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dubbo中ForkingClusterInvoker的作用是什么

发表于:2025-12-02 作者:千家信息网编辑
千家信息网最后更新 2025年12月02日,这期内容当中小编将会给大家带来有关dubbo中ForkingClusterInvoker的作用是什么,文章内容丰富且以专业的角度为大家分析和叙述,阅读完这篇文章希望大家可以有所收获。ForkingCl
千家信息网最后更新 2025年12月02日dubbo中ForkingClusterInvoker的作用是什么

这期内容当中小编将会给大家带来有关dubbo中ForkingClusterInvoker的作用是什么,文章内容丰富且以专业的角度为大家分析和叙述,阅读完这篇文章希望大家可以有所收获。

ForkingClusterInvoker

dubbo-2.7.3/dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/support/ForkingClusterInvoker.java

public class ForkingClusterInvoker extends AbstractClusterInvoker {    /**     * Use {@link NamedInternalThreadFactory} to produce {@link org.apache.dubbo.common.threadlocal.InternalThread}     * which with the use of {@link org.apache.dubbo.common.threadlocal.InternalThreadLocal} in {@link RpcContext}.     */    private final ExecutorService executor = Executors.newCachedThreadPool(            new NamedInternalThreadFactory("forking-cluster-timer", true));    public ForkingClusterInvoker(Directory directory) {        super(directory);    }    @Override    @SuppressWarnings({"unchecked", "rawtypes"})    public Result doInvoke(final Invocation invocation, List> invokers, LoadBalance loadbalance) throws RpcException {        try {            checkInvokers(invokers, invocation);            final List> selected;            final int forks = getUrl().getParameter(FORKS_KEY, DEFAULT_FORKS);            final int timeout = getUrl().getParameter(TIMEOUT_KEY, DEFAULT_TIMEOUT);            if (forks <= 0 || forks >= invokers.size()) {                selected = invokers;            } else {                selected = new ArrayList<>();                for (int i = 0; i < forks; i++) {                    Invoker invoker = select(loadbalance, invocation, invokers, selected);                    if (!selected.contains(invoker)) {                        //Avoid add the same invoker several times.                        selected.add(invoker);                    }                }            }            RpcContext.getContext().setInvokers((List) selected);            final AtomicInteger count = new AtomicInteger();            final BlockingQueue ref = new LinkedBlockingQueue<>();            for (final Invoker invoker : selected) {                executor.execute(new Runnable() {                    @Override                    public void run() {                        try {                            Result result = invoker.invoke(invocation);                            ref.offer(result);                        } catch (Throwable e) {                            int value = count.incrementAndGet();                            if (value >= selected.size()) {                                ref.offer(e);                            }                        }                    }                });            }            try {                Object ret = ref.poll(timeout, TimeUnit.MILLISECONDS);                if (ret instanceof Throwable) {                    Throwable e = (Throwable) ret;                    throw new RpcException(e instanceof RpcException ? ((RpcException) e).getCode() : 0, "Failed to forking invoke provider " + selected + ", but no luck to perform the invocation. Last error is: " + e.getMessage(), e.getCause() != null ? e.getCause() : e);                }                return (Result) ret;            } catch (InterruptedException e) {                throw new RpcException("Failed to forking invoke provider " + selected + ", but no luck to perform the invocation. Last error is: " + e.getMessage(), e);            }        } finally {            // clear attachments which is binding to current thread.            RpcContext.getContext().clearAttachments();        }    }}
  • ForkingClusterInvoker使用Executors.newCachedThreadPool创建了一个executor;其doInvoke从url获取forks及timeout参数,然后从invokers选出forks个数的invoker,然后放到executor请求执行invoker.invoke(invocation),把Result放到LinkedBlockingQueue,最后使用指定的timeout去poll出第一个返回结果返回,异常的话抛出RpcException

