {
SimpleClientHttpRequestFactory f = new SimpleClientHttpRequestFactory();
f.setConnectTimeout(1000);
f.setReadTimeout(1000);
return new RestTemplate(f);
//RestTemplate 中預設的 Factory 執行個體中，兩個逾時屬性預設是 -1，
//未啟用逾時，也不會觸發重試
//return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(Sp06RibbonApplication.class, args);
}
}
RibbonController 中添加降級方法
為每個方法添加降級方法，例如 getItems() 添加降級方法 getItemsFB()
添加 @HystrixCommand 注解，指定降級方法名
package cn.tedu.sp06.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.pojo.Order;
import cn.tedu.sp01.pojo.User;
import cn.tedu.web.util.JsonResult;
@RestController
public class RibbonController {
@Autowired
private RestTemplate rt;
@GetMapping("/item-service/{orderId}")
@HystrixCommand(fallbackMethod = "getItemsFB") //指定降級方法的方法名
public JsonResult<List<Item>> getItems(@PathVariable String orderId) {
return rt.getForObject("http://item-service/{1}", JsonResult.class, orderId);
}
@PostMapping("/item-service/decreaseNumber")
@HystrixCommand(fallbackMethod = "decreaseNumberFB")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {
return rt.postForObject("http://item-service/decreaseNumber", items, JsonResult.class);
}
/
@GetMapping("/user-service/{userId}")
@HystrixCommand(fallbackMethod = "getUserFB")
public JsonResult<User> getUser(@PathVariable Integer userId) {
return rt.getForObject("http://user-service/{1}", JsonResult.class, userId);
}
@GetMapping("/user-service/{userId}/score")
@HystrixCommand(fallbackMethod = "addScoreFB")
public JsonResult addScore(@PathVariable Integer userId, Integer score) {
return rt.getForObject("http://user-service/{1}/score?score={2}", JsonResult.class, userId, score);
}
/
@GetMapping("/order-service/{orderId}")
@HystrixCommand(fallbackMethod = "getOrderFB")
public JsonResult<Order> getOrder(@PathVariable String orderId) {
return rt.getForObject("http://order-service/{1}", JsonResult.class, orderId);
}
@GetMapping("/order-service")
@HystrixCommand(fallbackMethod = "addOrderFB")
public JsonResult addOrder() {
return rt.getForObject("http://order-service/", JsonResult.class);
}
/
//降級方法的參數和傳回值，需要和原始方法一緻，方法名任意
public JsonResult<List<Item>> getItemsFB(String orderId) {
return JsonResult.err("擷取訂單商品清單失敗");
}
public JsonResult decreaseNumberFB(List<Item> items) {
return JsonResult.err("更新商品庫存失敗");
}
public JsonResult<User> getUserFB(Integer userId) {
return JsonResult.err("擷取使用者資訊失敗");
}
public JsonResult addScoreFB(Integer userId, Integer score) {
return JsonResult.err("增加使用者積分失敗");
}
public JsonResult<Order> getOrderFB(String orderId) {
return JsonResult.err("擷取訂單失敗");
}
public JsonResult addOrderFB() {
return JsonResult.err("添加訂單失敗");
}
}
hystrix 逾時設定
hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds
hystrix等待逾時後, 會執行降級代碼, 快速向用戶端傳回降級結果, 預設逾時時間是1000毫秒
為了測試 hystrix 降級，我們把 hystrix 等待逾時設定得非常小（500毫秒）
此設定一般應大于 ribbon 的重試逾時時長，例如 10 秒
spring:
application:
name: hystrix
server:
port: 3001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
ribbon:
MaxAutoRetriesNextServer: 2
MaxAutoRetries: 1
OkToRetryOnAllOperations: true
hystrix:
command:
default:
execution:
isolation:
thread:
timeoutInMilliseconds: 500
啟動項目進行測試
通過 hystrix 服務，通路可能逾時失敗的 item-service
http://localhost:3001/item-service/35
通過 hystrix 服務，通路未啟動的 user-service
http://localhost:3001/user-service/7
可以看到，如果 item-service 請求逾時，hystrix 會立即執行降級方法
通路 user-service，由于該服務未啟動，hystrix也會立即執行降級方法
hystrix dashboard 斷路器儀表盤
hystrix 對請求的降級和熔斷，可以産生監控資訊，hystrix dashboard可以實時的進行監控
sp07-hystrix 項目添加 actuator，并暴露 hystrix 監控端點
actuator 是 spring boot 提供的服務監控工具，提供了各種監控資訊的監控端點
management.endpoints.web.exposure.include 配置選項，
可以指定端點名，來暴露監控端點
如果要暴露所有端點，可以用 “*”
pom.xml 添加 actuator 依賴
右鍵點選項目或pom.xml, 編輯起步依賴, 添加 actuator 依賴
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
調整 application.yml 配置，并暴露 hystrix.stream 監控端點
spring:
application:
name: hystrix
server:
port: 3001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
ribbon:
MaxAutoRetriesNextServer: 1
MaxAutoRetries: 1
OkToRetryOnAllOperations: true
hystrix:
command:
default:
execution:
isolation:
thread:
timeoutInMilliseconds: 500
management:
endpoints:
web:
exposure:
include: hystrix.stream
通路 actuator 路徑，檢視監控端點
http://localhost:3001/actuator
Hystrix dashboard 儀表盤
建立 sp08-hystrix-dashboard 項目
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.tedu</groupId>
<artifactId>sp08-hystrix-dashboard</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>sp08-hystrix-dashboard</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Hoxton.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
application.yml
spring:
application:
name: hystrix-dashboard
server:
port: 4001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
hystrix:
dashboard:
proxy-stream-allow-list: localhost
主程式添加 @EnableHystrixDashboard 和 @EnableDiscoveryClient
package cn.tedu.sp08;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.hystrix.dashboard.EnableHystrixDashboard;
@EnableDiscoveryClient
@EnableHystrixDashboard
@SpringBootApplication
public class Sp08HystrixDashboardApplication {
public static void main(String[] args) {
SpringApplication.run(Sp08HystrixDashboardApplication.class, args);
}
}
啟動，并通路測試
通路 hystrix dashboard
http://localhost:4001/hystrix
填入 hystrix 的監控端點，開啟監控
http://localhost:3001/actuator/hystrix.stream
通過 hystrix 通路服務多次，觀察監控資訊
http://localhost:3001/item-service/35
http://localhost:3001/user-service/7
http://localhost:3001/user-service/7/score?score=100
http://localhost:3001/order-service/123abc
http://localhost:3001/order-service/