java高级编程期末大作业-设计nosql数据库.zip

package com.nosql.db.cluster; import com.nosql.common.protocol.DBResponse; import com.nosql.db.core.storage.LSMStore; import com.nosql.db.core.wal.WALEntry; import com.nosql.db.network.DBCommand; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.net.Socket; import java.util.*; import java.util.concurrent.*; import java.util.stream.Collectors; public class ClusterManager { private static final int ELECTION_TIMEOUT = 3000; private static final int HEARTBEAT_INTERVAL = 500; private Node leader; private final String nodeId; private final List<Node> nodes = new CopyOnWriteArrayList<>(); private final LSMStore storage; private final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(2); public ClusterManager(String nodeId, LSMStore storage) { this.nodeId = nodeId; this.storage = storage; } // 启动集群服务 public void startCluster() { scheduler.scheduleAtFixedRate(this::checkLeaderStatus, HEARTBEAT_INTERVAL, HEARTBEAT_INTERVAL, TimeUnit.MILLISECONDS); scheduler.scheduleAtFixedRate(this::cleanDeadNodes, 5, 5, TimeUnit.SECONDS); } // 处理写请求 public void handleWrite(DBCommand command) throws IOException { // 添加幂等性检查 if (command instanceof DBCommand.putCommand) { String docId = ((DBCommand.putCommand)command).getData().get("id").toString(); if (storage.get(docId) != null) { return; // 已存在则不处理 } } else if (command instanceof DBCommand.DeleteCommand) { DBCommand.DeleteCommand delCmd = (DBCommand.DeleteCommand) command; if (storage.get(delCmd.getId()) == null) { return; // 文档不存在时跳过 } } // 新增：所有节点都要处理本地存储 processLocally(command); if (isLeader()) { storage.getWal().writeEntry(convertToWALEntry(command)); replicateToNodes(command); } else { forwardToLeader(command); } } // 选举核心逻辑 private synchronized void electLeader() { Node newLeader = nodes.stream() .filter(Node::isAlive) .min(Comparator.comparing(Node::getId)) .orElse(null); if (newLeader != null && newLeader.getId().equals(nodeId)) { becomeLeader(); } else if (newLeader != null) { this.leader = newLeader; } } // 成为Leader后的初始化 private void becomeLeader() { leader = new Node(nodeId, "localhost", 8080, Node.Role.LEADER); System.out.println("["+nodeId+"] 开始担任Leader，当前节点列表: " + nodes.stream().map(Node::getId).collect(Collectors.joining(","))); nodes.removeIf(n -> n.getId().equals(nodeId)); nodes.add(leader); } // 数据复制到其他节点 private void replicateToNodes(DBCommand command) { int successCount = 0; for (Node node : nodes) { if (!node.getId().equals(nodeId) && sendReplication(node, command)) { successCount++; } } if (successCount >= nodes.size() / 2) { System.out.println("["+nodeId+"] 数据复制结果: 成功" + successCount + "/总" + nodes.size()); } } // 发送复制请求（简化实现） private boolean sendReplication(Node node, DBCommand command) { try (Socket socket = new Socket(node.getHost(), node.getPort())) { ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream()); out.writeObject(command); return true; } catch (IOException e) { System.err.println("复制到节点 " + node.getId() + " 失败"); return false; } } // 其他辅助方法 private boolean isLeader() { return leader != null && leader.getId().equals(nodeId); } private void checkLeaderStatus() { if (leader == null || !leader.isAlive()) { electLeader(); } } private void cleanDeadNodes() { nodes.removeIf(node -> !node.isAlive()); } // 转换命令到WAL日志条目 private WALEntry convertToWALEntry(DBCommand command) { if (command instanceof DBCommand.putCommand) { DBCommand.putCommand putCmd = (DBCommand.putCommand) command; // 直接从命令数据中获取服务端生成的ID String docId = (String) putCmd.getData().get("id"); return new WALEntry( WALEntry.Operation.PUT, docId, putCmd.getData() ); } else if (command instanceof DBCommand.DeleteCommand) { DBCommand.DeleteCommand delCmd = (DBCommand.DeleteCommand) command; return new WALEntry(WALEntry.Operation.DELETE, delCmd.getId()); } throw new IllegalArgumentException("不支持的命令类型: " + command.getType()); } // 转发请求到Leader节点 private void forwardToLeader(DBCommand command) throws IOException { if (leader == null) { throw new IOException("当前无可用Leader"); } try (Socket socket = new Socket(leader.getHost(), leader.getPort())) { ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream()); ObjectInputStream in = new ObjectInputStream(socket.getInputStream()); out.writeObject(command); Object response = in.readObject(); if (response instanceof Exception) { throw new IOException("Leader处理失败", (Exception) response); } } catch (ClassNotFoundException e) { throw new IOException("响应解析失败", e); } } // 新增集群加入方法 // 加入集群的简化实现 public void joinCluster(List<Node> seedNodes) { // 基础校验 if (seedNodes == null || seedNodes.isEmpty()) { System.err.println("无效的种子节点列表"); return; } // 添加存活节点到集群 nodes.addAll(seedNodes.stream() .filter(Node::isAlive) .collect(Collectors.toList())); // 如果当前没有Leader，立即触发选举 if (leader == null) { electLeader(); } System.out.println("["+nodeId+"] 成功加入集群，当前节点数: " + nodes.size()); } // 新增本地处理方法（添加在ClusterManager类中） private void processLocally(DBCommand command) throws IOException { if (command instanceof DBCommand.putCommand) { DBCommand.putCommand putCmd = (DBCommand.putCommand) command; storage.put(putCmd.getCollection(), putCmd.getData()); } else if (command instanceof DBCommand.DeleteCommand) { DBCommand.DeleteCommand delCmd = (DBCommand.DeleteCommand) command; storage.delete(delCmd.getCollection(), delCmd.getId()); } else if (command instanceof DBCommand.CreateCollectionCommand) { DBCommand.CreateCollectionCommand createCmd = (DBCommand.CreateCollectionCommand) command; storage.createCollection(createCmd.getCollection()); } } }