feat/Examples about priority-based semi-deterministic leader election. (

sofastack#417)

* feat/Examples about priority-based semi-deterministic leader election for users.

* feat/fix some codes conflicts.

* feat/fix typo.

* feat/fix typo.

jraft-example/src/main/java/com/alipay/sofa/jraft/example/election/ElectionBootstrap.java

@@ -16,6 +16,8 @@
  */
 package com.alipay.sofa.jraft.example.election;
 
+import com.alipay.sofa.jraft.entity.PeerId;
+
 /**
  *
  * @author jiachun.fjc
@@ -46,8 +48,13 @@ public static void main(final String[] args) {
         final ElectionNode node = new ElectionNode();
         node.addLeaderStateListener(new LeaderStateListener() {
 
+            PeerId serverId = node.getNode().getLeaderId();
+            String ip       = serverId.getIp();
+            int    port     = serverId.getPort();
+
             @Override
             public void onLeaderStart(long leaderTerm) {
+                System.out.println("[ElectionBootstrap] Leader's ip is: " + ip + ", port: " + port);
                 System.out.println("[ElectionBootstrap] Leader start on term: " + leaderTerm);
             }
 

jraft-example/src/main/java/com/alipay/sofa/jraft/example/election/ElectionNode.java

@@ -54,7 +54,7 @@ public class ElectionNode implements Lifecycle<ElectionNodeOptions> {
     @Override
     public boolean init(final ElectionNodeOptions opts) {
         if (this.started) {
-            LOG.info("[ElectionNode: {}] already started.");
+            LOG.info("[ElectionNode: {}] already started.", opts.getServerAddress());
             return true;
         }
         // node options
@@ -112,7 +112,7 @@ public void shutdown() {
             }
         }
         this.started = false;
-        LOG.info("[RegionEngine] shutdown successfully: {}.", this);
+        LOG.info("[ElectionNode] shutdown successfully: {}.", this);
     }
 
     public Node getNode() {

jraft-example/src/main/java/com/alipay/sofa/jraft/example/priorityelection/LeaderStateListener.java

@@ -0,0 +1,33 @@
+/*
+ * 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 com.alipay.sofa.jraft.example.priorityelection;
+
+/**
+ * @author zongtanghu
+ */
+public interface LeaderStateListener {
+
+    /**
+     * Called when current node becomes leader
+     */
+    void onLeaderStart(final long leaderTerm);
+
+    /**
+     * Called when current node loses leadership.
+     */
+    void onLeaderStop(final long leaderTerm);
+}

jraft-example/src/main/java/com/alipay/sofa/jraft/example/priorityelection/PriorityElectionBootstrap.java

