上一节我们通过单元测试验证了重试的正确性，这一节我们来验证我们线程隔离的正确性，主要包括：
- 验证配置正确加载：即我们在 Spring 配置（例如 application.yml）中的加入的 Resilience4j 的配置被正确加载应用了。
- 相同微服务调用不同实例的时候，使用的是不同的线程（池）。
验证配置正确加载
与之前验证重试类似，我们可以定义不同的 FeignClient，之后检查 resilience4j 加载的线程隔离配置来验证线程隔离配置的正确加载。
并且，与重试配置不同的是，通过系列前面的源码分析，我们知道 spring-cloud-openfeign 的 FeignClient 其实是懒加载的。所以我们实现的线程隔离也是懒加载的，需要先调用，之后才会初始化线程池。所以这里我们需要先进行调用之后，再验证线程池配置。
首先定义两个 FeignClient，微服务分别是 testService1 和 testService2，contextId 分别是 testService1Client 和 testService2Client
@FeignClient(name = "testService1", contextId = "testService1Client")public interface TestService1Client { @GetMapping("/anything") HttpBinAnythingResponse anything();}@FeignClient(name = "testService2", contextId = "testService2Client") public interface TestService2Client { @GetMapping("/anything") HttpBinAnythingResponse anything();}然后，我们增加 Spring 配置，并且给两个微服务都添加一个实例，使用 SpringExtension 编写单元测试类：
//SpringExtension也包含了 Mockito 相关的 Extension，所以 @Mock 等注解也生效了@ExtendWith(SpringExtension.class)@SpringBootTest(properties = { //默认请求重试次数为 3 "resilience4j.retry.configs.default.maxAttempts=3", // testService2Client 里面的所有方法请求重试次数为 2 "resilience4j.retry.configs.testService2Client.maxAttempts=2", //默认线程池配置 "resilience4j.thread-pool-bulkhead.configs.default.coreThreadPoolSize=10", "resilience4j.thread-pool-bulkhead.configs.default.maxThreadPoolSize=10", "resilience4j.thread-pool-bulkhead.configs.default.queueCapacity=1" , //testService2Client 的线程池配置 "resilience4j.thread-pool-bulkhead.configs.testService2Client.coreThreadPoolSize=5", "resilience4j.thread-pool-bulkhead.configs.testService2Client.maxThreadPoolSize=5", "resilience4j.thread-pool-bulkhead.configs.testService2Client.queueCapacity=1",})@Log4j2public class OpenFeignClientTest { @SpringBootApplication @Configuration public static class App { @Bean public DiscoveryClient discoveryClient() { //模拟两个服务实例 ServiceInstance service1Instance1 = Mockito.spy(ServiceInstance.class); ServiceInstance service2Instance2 = Mockito.spy(ServiceInstance.class); Map<String, String> zone1 = Map.ofEntries( Map.entry("zone", "zone1") ); when(service1Instance1.getMetadata()).thenReturn(zone1); when(service1Instance1.getInstanceId()).thenReturn("service1Instance1"); when(service1Instance1.getHost()).thenReturn("www.httpbin.org"); when(service1Instance1.getPort()).thenReturn(80); when(service2Instance2.getInstanceId()).thenReturn("service1Instance2"); when(service2Instance2.getHost()).thenReturn("httpbin.org"); when(service2Instance2.getPort()).thenReturn(80); DiscoveryClient spy = Mockito.spy(DiscoveryClient.class); Mockito.when(spy.getInstances("testService1")) .thenReturn(List.of(service1Instance1)); Mockito.when(spy.getInstances("testService2")) .thenReturn(List.of(service2Instance2)); return spy; } }}编写测试代码，验证配置正确：
@Testpublic void testConfigureThreadPool() { //防止断路器影响 circuitBreakerRegistry.getAllCircuitBreakers().asJava().forEach(CircuitBreaker::reset); //调用下这两个 FeignClient 确保对应的 NamedContext 被初始化 testService1Client.anything(); testService2Client.anything(); //验证线程隔离的实际配置，符合我们的填入的配置 ThreadPoolBulkhead threadPoolBulkhead = threadPoolBulkheadRegistry.getAllBulkheads().asJava() .stream().filter(t -> t.getName().contains("service1Instance1")).findFirst().get(); Assertions.assertEquals(threadPoolBulkhead.getBulkheadConfig().getCoreThreadPoolSize(), 10); Assertions.assertEquals(threadPoolBulkhead.getBulkheadConfig().getMaxThreadPoolSize(), 10); threadPoolBulkhead = threadPoolBulkheadRegistry.getAllBulkheads().asJava() .stream().filter(t -> t.getName().contains("service1Instance2")).findFirst().get(); Assertions.assertEquals(threadPoolBulkhead.getBulkheadConfig().getCoreThreadPoolSize(), 5); Assertions.assertEquals(threadPoolBulkhead.getBulkheadConfig().getMaxThreadPoolSize(), 5);}相同微服务调用不同实例的时候，使用的是不同的线程（池）。
我们需要确保，最后调用（也就是发送 http 请求）的执行的线程池，必须是对应的 ThreadPoolBulkHead 中的线程池。这个需要我们对 ApacheHttpClient 做切面实现，添加注解 @EnableAspectJAutoProxy(proxyTargetClass = true)：
