Sentinel dashboard的使用
往期文章
- Nacos环境搭建
- Nacos注册中心的使用
- Nacos配置中心的使用
- Sentinel 容灾中心的使用
参考文档
Sentinel · alibaba/spring-cloud-alibaba Wiki · GitHub
限流结果
下载sentinel-dashboard
github地址:Sentinel/sentinel-dashboard at master · alibaba/Sentinel · GitHub
启动脚本
创建sentinel-dashboard的启动脚本,并添加如下信息:
java -jar -Dserver.port=8350 -Dcsp.sentinel.dashboard.server=localhost:8350 -Dproject.name=sentinel-dashboard --add-exports=java.base/sun.net.util=ALL-UNNAMED sentinel-dashboard-1.8.4.jar
目录:
Jar(客户端)
<!-- 一定要放在前面 -->
<!--Sentinel -->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>
<!-- sentinel-dashboard -->
<dependency>
<groupId>com.alibaba.csp</groupId>
<artifactId>sentinel-transport-simple-http</artifactId>
</dependency>
<!--Spring Cloud Alibaba Nacos Discovery-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<!--Spring Cloud Alibaba Nacos Config-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>
<!--LoadBalancer-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-loadbalancer</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
yml
注意:sentinel-dashboard默认会在8720端口接收注册服务的数据,所以dashboard使用的端口和接收数据的端口不要一样。
消费者
server:
port: 8581
spring:
application:
name: nacos-consumer
cloud:
nacos:
config:
group: DEFAULT_GROUP
server-addr: localhost:8848
sentinel:
transport:
port: 8720
dashboard: localhost:8350
eager: true
config:
import:
# 父类配置要放在前面,相同的项会被后面的配置覆盖
- optional:nacos:nacos-discovery.yaml
management:
endpoints:
web:
exposure:
include: '*'
nacos-discovery.yml
spring:
cloud:
nacos:
discovery:
server-addr: localhost:8848
username: devilvan
password: 741258963hjkl
failure-tolerance-enabled: true
Sentinel Dashboard的使用
1. 关闭服务端硬编码的限流规则
服务端的代码参考:Sentinel 容灾中心的使用
2. 在dashboard中设置限流规则(不推荐)
不推荐的原因,客户端、服务端重启后规则不会保存
3. 限流效果:
Nacos配置并保存Sentinel限流规则
步骤
- 引入sentinel和sentinel dashboard相关依赖
- 服务端给对应controller添加
@SentinelResource
注解,并定义一个限流/熔断处理类负责处理该resource的限流/熔断逻辑(注:方法必须有static修饰)。 - Nacos配置中心保存sentinel resource的配置信息,即限流规则
Jar(服务端)
<!-- 一定要放在前面 -->
<!--Sentinel -->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>
<!-- SpringCloud Alibaba CircuitBreaker Sentinel-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-circuitbreaker-sentinel</artifactId>
</dependency>
<!-- sentinel-dashboard -->
<dependency>
<groupId>com.alibaba.csp</groupId>
<artifactId>sentinel-transport-simple-http</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.csp</groupId>
<artifactId>sentinel-datasource-nacos</artifactId>
<version>${sentinel-version}</version>
</dependency>
<dependency>
<groupId>com.alibaba.csp</groupId>
<artifactId>sentinel-spring-webmvc-adapter</artifactId>
<version>${sentinel-version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<!--Spring Cloud Alibaba Nacos Discovery-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<!--Spring Cloud Alibaba Nacos Config-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>
yml(服务端)
server:
port: 8481
spring:
application:
name: nacos-provider
cloud:
nacos:
config:
group: DEFAULT_GROUP
server-addr: localhost:8848
discovery:
server-addr: localhost:8848
username: devilvan
password: 741258963hjkl
sentinel:
transport:
port: 8720
dashboard: localhost:8350
eager: true
datasource:
echo:
nacos:
server-add: ${spring.cloud.nacos.config.server-addr}
groupId: ${spring.cloud.nacos.config.group}
dataId: ${spring.application.name}-rules
rule-type: flow
data-type: json
config:
