Production State Architecture

1// Domain-based state structure
2interface AppState {
3  // User Management Domain
4  userManagement: {
5    users: UsersState;
6    authentication: AuthState;
7    permissions: PermissionsState;
8  };
9
10  // Content Management Domain
11  contentManagement: {
12    articles: ArticlesState;
13    media: MediaState;
14    comments: CommentsState;
15  };
16
17  // Analytics Domain
18  analytics: {
19    events: EventsState;
20    metrics: MetricsState;
21    reports: ReportsState;
22  };
23
24  // Infrastructure
25  infrastructure: {
26    cache: CacheState;
27    notifications: NotificationsState;
28    errors: ErrorState;
29  };
30}
31
32// Domain-specific store modules
33const createUserManagementStore = () => ({
34  users: usersSlice.reducer,
35  authentication: authSlice.reducer,
36  permissions: permissionsSlice.reducer
37});
38
39const createContentManagementStore = () => ({
40  articles: articlesSlice.reducer,
41  media: mediaSlice.reducer,
42  comments: commentsSlice.reducer
43});

1// Presentation Layer
2interface PresentationLayer {
3  ui: UIState;
4  routing: RoutingState;
5  theming: ThemingState;
6}
7
8// Business Logic Layer
9interface BusinessLayer {
10  workflows: WorkflowsState;
11  validation: ValidationState;
12  calculations: CalculationsState;
13}
14
15// Data Access Layer
16interface DataLayer {
17  entities: EntitiesState;
18  cache: CacheState;
19  sync: SyncState;
20}
21
22// Infrastructure Layer
23interface InfrastructureLayer {
24  api: ApiState;
25  monitoring: MonitoringState;
26  configuration: ConfigState;
27}

1// Host application store
2const createHostStore = () => {
3  return configureStore({
4    reducer: {
5      // Shared state
6      shared: sharedReducer,
7      auth: authReducer,
8
9      // Module federation containers
10      modules: modulesReducer
11    },
12    middleware: (getDefaultMiddleware) =>
13      getDefaultMiddleware()
14        .concat(moduleRegistrationMiddleware)
15        .concat(crossModuleCommunicationMiddleware),
16
17    enhancers: [
18      // Enable cross-module state sharing
19      crossModuleStateEnhancer,
20      // Module lifecycle management
21      moduleLifecycleEnhancer
22    ]
23  });
24};
25
26// Micro-frontend module registration
27const registerMicroFrontend = (
28  moduleName: string,
29  moduleStore: any,
30  stateShape: any
31) => {
32  return {
33    type: 'REGISTER_MODULE',
34    payload: {
35      moduleName,
36      reducer: moduleStore.reducer,
37      middleware: moduleStore.middleware,
38      stateShape
39    }
40  };
41};

1// Event bus for cross-module communication
2class ModuleCommunicationBus {
3  private subscribers: Map<string, Function[]> = new Map();
4
5  subscribe(eventType: string, handler: Function) {
6    if (!this.subscribers.has(eventType)) {
7      this.subscribers.set(eventType, []);
8    }
9    this.subscribers.get(eventType)!.push(handler);
10  }
11
12  publish(eventType: string, payload: any) {
13    const handlers = this.subscribers.get(eventType) || [];
14    handlers.forEach(handler => handler(payload));
15  }
16
17  // Redux integration
18  createMiddleware(): Middleware {
19    return (store) => (next) => (action) => {
20      const result = next(action);
21
22      if (action.type.startsWith('@@CROSS_MODULE/')) {
23        this.publish(action.type, {
24          action,
25          state: store.getState()
26        });
27      }
28
29      return result;
30    };
31  }
32}
33
34// Module A publishes an event
35dispatch({
36  type: '@@CROSS_MODULE/USER_PROFILE_UPDATED',
37  payload: { userId: '123', profile: updatedProfile }
38});
39
40// Module B listens for the event
41communicationBus.subscribe(
42  '@@CROSS_MODULE/USER_PROFILE_UPDATED',
43  ({ action, state }) => {
44    // Update local state based on user profile change
45    dispatch(syncUserProfile(action.payload));
46  }
47);