@@ -0,0 +1,76 @@
+/*
+ * 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 com.alipay.sofa.jraft.example.priorityelection;
+
+import com.alipay.sofa.jraft.entity.PeerId;
+
+/**
+ *
+ * @author zongtanghu
+ */
+public class PriorityElectionBootstrap {
+
+    // Start elections by 3 instance. Note that if multiple instances are started on the same machine,
+    // the first parameter `dataPath` should not be the same,
+    // the second parameter `groupId` should be set the same value, eg: election_test,
+    // the third parameter `serverId` should be set ip and port with priority value, eg: 127.0.0.1:8081::100, and middle postion can be empty string,
+    // the fourth parameter `initialConfStr` should be set the all of endpoints in raft cluster, eg : 127.0.0.1:8081::100,127.0.0.1:8082::40,127.0.0.1:8083::40.
+
+    public static void main(final String[] args) {
+        if (args.length < 4) {
+            System.out
+                .println("Useage : java com.alipay.sofa.jraft.example.priorityelection.PriorityElectionBootstrap {dataPath} {groupId} {serverId} {initConf}");
+            System.out
+                .println("Example: java com.alipay.sofa.jraft.example.priorityelection.PriorityElectionBootstrap /tmp/server1 election_test 127.0.0.1:8081::100 127.0.0.1:8081::100,127.0.0.1:8082::40,127.0.0.1:8083::40");
+            System.exit(1);
+        }
+        final String dataPath = args[0];
+        final String groupId = args[1];
+        final String serverIdStr = args[2];
+        final String initialConfStr = args[3];
+
+        final PriorityElectionNodeOptions priorityElectionOpts = new PriorityElectionNodeOptions();
+        priorityElectionOpts.setDataPath(dataPath);
+        priorityElectionOpts.setGroupId(groupId);
+        priorityElectionOpts.setServerAddress(serverIdStr);
+        priorityElectionOpts.setInitialServerAddressList(initialConfStr);
+
+        final PriorityElectionNode node = new PriorityElectionNode();
+        node.addLeaderStateListener(new LeaderStateListener() {
+
+            @Override
+            public void onLeaderStart(long leaderTerm) {
+
+                PeerId serverId = node.getNode().getLeaderId();
+                int priority = serverId.getPriority();
+                String ip = serverId.getIp();
+                int port = serverId.getPort();
+
+                System.out.println("[PriorityElectionBootstrap] Leader's ip is: " + ip + ", port: " + port
+                                   + ", priority: " + priority);
+                System.out.println("[PriorityElectionBootstrap] Leader start on term: " + leaderTerm);
+            }
+
+            @Override
+            public void onLeaderStop(long leaderTerm) {
+                System.out.println("[PriorityElectionBootstrap] Leader stop on term: " + leaderTerm);
+            }
+        });
+        node.init(priorityElectionOpts);
+    }
+
+}

jraft-example/src/main/java/com/alipay/sofa/jraft/example/priorityelection/PriorityElectionNode.java

@@ -0,0 +1,141 @@
+/*
+ * 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 com.alipay.sofa.jraft.example.priorityelection;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import org.apache.commons.io.FileUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.alipay.sofa.jraft.Lifecycle;
+import com.alipay.sofa.jraft.Node;
+import com.alipay.sofa.jraft.RaftGroupService;
+import com.alipay.sofa.jraft.conf.Configuration;
+import com.alipay.sofa.jraft.entity.PeerId;
+import com.alipay.sofa.jraft.option.NodeOptions;
+import com.alipay.sofa.jraft.rpc.RaftRpcServerFactory;
+import com.alipay.sofa.jraft.rpc.RpcServer;
+import com.alipay.sofa.jraft.util.internal.ThrowUtil;
+
+/**
+ * @author zongtanghu
+ */
+public class PriorityElectionNode implements Lifecycle<PriorityElectionNodeOptions> {
+
+    private static final Logger              LOG       = LoggerFactory.getLogger(PriorityElectionNode.class);
+
+    private final List<LeaderStateListener>  listeners = new CopyOnWriteArrayList<>();
+    private RaftGroupService                 raftGroupService;
+    private Node                             node;
+    private PriorityElectionOnlyStateMachine fsm;
+
+    private boolean                          started;
+
+    @Override
+    public boolean init(final PriorityElectionNodeOptions opts) {
+        if (this.started) {
+            LOG.info("[PriorityElectionNode: {}] already started.", opts.getServerAddress());
+            return true;
+        }
+        // node options
+        NodeOptions nodeOpts = opts.getNodeOptions();
+        if (nodeOpts == null) {
+            nodeOpts = new NodeOptions();
+        }
+        this.fsm = new PriorityElectionOnlyStateMachine(this.listeners);
+        // Set the initial PriorityElectionOnlyStateMachine
+        nodeOpts.setFsm(this.fsm);
+        final Configuration initialConf = new Configuration();
+        if (!initialConf.parse(opts.getInitialServerAddressList())) {
+            throw new IllegalArgumentException("Fail to parse initConf: " + opts.getInitialServerAddressList());
+        }
+        // Set the initial cluster configuration
+        nodeOpts.setInitialConf(initialConf);
+        final String dataPath = opts.getDataPath();
+        try {
+            FileUtils.forceMkdir(new File(dataPath));
+        } catch (final IOException e) {
+            LOG.error("Fail to make dir for dataPath {}.", dataPath);
+            return false;
+        }
+        // Set the data path
+        // Log, required
+        nodeOpts.setLogUri(Paths.get(dataPath, "log").toString());
+        // Metadata, required
+        nodeOpts.setRaftMetaUri(Paths.get(dataPath, "meta").toString());
+        // nodeOpts.setSnapshotUri(Paths.get(dataPath, "snapshot").toString());
+
+        final String groupId = opts.getGroupId();
+        final PeerId serverId = new PeerId();
+        if (!serverId.parse(opts.getServerAddress())) {
+            throw new IllegalArgumentException("Fail to parse serverId: " + opts.getServerAddress());
+        }
+        // Set priority value, required
+        nodeOpts.setElectionPriority(serverId.getPriority());
+
+        final RpcServer rpcServer = RaftRpcServerFactory.createRaftRpcServer(serverId.getEndpoint());
+        this.raftGroupService = new RaftGroupService(groupId, serverId, nodeOpts, rpcServer);
+        this.node = this.raftGroupService.start();
+        if (this.node != null) {
+            this.started = true;
+        }
+        return this.started;
+    }
+
+    @Override
+    public void shutdown() {
+        if (!this.started) {
+            return;
+        }
+        if (this.raftGroupService != null) {
+            this.raftGroupService.shutdown();
+            try {
+                this.raftGroupService.join();
+            } catch (final InterruptedException e) {
+                ThrowUtil.throwException(e);
+            }
+        }
+        this.started = false;
+        LOG.info("[ElectionNode] shutdown successfully: {}.", this);
+    }
+
+    public Node getNode() {
+        return node;
+    }
+
+    public PriorityElectionOnlyStateMachine getFsm() {
+        return fsm;
+    }
+
+    public boolean isStarted() {
+        return started;
+    }
+
+    public boolean isLeader() {
+        return this.fsm.isLeader();
+    }
+
+    public void addLeaderStateListener(final LeaderStateListener listener) {
+        this.listeners.add(listener);
+    }
+
+}

