简介
ratelimiter限制了服务被调用的次数，每隔一段时间重置该次数，服务在超出等待时间之后返回异常或者fallback方法
配置介绍
| 配置属性 | 默认值 | 描述 |
|---|---|---|
| limitRefreshPeriod | 500ns | 时间段，每隔该时间段，服务被调用的总次数重置 |
| limitForPeriod | 50 | 每个时间段内服务可以被调用的最大总次数 |
| timeoutDuration | 5s | 等待调用服务的时间，超出时间返回异常 |
演示使用
- 创建一个模拟的外部服务，服务执行完成需要2s的时间
- 自定义RateLimiterConfig，每5s服务只能调用5次，调用等待时间为10s
- 每隔50ms开启一个新线程调用外部服务
需要准备的依赖包，resilience4j的spring boot包，里面包括了resilience4j所有功能的包和自动配置功能
<dependency>
<groupId>io.github.resilience4j</groupId>
<artifactId>resilience4j-spring-boot2</artifactId>
<version>1.7.0</version>
</dependency>
模拟服务
服务执行2s，打印时间和当前线程名称后返回
@Service
public class ExternalLowRateService {
public void callService() {
try {
Thread.sleep(2000);
System.out.println(LocalTime.now() + " Call processing finished = " + Thread.currentThread().getName());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
ratelimiter配置和使用
@SpringBootTest
class ExternalLowRateServiceTest {
@Autowired
ExternalLowRateService service;
@Test
void callService() throws InterruptedException {
/*
自定义RateLimiterConfig, 限制服务调用次数为5，每隔5s重置，最大等待时间为10s
*/
RateLimiterConfig config = RateLimiterConfig.custom()
.limitRefreshPeriod(Duration.ofSeconds(5))
.limitForPeriod(5)
.timeoutDuration(Duration.ofSeconds(10))
.build();
RateLimiter rateLimiter = RateLimiter.of("externalLowRateService", config);
for (int i = 1; i <= 20; i++) {
System.out.println(LocalTime.now() + " Starting service call = " + i);
// 使用rateLimiter调用外部服务
new Thread(() -> rateLimiter.executeRunnable(service::callService),"service-call-" + i).start();
Thread.sleep(50);
}
Thread.sleep(12000);
}
}
输出结果
- 1-20次调用依次开始
- 1-5次开始执行并返回
- 5s后6-10次开始执行并返回
- 16-20次调用已等待超过10s，返回异常
- 11-15次调用执行并返回
04:41:12.846114900 Starting service call = 1
04:41:12.914934300 Starting service call = 2
04:41:12.977763900 Starting service call = 3
04:41:13.041593400 Starting service call = 4
04:41:13.104454900 Starting service call = 5
04:41:13.166494600 Starting service call = 6
04:41:13.230321600 Starting service call = 7
04:41:13.293139600 Starting service call = 8
04:41:13.355637600 Starting service call = 9
04:41:13.417592800 Starting service call = 10
04:41:13.480228600 Starting service call = 11
04:41:13.542253700 Starting service call = 12
04:41:13.604270 Starting service call = 13
04:41:13.665588600 Starting service call = 14
04:41:13.728248400 Starting service call = 15
04:41:13.789320300 Starting service call = 16
04:41:13.850204 Starting service call = 17
04:41:13.912728400 Starting service call = 18
04:41:13.975277900 Starting service call = 19
04:41:14.038369600 Starting service call = 20
04:41:14.859399800 Call processing finished = service-call-1
04:41:14.921328200 Call processing finished = service-call-2
04:41:14.983447400 Call processing finished = service-call-3
04:41:15.045475300 Call processing finished = service-call-4
04:41:15.107320600 Call processing finished = service-call-5
04:41:19.864071500 Call processing finished = service-call-9
04:41:19.864071500 Call processing finished = service-call-6
04:41:19.864071500 Call processing finished = service-call-8
04:41:19.864071500 Call processing finished = service-call-10
04:41:19.864071500 Call processing finished = service-call-7
Exception in thread "service-call-16" io.github.resilience4j.ratelimiter.RequestNotPermitted: RateLimiter 'externalLowRateService' does not permit further calls
at io.github.resilience4j.ratelimiter.RequestNotPermitted.createRequestNotPermitted(RequestNotPermitted.java:43)
at io.github.resilience4j.ratelimiter.RateLimiter.waitForPermission(RateLimiter.java:591)
at io.github.resilience4j.ratelimiter.RateLimiter.lambda$decorateCheckedRunnable$3(RateLimiter.java:246)
at io.vavr.CheckedRunnable.lambda$unchecked$0(CheckedRunnable.java:68)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:872)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:862)
at io.ysh.eurekacientconsumer.service.ExternalLowRateServiceTest.lambda$callService$0(ExternalLowRateServiceTest.java:29)
at java.base/java.lang.Thread.run(Thread.java:834)
Exception in thread "service-call-17" io.github.resilience4j.ratelimiter.RequestNotPermitted: RateLimiter 'externalLowRateService' does not permit further calls
at io.github.resilience4j.ratelimiter.RequestNotPermitted.createRequestNotPermitted(RequestNotPermitted.java:43)
at io.github.resilience4j.ratelimiter.RateLimiter.waitForPermission(RateLimiter.java:591)