import:
# 父类配置要放在前面,相同的项会被后面的配置覆盖
- optional:nacos:nacos-discovery.yaml
management:
endpoints:
web:
exposure:
include: '*'
Nacos配置并保存Sentinel限流规则
1. Nacos配置中心添加配置文件
注:建议单独起resource的名字,不要将路由信息当做resource
[
{
"resource": "echo",
"limitApp": "default",
"grade": 1,
"count": 1,
"strategy": 0,
"controlBehavior": 0,
"clusterMode": false
},
{
"resource": "echo2",
"limitApp": "default",
"grade": 1,
"count": 1,
"strategy": 0,
"controlBehavior": 0,
"clusterMode": false
}
]
2. 服务端后台代码
注意:echo2()
方法是通过代码层面的try catch
来进行限流/熔断的,在nacos配置中定义的echo2的resource不能在该处添加@SentinelResource注解
/**
* @Description Nacos生产者 控制层
*/
@RestController
@RequestMapping(value = "nacosProviderController")
public class NacosProviderController {
@Resource(name = "nacosProviderServiceImpl")
private NacosProviderService nacosProviderService;
@GetMapping(value = "/echo/{str}")
@SentinelResource(value = "echo", fallback = "echoFallback", fallbackClass = EchoFallback.class,
blockHandler = "echoBlockHandler", blockHandlerClass = EchoFallback.class)
public ResultMessage<String> echo(@PathVariable String str) {
return nacosProviderService.echo(str);
}
@GetMapping(value = "/echo2/{str}")
public ResultMessage<String> echo2(@PathVariable String str) {
return nacosProviderService.echo2(str);
}
}
3. 限流/熔断处理类
注意:该类中的限流/熔断方法必须static修饰
/**
* @Description echo方法 异常回调类
*/
public class EchoFallback {
/**
* 遇到异常走的逻辑
*
* @param str 原方法的参数
* @param e 异常信息
* @return 异常回调方法返回值,和原方法返回值一致
*/
public static ResultMessage<String> echoFallback(String str, Throwable e) {
ResultMessage<String> resultMessage = new ResultMessage<>();
String message = "熔断-echo方法调用异常,str: " + str + "\n" + e;
resultMessage.setMessage(message);
return resultMessage;
}
/**
* 方法限流逻辑
*
* @param str 原方法的参数
* @param e 异常信息
* @return 限流回调方法返回值,和原方法返回值一致
*/
public static ResultMessage<String> echoBlockHandler(String str, BlockException e) {
ResultMessage<String> resultMessage = new ResultMessage<>();
String message = "限流-echo方法进行 限流,str: " + str + "\n" + e;
resultMessage.setMessage(message);
return resultMessage;
}
}
4. 生产者业务逻辑代码
注:echo2()
方法中使用的是sentinel的api实现限流,高亮的部分需要指定配置文件中已存在,或在代码中定义限流规则的resource,即"echo2"资源需要对应上方Nacos配置文件中的resource。
/**
* @Description Nacos生产者 业务逻辑实现类
*/
@Service
public class NacosProviderServiceImpl implements NacosProviderService {
/**
* 测试限流/熔断的方法
*
* @param str 原方法的参数
* @return 回调
*/
@Override
public ResultMessage<String> echo(String str) {
ResultMessage<String> resultMessage = new ResultMessage<>();
if ("devilvan".equals(str)) {
String msg = "Hello Nacos Discovery " + str;
resultMessage.setMessage(msg);
} else {
throw new RuntimeException();
}
return resultMessage;
}
/**
* 测试sentinel设置资源并使用的方法
*
* @param str 入参字符串
* @return 回调
*/
@Override
public ResultMessage<String> echo2(String str) {
String resource = "echo2";
ResultMessage<String> resultMessage = new ResultMessage<>();
Entry entry = null;
try {
entry = SphU.entry(resource);
if ("devilvan".equals(str)) {
String msg = "Hello Nacos Discovery " + str;
resultMessage.setMessage(msg);
} else {
throw new RuntimeException();
}
} catch (BlockException e) {
String msg = "限流-echo2方法调用异常,str: " + str + "\n" + e;
resultMessage.setMessage(msg);
} catch (Exception e) {
String msg = "熔断-echo2方法调用异常,str: " + str + "\n" + e;
resultMessage.setMessage(msg);
} finally {
if (entry != null) {
entry.exit();
}
}
return resultMessage;
}
}