//SpringExtension也包含了 Mockito 相关的 Extension，所以 @Mock 等注解也生效了@ExtendWith(SpringExtension.class)@SpringBootTest(properties = { //默认请求重试次数为 3 "resilience4j.retry.configs.default.maxAttempts=3", // testService2Client 里面的所有方法请求重试次数为 2 "resilience4j.retry.configs.testService2Client.maxAttempts=2", //默认线程池配置 "resilience4j.thread-pool-bulkhead.configs.default.coreThreadPoolSize=10", "resilience4j.thread-pool-bulkhead.configs.default.maxThreadPoolSize=10", "resilience4j.thread-pool-bulkhead.configs.default.queueCapacity=1" , //testService2Client 的线程池配置 "resilience4j.thread-pool-bulkhead.configs.testService2Client.coreThreadPoolSize=5", "resilience4j.thread-pool-bulkhead.configs.testService2Client.maxThreadPoolSize=5", "resilience4j.thread-pool-bulkhead.configs.testService2Client.queueCapacity=1",})@Log4j2public class OpenFeignClientTest { @SpringBootApplication @Configuration @EnableAspectJAutoProxy(proxyTargetClass = true) public static class App { @Bean public DiscoveryClient discoveryClient() { //模拟两个服务实例 ServiceInstance service1Instance1 = Mockito.spy(ServiceInstance.class); ServiceInstance service2Instance2 = Mockito.spy(ServiceInstance.class); Map<String, String> zone1 = Map.ofEntries( Map.entry("zone", "zone1") ); when(service1Instance1.getMetadata()).thenReturn(zone1); when(service1Instance1.getInstanceId()).thenReturn("service1Instance1"); when(service1Instance1.getHost()).thenReturn("www.httpbin.org"); when(service1Instance1.getPort()).thenReturn(80); when(service2Instance2.getInstanceId()).thenReturn("service1Instance2"); when(service2Instance2.getHost()).thenReturn("httpbin.org"); when(service2Instance2.getPort()).thenReturn(80); DiscoveryClient spy = Mockito.spy(DiscoveryClient.class); Mockito.when(spy.getInstances("testService1")) .thenReturn(List.of(service1Instance1)); Mockito.when(spy.getInstances("testService2")) .thenReturn(List.of(service2Instance2)); return spy; } }}拦截 ApacheHttpClient 的 execute 方法，这样可以拿到真正负责 http 调用的线程池，将线程其放入请求的 Header：
@Aspectpublic static class ApacheHttpClientAop { //在最后一步 ApacheHttpClient 切面 @Pointcut("execution(* com.github.jojotech.spring.cloud.webmvc.feign.ApacheHttpClient.execute(..))") public void annotationPointcut() { } @Around("annotationPointcut()") public Object around(ProceedingJoinPoint pjp) throws Throwable { //设置 Header，不能通过 Feign 的 RequestInterceptor，因为我们要拿到最后调用 ApacheHttpClient 的线程上下文 Request request = (Request) pjp.getArgs()[0]; Field headers = ReflectionUtils.findField(Request.class, "headers"); ReflectionUtils.makeAccessible(headers); Map<String, Collection<String>> map = (Map<String, Collection<String>>) ReflectionUtils.getField(headers, request); HashMap<String, Collection<String>> stringCollectionHashMap = new HashMap<>(map); stringCollectionHashMap.put(THREAD_ID_HEADER, List.of(String.valueOf(Thread.currentThread().getName()))); ReflectionUtils.setField(headers, request, stringCollectionHashMap); return pjp.proceed(); }}这样，我们就能拿到具体承载请求的线程的名称，从名称中可以看出他所处于的线程池（格式为“bulkhead-线程隔离名称-n”，例如 bulkhead-testService1Client:www.httpbin.org:80-1），接下来我们就来看下不同的实例是否用了不同的线程池进行调用：
@Testpublic void testDifferentThreadPoolForDifferentInstance() throws InterruptedException { //防止断路器影响 circuitBreakerRegistry.getAllCircuitBreakers().asJava().forEach(CircuitBreaker::reset); Set<String> threadIds = Sets.newConcurrentHashSet(); Thread[] threads = new Thread[100]; //循环100次 for (int i = 0; i < 100; i++) { threads[i] = new Thread(() -> { Span span = tracer.nextSpan(); try (Tracer.SpanInScope cleared = tracer.withSpanInScope(span)) { HttpBinAnythingResponse response = testService1Client.anything(); //因为 anything 会返回我们发送的请求实体的所有内容，所以我们能获取到请求的线程名称 header String threadId = response.getHeaders().get(THREAD_ID_HEADER); threadIds.add(threadId); } }); threads[i].start(); } for (int i = 0; i < 100; i++) { threads[i].join(); } //确认实例 testService1Client:httpbin.org:80 线程池的线程存在 Assertions.assertTrue(threadIds.stream().anyMatch(s -> s.contains("testService1Client:httpbin.org:80"))); //确认实例 testService1Client:httpbin.org:80 线程池的线程存在 Assertions.assertTrue(threadIds.stream().anyMatch(s -> s.contains("testService1Client:www.httpbin.org:80")));}这样，我们就成功验证了，实例调用的线程池隔离。
内容来源网络，如有侵权，联系删除，本文地址：https://www.230890.com/zhan/99871.html