jraft-example/src/main/java/com/alipay/sofa/jraft/example/priorityelection/PriorityElectionNodeOptions.java

@@ -0,0 +1,82 @@
+/*
+ * 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 com.alipay.sofa.jraft.example.priorityelection;
+
+import com.alipay.sofa.jraft.option.NodeOptions;
+
+/**
+ * @author zongtanghu
+ */
+public class PriorityElectionNodeOptions {
+
+    private String      dataPath;
+    // raft group id
+    private String      groupId;
+    // ip:port::priority
+    private String      serverAddress;
+    // ip:port::priority,ip:port::priority,ip:port::priority
+    private String      initialServerAddressList;
+    // raft node options
+    private NodeOptions nodeOptions;
+
+    public String getDataPath() {
+        return dataPath;
+    }
+
+    public void setDataPath(String dataPath) {
+        this.dataPath = dataPath;
+    }
+
+    public String getGroupId() {
+        return groupId;
+    }
+
+    public void setGroupId(String groupId) {
+        this.groupId = groupId;
+    }
+
+    public String getServerAddress() {
+        return serverAddress;
+    }
+
+    public void setServerAddress(String serverAddress) {
+        this.serverAddress = serverAddress;
+    }
+
+    public String getInitialServerAddressList() {
+        return initialServerAddressList;
+    }
+
+    public void setInitialServerAddressList(String initialServerAddressList) {
+        this.initialServerAddressList = initialServerAddressList;
+    }
+
+    public NodeOptions getNodeOptions() {
+        return nodeOptions;
+    }
+
+    public void setNodeOptions(NodeOptions nodeOptions) {
+        this.nodeOptions = nodeOptions;
+    }
+
+    @Override
+    public String toString() {
+        return "PriorityElectionNodeOptions{" + "dataPath='" + dataPath + '\'' + ", groupId='" + groupId + '\''
+               + ", serverAddress='" + serverAddress + '\'' + ", initialServerAddressList='" + initialServerAddressList
+               + '\'' + ", nodeOptions=" + nodeOptions + '}';
+    }
+}