1 准备环境
1.1 准备商品微服务和订单微服务
- 其中商品微服务的findById()方法设置休眠2秒，用来模拟网络波动等情况：
package com.sunxiaping.product.controller;
import com.sunxiaping.product.domain.Product;
import com.sunxiaping.product.service.ProductService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
@RestController
@RequestMapping(value = "/product")
public class ProductController {
@Autowired
private ProductService productService;
@Value("${server.port}")
private String port;
@Value("${spring.cloud.client.ip-address}")
private String ip;
@PostMapping(value = "/save")
public String save(@RequestBody Product product) {
productService.save(product);
return "新增成功";
}
@GetMapping(value = "/findById/{id}")
public Product findById(@PathVariable(value = "id") Long id) {
try {
//休眠2秒，用来模拟 网络波动等情况
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Product product = productService.findById(id);
product.setProductName("访问的地址是：" + ip + ":" + port);
return product;
}
}
server:
port: 9002 # 微服务的端口号
tomcat:
max-threads: 10 # 最大线程数是10
spring:
application:
name: service-order # 微服务的名称
datasource:
url: jdbc:mysql://192.168.1.57:3306/test?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&serverTimezone=GMT%2B8&allowPublicKeyRetrieval=true
driver-class-name: com.mysql.cj.jdbc.Driver
username: root
password: 123456
jpa:
generate-ddl: true
show-sql: true
open-in-view: true
database: mysql
jmx:
unique-names: true
# 配置Eureka
eureka:
instance:
# 实例的名称
instance-id: service-order:9002
# 显示IP信息
prefer-ip-address: true
lease-renewal-interval-in-seconds: 5 # 发送心跳续约间隔（默认30秒）
lease-expiration-duration-in-seconds: 10 # Eureka Client发送心跳给Eureka Server端后，续约到期时间（默认90秒）
client:
healthcheck:
enabled: true
service-url: # Eureka Server的地址
# defaultZone: http://localhost:9000/eureka/
defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/
# Ribbon的重试机制
service-product:
ribbon:
# 修改ribbon的负载均衡策略 服务名 - ribbon - NFLoadBalancerRuleClassName ：负载均衡策略
# NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule # 修改ribbon的负载均衡策略为权重策略
# Ribbon的重试机制参数
ConnectTimeout: 250 # Ribbon的连接超时时间
ReadTimeout: 1000 # Ribbon的数据读取超时时间
OkToRetryOnAllOperations: true # 是否对所有操作都进行重试
MaxAutoRetriesNextServer: 50 # 切换实例的重试次数
MaxAutoRetries: 1 # 对当前实例的重试次数
# 微服务info内容详细信息
info:
app.name: xxx
company.name: xxx
build.artifactId: $project.artifactId$
build.version: $project.version$
# 开启日志debug
logging:
level:
root: info
package com.sunxiaping.order.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
@Configuration
public class SpringConfig {
@Bean
// @LoadBalanced
public RestTemplate restTemplate() {
return new RestTemplate();
}
}
- 订单微服务的OrderController.java
package com.sunxiaping.order.controller;
import com.sunxiaping.order.domain.Product;
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.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
@RestController
@RequestMapping(value = "/order")
public class OrderController {
@Autowired
private RestTemplate restTemplate;
/**
* @param id
* @return
*/
@GetMapping(value = "/buy/{id}")
public Product buy(@PathVariable(value = "id") Long id) {
Product product = restTemplate.getForObject("http://localhost:9001/product/findById/" + id, Product.class);
return product;
}
@GetMapping(value = "/findOrder")
public String findOrder() {
return "商品查询到了";
