Add cluster functionality with node registration, sticky sessions, and routing

Co-authored-by: samanhappy <2755122+samanhappy@users.noreply.github.com>

tests/services/clusterService.test.ts

@@ -0,0 +1,335 @@
+/**
+ * Cluster Service Tests
+ */
+
+import {
+  isClusterEnabled,
+  getClusterMode,
+  getCurrentNodeId,
+  registerNode,
+  updateNodeHeartbeat,
+  getActiveNodes,
+  getAllNodes,
+  getServerReplicas,
+  getNodeForSession,
+  getSessionAffinity,
+  removeSessionAffinity,
+  getClusterStats,
+  shutdownClusterService,
+} from '../../src/services/clusterService';
+import { ClusterNode } from '../../src/types/index';
+
+// Mock the config module
+jest.mock('../../src/config/index.js', () => ({
+  loadSettings: jest.fn(),
+}));
+
+const { loadSettings } = require('../../src/config/index.js');
+
+describe('Cluster Service', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  afterEach(() => {
+    // Clean up cluster service to reset state
+    shutdownClusterService();
+  });
+
+  describe('Configuration', () => {
+    it('should return false when cluster is not enabled', () => {
+      loadSettings.mockReturnValue({
+        mcpServers: {},
+      });
+
+      expect(isClusterEnabled()).toBe(false);
+    });
+
+    it('should return true when cluster is enabled', () => {
+      loadSettings.mockReturnValue({
+        mcpServers: {},
+        systemConfig: {
+          cluster: {
+            enabled: true,
+            mode: 'coordinator',
+          },
+        },
+      });
+
+      expect(isClusterEnabled()).toBe(true);
+    });
+
+    it('should return standalone mode when cluster is not configured', () => {
+      loadSettings.mockReturnValue({
+        mcpServers: {},
+      });
+
+      expect(getClusterMode()).toBe('standalone');
+    });
+
+    it('should return configured mode when cluster is enabled', () => {
+      loadSettings.mockReturnValue({
+        mcpServers: {},
+        systemConfig: {
+          cluster: {
+            enabled: true,
+            mode: 'coordinator',
+          },
+        },
+      });
+
+      expect(getClusterMode()).toBe('coordinator');
+    });
+  });
+
+  describe('Node Management', () => {
+    beforeEach(() => {
+      loadSettings.mockReturnValue({
+        mcpServers: {},
+        systemConfig: {
+          cluster: {
+            enabled: true,
+            mode: 'coordinator',
+          },
+        },
+      });
+    });
+
+    it('should register a new node', () => {
+      const node: ClusterNode = {
+        id: 'node-test-1',
+        name: 'Test Node 1',
+        host: 'localhost',
+        port: 3001,
+        url: 'http://localhost:3001',
+        status: 'active',
+        lastHeartbeat: Date.now(),
+        servers: ['server1', 'server2'],
+      };
+
+      registerNode(node);
+      const nodes = getAllNodes();
+
+      // Find our node (there might be others from previous tests)
+      const registeredNode = nodes.find(n => n.id === 'node-test-1');
+      expect(registeredNode).toBeTruthy();
+      expect(registeredNode?.name).toBe('Test Node 1');
+      expect(registeredNode?.servers).toEqual(['server1', 'server2']);
+    });
+
+    it('should update node heartbeat', () => {
+      const node: ClusterNode = {
+        id: 'node-test-2',
+        name: 'Test Node 2',
+        host: 'localhost',
+        port: 3001,
+        url: 'http://localhost:3001',
+        status: 'active',
+        lastHeartbeat: Date.now() - 10000,
+        servers: ['server1'],
+      };
+
+      registerNode(node);
+      const beforeHeartbeat = getAllNodes().find(n => n.id === 'node-test-2')?.lastHeartbeat || 0;
+
+      // Wait a bit to ensure timestamp changes
+      setTimeout(() => {
+        updateNodeHeartbeat('node-test-2', ['server1', 'server2']);
+        const updatedNode = getAllNodes().find(n => n.id === 'node-test-2');
+        const afterHeartbeat = updatedNode?.lastHeartbeat || 0;
+
+        expect(afterHeartbeat).toBeGreaterThan(beforeHeartbeat);
+        expect(updatedNode?.servers).toEqual(['server1', 'server2']);
+      }, 10);
+    });
+
+    it('should get active nodes only', () => {
+      const node1: ClusterNode = {
+        id: 'node-active-1',
+        name: 'Active Node',
+        host: 'localhost',
+        port: 3001,
+        url: 'http://localhost:3001',
+        status: 'active',
+        lastHeartbeat: Date.now(),
+        servers: ['server1'],
+      };
+
+      registerNode(node1);
+
+      const activeNodes = getActiveNodes();
+      const activeNode = activeNodes.find(n => n.id === 'node-active-1');
+      expect(activeNode).toBeTruthy();
+      expect(activeNode?.status).toBe('active');
+    });
+  });
+
+  describe('Server Replicas', () => {