ForkingClusterInvokerTest

dubbo-2.7.3/dubbo-cluster/src/test/java/org/apache/dubbo/rpc/cluster/support/ForkingClusterInvokerTest.java

public class ForkingClusterInvokerTest {    private List> invokers = new ArrayList>();    private URL url = URL.valueOf("test://test:11/test?forks=2");    private Invoker invoker1 = mock(Invoker.class);    private Invoker invoker2 = mock(Invoker.class);    private Invoker invoker3 = mock(Invoker.class);    private RpcInvocation invocation = new RpcInvocation();    private Directory dic;    private Result result = new AppResponse();    @BeforeEach    public void setUp() throws Exception {        dic = mock(Directory.class);        given(dic.getUrl()).willReturn(url);        given(dic.list(invocation)).willReturn(invokers);        given(dic.getInterface()).willReturn(ForkingClusterInvokerTest.class);        invocation.setMethodName("method1");        invokers.add(invoker1);        invokers.add(invoker2);        invokers.add(invoker3);    }    private void resetInvokerToException() {        given(invoker1.invoke(invocation)).willThrow(new RuntimeException());        given(invoker1.getUrl()).willReturn(url);        given(invoker1.isAvailable()).willReturn(true);        given(invoker1.getInterface()).willReturn(ForkingClusterInvokerTest.class);        given(invoker2.invoke(invocation)).willThrow(new RuntimeException());        given(invoker2.getUrl()).willReturn(url);        given(invoker2.isAvailable()).willReturn(true);        given(invoker2.getInterface()).willReturn(ForkingClusterInvokerTest.class);        given(invoker3.invoke(invocation)).willThrow(new RuntimeException());        given(invoker3.getUrl()).willReturn(url);        given(invoker3.isAvailable()).willReturn(true);        given(invoker3.getInterface()).willReturn(ForkingClusterInvokerTest.class);    }    private void resetInvokerToNoException() {        given(invoker1.invoke(invocation)).willReturn(result);        given(invoker1.getUrl()).willReturn(url);        given(invoker1.isAvailable()).willReturn(true);        given(invoker1.getInterface()).willReturn(ForkingClusterInvokerTest.class);        given(invoker2.invoke(invocation)).willReturn(result);        given(invoker2.getUrl()).willReturn(url);        given(invoker2.isAvailable()).willReturn(true);        given(invoker2.getInterface()).willReturn(ForkingClusterInvokerTest.class);        given(invoker3.invoke(invocation)).willReturn(result);        given(invoker3.getUrl()).willReturn(url);        given(invoker3.isAvailable()).willReturn(true);        given(invoker3.getInterface()).willReturn(ForkingClusterInvokerTest.class);    }    @Test    public void testInvokeException() {        resetInvokerToException();        ForkingClusterInvoker invoker = new ForkingClusterInvoker(                dic);        try {            invoker.invoke(invocation);            Assertions.fail();        } catch (RpcException expected) {            Assertions.assertTrue(expected.getMessage().contains("Failed to forking invoke provider"));            assertFalse(expected.getCause() instanceof RpcException);        }    }    @Test    public void testClearRpcContext() {        resetInvokerToException();        ForkingClusterInvoker invoker = new ForkingClusterInvoker(                dic);        String attachKey = "attach";        String attachValue = "value";        RpcContext.getContext().setAttachment(attachKey, attachValue);        Map attachments = RpcContext.getContext().getAttachments();        Assertions.assertTrue(attachments != null && attachments.size() == 1, "set attachment failed!");        try {            invoker.invoke(invocation);            Assertions.fail();        } catch (RpcException expected) {            Assertions.assertTrue(expected.getMessage().contains("Failed to forking invoke provider"), "Succeeded to forking invoke provider !");            assertFalse(expected.getCause() instanceof RpcException);        }        Map afterInvoke = RpcContext.getContext().getAttachments();        Assertions.assertTrue(afterInvoke != null && afterInvoke.size() == 0, "clear attachment failed!");    }    @Test()    public void testInvokeNoException() {        resetInvokerToNoException();        ForkingClusterInvoker invoker = new ForkingClusterInvoker(                dic);        Result ret = invoker.invoke(invocation);        Assertions.assertSame(result, ret);    }}
  • ForkingClusterInvokerTest验证了testInvokeException、testClearRpcContext两个场景

小结

ForkingClusterInvoker使用Executors.newCachedThreadPool创建了一个executor;其doInvoke从url获取forks及timeout参数,然后从invokers选出forks个数的invoker,然后放到executor请求执行invoker.invoke(invocation),把Result放到LinkedBlockingQueue,最后使用指定的timeout去poll出第一个返回结果返回,异常的话抛出RpcException

上述就是小编为大家分享的dubbo中ForkingClusterInvoker的作用是什么了,如果刚好有类似的疑惑,不妨参照上述分析进行理解。如果想知道更多相关知识,欢迎关注行业资讯频道。

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