}
}
2 使用Jmeter测试接口
![使用Jmeter测试接口]()
3 系统负载过高存在的问题
3.1 问题分析
-
在微服务架构中，我们将业务拆成一个个的服务，服务和服务之间可以相互调用，由于网络原因或者自身的原因，服务并不能保证100%可用，如果单个服务出现问题，调用这个服务就会出现网络延迟，此时如果有大量的网络请求涌入，会形成任务累计，导致服务瘫痪。
-
换句话说，Tomcat等容器会以线程池的方式对所有的请求进行统一的管理，如果某个方法可能存着耗时问题，随着外面积压的请求越来越多，势必会造成系统的崩溃、瘫痪等。
![Tomcat容器以线程数的方式管理所有线程]()
4 线程池隔离的方式处理积压问题
4.1 在订单微服务中引入相关jar包的Maven坐标
<dependency>
<groupId>com.netflix.hystrix</groupId>
<artifactId>hystrix-metrics-event-stream</artifactId>
<version>1.5.12</version>
</dependency>
<dependency>
<groupId>com.netflix.hystrix</groupId>
<artifactId>hystrix-javanica</artifactId>
<version>1.5.12</version>
</dependency>
4.2 配置线程池
- 配置HystrixCommand接口的实现类，在实现类中可以对线程池进行配置：
package com.sunxiaping.order.command;
import com.netflix.hystrix.*;
import com.sunxiaping.order.domain.Product;
import org.springframework.web.client.RestTemplate;
public class OrderCommand extends HystrixCommand<Product> {
private RestTemplate restTemplate;
private Long id;
public OrderCommand(RestTemplate restTemplate, Long id) {
super(setter());
this.restTemplate = restTemplate;
this.id = id;
}
private static Setter setter() {
// 服务分组
HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey("order_product");
// 服务标识
HystrixCommandKey commandKey = HystrixCommandKey.Factory.asKey("product");
// 线程池名称
HystrixThreadPoolKey threadPoolKey = HystrixThreadPoolKey.Factory.asKey("order_product_pool");
/**
* 线程池配置
* withCoreSize : 线程池大小为10
* withKeepAliveTimeMinutes: 线程存活时间15秒
* withQueueSizeRejectionThreshold :队列等待的阈值为100,超过100执行拒绝策略
*/
HystrixThreadPoolProperties.Setter threadPoolProperties = HystrixThreadPoolProperties.Setter().withCoreSize(50)
.withKeepAliveTimeMinutes(15).withQueueSizeRejectionThreshold(100);
// 命令属性配置Hystrix 开启超时
HystrixCommandProperties.Setter commandProperties = HystrixCommandProperties.Setter()
// 采用线程池方式实现服务隔离
.withExecutionIsolationStrategy(HystrixCommandProperties.ExecutionIsolationStrategy.THREAD)
// 禁止
.withExecutionTimeoutEnabled(false);
return Setter.withGroupKey(groupKey).andCommandKey(commandKey).andThreadPoolKey(threadPoolKey)
.andThreadPoolPropertiesDefaults(threadPoolProperties).andCommandPropertiesDefaults(commandProperties);
}
@Override
protected Product run() throws Exception {
System.out.println(Thread.currentThread().getName());
return restTemplate.getForObject("http://localhost:9001/product/findById/" + id, Product.class);
}
/**
* 服务降级
*
* @return
*/
@Override
protected Product getFallback() {
Product product = new Product();
product.setProductName("不好意思，出错了");
return product;
}
}
4.3 修改Controller
package com.sunxiaping.order.controller;
import com.sunxiaping.order.command.OrderCommand;
import com.sunxiaping.order.domain.Product;
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.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
@RestController
@RequestMapping(value = "/order")
public class OrderController {
@Autowired
private RestTemplate restTemplate;
/**
* 使用OrderCommand调用远程远程服务
*
* @param id
* @return
*/
@GetMapping(value = "/buy/{id}")
public Product buy(@PathVariable(value = "id") Long id) {
return new OrderCommand(restTemplate, id).execute();
}
@GetMapping(value = "/findOrder")
public String findOrder() {
System.out.println(Thread.currentThread().getName());
return "商品查询到了";
}
}