+    beforeEach(() => {
+      loadSettings.mockReturnValue({
+        mcpServers: {},
+        systemConfig: {
+          cluster: {
+            enabled: true,
+            mode: 'coordinator',
+          },
+        },
+      });
+    });
+
+    it('should track server replicas across nodes', () => {
+      const node1: ClusterNode = {
+        id: 'node-replica-1',
+        name: 'Node 1',
+        host: 'localhost',
+        port: 3001,
+        url: 'http://localhost:3001',
+        status: 'active',
+        lastHeartbeat: Date.now(),
+        servers: ['test-server-1', 'test-server-2'],
+      };
+
+      const node2: ClusterNode = {
+        id: 'node-replica-2',
+        name: 'Node 2',
+        host: 'localhost',
+        port: 3002,
+        url: 'http://localhost:3002',
+        status: 'active',
+        lastHeartbeat: Date.now(),
+        servers: ['test-server-1', 'test-server-3'],
+      };
+
+      registerNode(node1);
+      registerNode(node2);
+
+      const server1Replicas = getServerReplicas('test-server-1');
+      expect(server1Replicas.length).toBeGreaterThanOrEqual(2);
+      expect(server1Replicas.map(r => r.nodeId)).toContain('node-replica-1');
+      expect(server1Replicas.map(r => r.nodeId)).toContain('node-replica-2');
+    });
+  });
+
+  describe('Session Affinity', () => {
+    beforeEach(() => {
+      loadSettings.mockReturnValue({
+        mcpServers: {},
+        systemConfig: {
+          cluster: {
+            enabled: true,
+            mode: 'coordinator',
+            stickySession: {
+              enabled: true,
+              strategy: 'consistent-hash',
+            },
+          },
+        },
+      });
+    });
+
+    it('should maintain session affinity with consistent hash', () => {
+      const node1: ClusterNode = {
+        id: 'node-affinity-1',
+        name: 'Node 1',
+        host: 'localhost',
+        port: 3001,
+        url: 'http://localhost:3001',
+        status: 'active',
+        lastHeartbeat: Date.now(),
+        servers: ['server1'],
+      };
+
+      registerNode(node1);
+
+      const sessionId = 'test-session-consistent-hash';
+      const firstNode = getNodeForSession(sessionId);
+      const secondNode = getNodeForSession(sessionId);
+
+      expect(firstNode).toBeTruthy();
+      expect(secondNode).toBeTruthy();
+      expect(firstNode?.id).toBe(secondNode?.id);
+    });
+
+    it('should create and retrieve session affinity', () => {
+      const node1: ClusterNode = {
+        id: 'node-affinity-2',
+        name: 'Node 1',
+        host: 'localhost',
+        port: 3001,
+        url: 'http://localhost:3001',
+        status: 'active',
+        lastHeartbeat: Date.now(),
+        servers: ['server1'],
+      };
+
+      registerNode(node1);
+
+      const sessionId = 'test-session-retrieve';
+      const selectedNode = getNodeForSession(sessionId);
+      
+      const affinity = getSessionAffinity(sessionId);
+      expect(affinity).toBeTruthy();
+      expect(affinity?.sessionId).toBe(sessionId);
+      expect(affinity?.nodeId).toBe(selectedNode?.id);
+    });
+
+    it('should remove session affinity', () => {
+      const node1: ClusterNode = {
+        id: 'node-affinity-3',
+        name: 'Node 1',
+        host: 'localhost',
+        port: 3001,
+        url: 'http://localhost:3001',
+        status: 'active',
+        lastHeartbeat: Date.now(),
+        servers: ['server1'],
+      };
+
+      registerNode(node1);
+
+      const sessionId = 'test-session-remove';
+      getNodeForSession(sessionId);
+      
+      let affinity = getSessionAffinity(sessionId);
+      expect(affinity).toBeTruthy();
+
+      removeSessionAffinity(sessionId);
+      affinity = getSessionAffinity(sessionId);
+      expect(affinity).toBeNull();
+    });
+  });
+
+  describe('Cluster Statistics', () => {
+    beforeEach(() => {
+      loadSettings.mockReturnValue({
+        mcpServers: {},
+        systemConfig: {
+          cluster: {
+            enabled: true,
+            mode: 'coordinator',
+          },
+        },
+      });
+    });
+
+    it('should return cluster statistics', () => {
+      const node1: ClusterNode = {
+        id: 'node-stats-1',
+        name: 'Node 1',
+        host: 'localhost',
+        port: 3001,
+        url: 'http://localhost:3001',
+        status: 'active',
+        lastHeartbeat: Date.now(),
+        servers: ['unique-server-1', 'unique-server-2'],
+      };
+
+      registerNode(node1);
+
+      const stats = getClusterStats();
+      expect(stats.nodes).toBeGreaterThanOrEqual(1);
+      expect(stats.activeNodes).toBeGreaterThanOrEqual(1);
+      expect(stats.servers).toBeGreaterThanOrEqual(2);
+    });
+  });
+});