at io.github.resilience4j.ratelimiter.RateLimiter.lambda$decorateCheckedRunnable$3(RateLimiter.java:246)
at io.vavr.CheckedRunnable.lambda$unchecked$0(CheckedRunnable.java:68)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:872)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:862)
at io.ysh.eurekacientconsumer.service.ExternalLowRateServiceTest.lambda$callService$0(ExternalLowRateServiceTest.java:29)
at java.base/java.lang.Thread.run(Thread.java:834)
Exception in thread "service-call-18" io.github.resilience4j.ratelimiter.RequestNotPermitted: RateLimiter 'externalLowRateService' does not permit further calls
at io.github.resilience4j.ratelimiter.RequestNotPermitted.createRequestNotPermitted(RequestNotPermitted.java:43)
at io.github.resilience4j.ratelimiter.RateLimiter.waitForPermission(RateLimiter.java:591)
at io.github.resilience4j.ratelimiter.RateLimiter.lambda$decorateCheckedRunnable$3(RateLimiter.java:246)
at io.vavr.CheckedRunnable.lambda$unchecked$0(CheckedRunnable.java:68)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:872)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:862)
at io.ysh.eurekacientconsumer.service.ExternalLowRateServiceTest.lambda$callService$0(ExternalLowRateServiceTest.java:29)
at java.base/java.lang.Thread.run(Thread.java:834)
Exception in thread "service-call-19" io.github.resilience4j.ratelimiter.RequestNotPermitted: RateLimiter 'externalLowRateService' does not permit further calls
at io.github.resilience4j.ratelimiter.RequestNotPermitted.createRequestNotPermitted(RequestNotPermitted.java:43)
at io.github.resilience4j.ratelimiter.RateLimiter.waitForPermission(RateLimiter.java:591)
at io.github.resilience4j.ratelimiter.RateLimiter.lambda$decorateCheckedRunnable$3(RateLimiter.java:246)
at io.vavr.CheckedRunnable.lambda$unchecked$0(CheckedRunnable.java:68)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:872)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:862)
at io.ysh.eurekacientconsumer.service.ExternalLowRateServiceTest.lambda$callService$0(ExternalLowRateServiceTest.java:29)
at java.base/java.lang.Thread.run(Thread.java:834)
Exception in thread "service-call-20" io.github.resilience4j.ratelimiter.RequestNotPermitted: RateLimiter 'externalLowRateService' does not permit further calls
at io.github.resilience4j.ratelimiter.RequestNotPermitted.createRequestNotPermitted(RequestNotPermitted.java:43)
at io.github.resilience4j.ratelimiter.RateLimiter.waitForPermission(RateLimiter.java:591)
at io.github.resilience4j.ratelimiter.RateLimiter.lambda$decorateCheckedRunnable$3(RateLimiter.java:246)
at io.vavr.CheckedRunnable.lambda$unchecked$0(CheckedRunnable.java:68)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:872)
at io.github.resilience4j.ratelimiter.RateLimiter.executeRunnable(RateLimiter.java:862)
at io.ysh.eurekacientconsumer.service.ExternalLowRateServiceTest.lambda$callService$0(ExternalLowRateServiceTest.java:29)
at java.base/java.lang.Thread.run(Thread.java:834)
04:41:24.863851800 Call processing finished = service-call-12
04:41:24.863851800 Call processing finished = service-call-15
04:41:24.863851800 Call processing finished = service-call-11
04:41:24.863851800 Call processing finished = service-call-14
04:41:24.863851800 Call processing finished = service-call-13
springboot自动配置
配置在application.yml中
- configs：ratelimiter配置，可以配置多个
- instances：ratelimiter实例名称，可以配置baseConfig指定具体的ratelimiter配置，也可以自行配置
resilience4j.ratelimiter:
configs:
default:
limitForPeriod: 10
limitRefreshPeriod: 1s
instances:
externalLowRateService:
limitForPeriod: 5
limitRefreshPeriod: 5s
timeoutDuration: 10s
注解
注解@Bulkhead有两个属性：
- name：ratelimiter的名称，对应yml文件中instances中的配置
- fallbackMethod：方法名，超出等待时间的服务调用会执行该方法并返回
@Service
public class ExternalLowRateService {
@RateLimiter(name = "externalLowRateService")
public void callService() {
try {
Thread.sleep(2000);
System.out.println(LocalTime.now() + " Call processing finished = " + Thread.currentThread().getName());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
测试方法
测试方法，没有显式的bulkhead配置和创建，直接执行服务调用即可，结果返回跟上面的测试一样
@SpringBootTest
class ExternalLowRateServiceTest {
@Autowired
ExternalLowRateService service;
@Test
void callService() throws InterruptedException {
for (int i = 1; i <= 20; i++) {
System.out.println(LocalTime.now() + " Starting service call = " + i);
new Thread(service::callService,"service-call-" + i).start();
Thread.sleep(50);
}
Thread.sleep(12000);
}
}
