[Dubbo- support tag router feature] Add a new Router implement -- TagRouter

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/router/tag/TagRouter.java

@@ -0,0 +1,109 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.dubbo.rpc.cluster.router.tag;
+
+
+import org.apache.dubbo.common.Constants;
+import org.apache.dubbo.common.URL;
+import org.apache.dubbo.common.logger.Logger;
+import org.apache.dubbo.common.logger.LoggerFactory;
+import org.apache.dubbo.common.utils.StringUtils;
+import org.apache.dubbo.rpc.Invocation;
+import org.apache.dubbo.rpc.Invoker;
+import org.apache.dubbo.rpc.RpcContext;
+import org.apache.dubbo.rpc.RpcException;
+import org.apache.dubbo.rpc.cluster.Router;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * TagRouter
+ */
+public class TagRouter implements Router, Comparable<Router> {
+
+    private static final Logger logger = LoggerFactory.getLogger(TagRouter.class);
+
+    private final int priority;
+    private final URL url;
+
+    public static final URL ROUTER_URL = new URL("tag", Constants.ANYHOST_VALUE, 0, Constants.ANY_VALUE).addParameters(Constants.RUNTIME_KEY, "true");
+
+    public TagRouter(URL url) {
+        this.url = url;
+        this.priority = url.getParameter(Constants.PRIORITY_KEY, 0);
+    }
+
+    public TagRouter() {
+        this.url = ROUTER_URL;
+        this.priority = url.getParameter(Constants.PRIORITY_KEY, 0);
+    }
+
+    @Override
+    public URL getUrl() {
+        return url;
+    }
+
+    @Override
+    public <T> List<Invoker<T>> route(List<Invoker<T>> invokers, URL url, Invocation invocation) throws RpcException {
+        // filter
+        List<Invoker<T>> result = new ArrayList<>();
+        try {
+            // Dynamic param
+            String tag = RpcContext.getContext().getAttachment(Constants.REQUEST_TAG_KEY);
+            // Tag request
+            if (!StringUtils.isEmpty(tag)) {
+                // Select tag invokers first
+                for (Invoker<T> invoker : invokers) {
+                    if (tag.equals(invoker.getUrl().getParameter(Constants.TAG_KEY))) {
+                        result.add(invoker);
+                    }
+                }
+                // If no invoker be selected, downgrade to normal invokers
+                if (result.isEmpty()) {
+                    for (Invoker<T> invoker : invokers) {
+                        if (StringUtils.isEmpty(invoker.getUrl().getParameter(Constants.TAG_KEY))) {
+                            result.add(invoker);
+                        }
+                    }
+                }
+            // Normal request
+            } else {
+                for (Invoker<T> invoker : invokers) {
+                    // Can't access tag invoker,only normal invoker should be selected
+                    if (StringUtils.isEmpty(invoker.getUrl().getParameter(Constants.TAG_KEY))) {
+                        result.add(invoker);
+                    }
+                }
+            }
+            return result;
+        } catch (Exception e) {
+            logger.error("Route by tag error,return all invokers.", e);
+        }
+        // Downgrade to all invokers
+        return invokers;
+    }
+
+    @Override
+    public int compareTo(Router o) {
+        if (o == null || o.getClass() != TagRouter.class) {
+            return 1;
+        }
+        TagRouter c = (TagRouter) o;
+        return this.priority == c.priority ? url.toFullString().compareTo(c.url.toFullString()) : (this.priority > c.priority ? 1 : -1);
+    }
+}

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/router/tag/TagRouterFactory.java

@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.dubbo.rpc.cluster.router.tag;
+
+
+import org.apache.dubbo.common.URL;
+import org.apache.dubbo.rpc.cluster.Router;
+import org.apache.dubbo.rpc.cluster.RouterFactory;
+
+public class TagRouterFactory implements RouterFactory {
+
+    public static final String NAME = "tag";
+
+    @Override
+    public Router getRouter(URL url) {
+        return new TagRouter(url);
+    }
+}

dubbo-cluster/src/main/resources/META-INF/dubbo/internal/org.apache.dubbo.rpc.cluster.RouterFactory

@@ -1,3 +1,4 @@
 file=org.apache.dubbo.rpc.cluster.router.file.FileRouterFactory
 script=org.apache.dubbo.rpc.cluster.router.script.ScriptRouterFactory
-condition=org.apache.dubbo.rpc.cluster.router.condition.ConditionRouterFactory
+condition=org.apache.dubbo.rpc.cluster.router.condition.ConditionRouterFactory
+tag=org.apache.dubbo.rpc.cluster.router.tag.TagRouterFactory

dubbo-cluster/src/test/java/org/apache/dubbo/rpc/cluster/router/tag/TagRouterTest.java

@@ -0,0 +1,169 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.dubbo.rpc.cluster.router.tag;
+
+import org.apache.dubbo.common.Constants;
+import org.apache.dubbo.common.URL;
+import org.apache.dubbo.common.extension.ExtensionLoader;
+import org.apache.dubbo.common.utils.NetUtils;
+import org.apache.dubbo.rpc.Invoker;
+import org.apache.dubbo.rpc.RpcContext;
+import org.apache.dubbo.rpc.RpcInvocation;
+import org.apache.dubbo.rpc.cluster.Router;
+import org.apache.dubbo.rpc.cluster.RouterFactory;
+import org.apache.dubbo.rpc.cluster.router.MockInvoker;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class TagRouterTest {
+
+    private URL tagUrl = new URL("tag"
+            , Constants.ANYHOST_VALUE, 0
+            , Constants.ANY_VALUE)
+            .addParameters(
+                    Constants.RUNTIME_KEY, "true"
+            );
+
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+    }
+
+    @Before
+    public void setUp() throws Exception {
+    }
+
+    @Test
+    public void testRoute_matchTag() {
+
+        RpcContext.getContext().setAttachment(Constants.REQUEST_TAG_KEY, "red");
+
+        List<Invoker<String>> invokers = new ArrayList<>();
+        Invoker<String> redInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.1:20880/com.foo.BarService?tag=red"));
+        Invoker<String> yellowInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.2:20880/com.foo.BarService?tag=yellow"));
+        Invoker<String> blueInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.3:20880/com.foo.BarService?tag=blue"));
+        Invoker<String> defaultInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.4:20880/com.foo.BarService"));
+
+        invokers.add(redInvoker);
+        invokers.add(yellowInvoker);
+        invokers.add(blueInvoker);
+        invokers.add(defaultInvoker);
+
+        Router tagRouter = new TagRouterFactory().getRouter(tagUrl);
+        List<Invoker<String>> filteredInvokers = tagRouter.route(invokers, URL.valueOf("consumer://" + NetUtils.getLocalHost() + "/com.foo.BarService"), new RpcInvocation());
+        Assert.assertTrue(filteredInvokers.contains(redInvoker));
+        Assert.assertFalse(filteredInvokers.contains(yellowInvoker));
+        Assert.assertFalse(filteredInvokers.contains(blueInvoker));
+        Assert.assertFalse(filteredInvokers.contains(defaultInvoker));
+    }
+
+    @Test
+    public void testRoute_matchDefault() {
+
+        RpcContext.getContext().setAttachment(Constants.REQUEST_TAG_KEY, "");
+
+        List<Invoker<String>> invokers = new ArrayList<>();
+        Invoker<String> redInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.1:20880/com.foo.BarService?tag=red"));
+        Invoker<String> yellowInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.2:20880/com.foo.BarService?tag=yellow"));
+        Invoker<String> blueInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.3:20880/com.foo.BarService?tag=blue"));
+        Invoker<String> defaultInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.4:20880/com.foo.BarService"));
+
+        invokers.add(redInvoker);
+        invokers.add(yellowInvoker);
+        invokers.add(blueInvoker);
+        invokers.add(defaultInvoker);
+
+        Router tagRouter = new TagRouterFactory().getRouter(tagUrl);
+        List<Invoker<String>> filteredInvokers = tagRouter.route(invokers, URL.valueOf("consumer://" + NetUtils.getLocalHost() + "/com.foo.BarService"), new RpcInvocation());
+        Assert.assertTrue(filteredInvokers.contains(defaultInvoker));
+        Assert.assertFalse(filteredInvokers.contains(yellowInvoker));
+        Assert.assertFalse(filteredInvokers.contains(blueInvoker));
+        Assert.assertFalse(filteredInvokers.contains(redInvoker));
+    }
+
+    @Test
+    public void testRoute_requestWithTag_shouldDowngrade() {
+
+        RpcContext.getContext().setAttachment(Constants.REQUEST_TAG_KEY, "black");
+
+        List<Invoker<String>> invokers = new ArrayList<>();
+        Invoker<String> redInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.1:20880/com.foo.BarService?tag=red"));
+        Invoker<String> yellowInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.2:20880/com.foo.BarService?tag=yellow"));
+        Invoker<String> blueInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.3:20880/com.foo.BarService?tag=blue"));
+        Invoker<String> defaultInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.4:20880/com.foo.BarService"));
+
+        invokers.add(redInvoker);
+        invokers.add(yellowInvoker);
+        invokers.add(blueInvoker);
+        invokers.add(defaultInvoker);
+
+        Router tagRouter = new TagRouterFactory().getRouter(tagUrl);
+        List<Invoker<String>> filteredInvokers = tagRouter.route(invokers, URL.valueOf("consumer://" + NetUtils.getLocalHost() + "/com.foo.BarService"), new RpcInvocation());
+        Assert.assertTrue(filteredInvokers.contains(defaultInvoker));
+        Assert.assertFalse(filteredInvokers.contains(yellowInvoker));
+        Assert.assertFalse(filteredInvokers.contains(blueInvoker));
+        Assert.assertFalse(filteredInvokers.contains(redInvoker));
+    }
+
+    @Test
+    public void testRoute_requestWithoutTag_shouldNotDowngrade() {
+
+        RpcContext.getContext().setAttachment(Constants.REQUEST_TAG_KEY, "");
+
+        List<Invoker<String>> invokers = new ArrayList<>();
+        Invoker<String> redInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.1:20880/com.foo.BarService?tag=red"));
+        Invoker<String> yellowInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.2:20880/com.foo.BarService?tag=yellow"));
+        Invoker<String> blueInvoker = new MockInvoker<>(URL.valueOf(
+                "dubbo://10.20.3.3:20880/com.foo.BarService?tag=blue"));
+
+        invokers.add(redInvoker);
+        invokers.add(yellowInvoker);
+        invokers.add(blueInvoker);
+
+        Router tagRouter = new TagRouterFactory().getRouter(tagUrl);
+        List<Invoker<String>> filteredInvokers = tagRouter.route(invokers, URL.valueOf("consumer://" + NetUtils.getLocalHost() + "/com.foo.BarService"), new RpcInvocation());
+        Assert.assertEquals(0, filteredInvokers.size());
+    }
+
+    @Test
+    public void testRoute_createBySpi() {
+        URL zkProvider = URL.valueOf("zookeeper://10.20.3.1:20880/com.foo.BarService?router=tag");
+        String parameter = zkProvider.getParameter(Constants.ROUTER_KEY);
+        RouterFactory routerFactory = ExtensionLoader.getExtensionLoader(RouterFactory.class).getExtension(parameter);
+        Router tagRouter = routerFactory.getRouter(zkProvider);
+        Assert.assertTrue(tagRouter instanceof TagRouter);
+    }
+
+}

dubbo-common/src/main/java/org/apache/dubbo/common/Constants.java

@@ -641,6 +641,10 @@ public class Constants {
 
     public static final String MULTICAST = "multicast";
 
+    public static final String TAG_KEY = "tag";
+
+    public static final String REQUEST_TAG_KEY = "request.tag";
+
     /*
      * private Constants(){ }
      */

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractInterfaceConfig.java

@@ -522,5 +522,4 @@ public String getScope() {
     public void setScope(String scope) {
         this.scope = scope;
     }
-
 }

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractReferenceConfig.java

@@ -197,5 +197,4 @@ public void setGroup(String group) {
         checkKey("group", group);
         this.group = group;
     }
-
 }

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/AbstractServiceConfig.java

@@ -73,6 +73,9 @@ public abstract class AbstractServiceConfig extends AbstractInterfaceConfig {
     // serialization
     private String serialization;
 
+    // provider tag
+    protected String tag;
+
     public String getVersion() {
         return version;
     }
@@ -240,4 +243,11 @@ public void setSerialization(String serialization) {
         this.serialization = serialization;
     }
 
+    public String getTag() {
+        return tag;
+    }
+
+    public void setTag(String tag) {
+        this.tag = tag;
+    }
 }

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/annotation/Service.java

@@ -263,4 +263,9 @@
      * Registry spring bean name
      */
     String[] registry() default {};
+
+    /**
+     * Service tag name
+     */
+    String tag() default "";
 }