1// Complex entity relationships
2interface NormalizedState {
3  entities: {
4    users: { [id: string]: User };
5    articles: { [id: string]: Article };
6    comments: { [id: string]: Comment };
7    tags: { [id: string]: Tag };
8    categories: { [id: string]: Category };
9  };
10
11  relationships: {
12    userArticles: { [userId: string]: string[] };
13    articleComments: { [articleId: string]: string[] };
14    articleTags: { [articleId: string]: string[] };
15    categoryArticles: { [categoryId: string]: string[] };
16  };
17
18  indexes: {
19    articlesByDate: string[];
20    articlesByPopularity: string[];
21    usersByRole: { [role: string]: string[] };
22  };
23}
24
25// Entity normalization utility
26class EntityNormalizer {
27  static normalize<T extends { id: string }>(
28    entities: T[],
29    relationships: RelationshipMap = {}
30  ): NormalizedEntityState<T> {
31    const byId: { [id: string]: T } = {};
32    const allIds: string[] = [];
33
34    entities.forEach(entity => {
35      byId[entity.id] = entity;
36      allIds.push(entity.id);
37    });
38
39    return {
40      byId,
41      allIds,
42      relationships: this.buildRelationships(entities, relationships),
43      indexes: this.buildIndexes(entities)
44    };
45  }
46
47  static denormalize<T>(
48    ids: string[],
49    entities: { [id: string]: T },
50    relationships: RelationshipMap = {}
51  ): T[] {
52    return ids
53      .map(id => entities[id])
54      .filter(Boolean)
55      .map(entity => this.attachRelationships(entity, relationships));
56  }
57}

1// Multi-level caching system
2interface CacheState {
3  memory: {
4    hot: { [key: string]: any };      // Most frequently accessed
5    warm: { [key: string]: any };     // Recently accessed
6    cold: { [key: string]: any };     // Least recently used
7  };
8
9  persistence: {
10    localStorage: { [key: string]: any };
11    indexedDB: { [key: string]: any };
12    sessionStorage: { [key: string]: any };
13  };
14
15  network: {
16    etags: { [url: string]: string };
17    lastModified: { [url: string]: string };
18    staleWhileRevalidate: { [key: string]: any };
19  };
20
21  policies: {
22    ttl: { [key: string]: number };
23    invalidation: { [pattern: string]: string[] };
24    compression: { [key: string]: boolean };
25  };
26}
27
28// Cache management slice
29const cacheSlice = createSlice({
30  name: 'cache',
31  initialState: createInitialCacheState(),
32  reducers: {
33    cacheData: (state, action: PayloadAction<{
34      key: string;
35      data: any;
36      ttl?: number;
37      level: 'hot' | 'warm' | 'cold';
38    }>) => {
39      const { key, data, ttl, level } = action.payload;
40
41      // Store in memory cache
42      state.memory[level][key] = data;
43
44      // Set TTL if provided
45      if (ttl) {
46        state.policies.ttl[key] = Date.now() + ttl;
47      }
48
49      // Promote to hot cache if accessed frequently
50      if (level !== 'hot' && this.isFrequentlyAccessed(key)) {
51        delete state.memory[level][key];
52        state.memory.hot[key] = data;
53      }
54    },
55
56    invalidateCache: (state, action: PayloadAction<string | string[]>) => {
57      const keys = Array.isArray(action.payload) ? action.payload : [action.payload];
58
59      keys.forEach(key => {
60        delete state.memory.hot[key];
61        delete state.memory.warm[key];
62        delete state.memory.cold[key];
63        delete state.policies.ttl[key];
64      });
65    },
66
67    compactCache: (state) => {
68      const now = Date.now();
69
70      // Remove expired entries
71      Object.keys(state.policies.ttl).forEach(key => {
72        if (state.policies.ttl[key] < now) {
73          this.removeFromAllCaches(state, key);
74        }
75      });
76
77      // Move cold cache to warm if space needed
78      if (Object.keys(state.memory.cold).length > 1000) {
79        const lruKeys = this.getLRUKeys(state.memory.cold, 500);
80        lruKeys.forEach(key => delete state.memory.cold[key]);
81      }
82    }
83  }
84});

1// Circuit breaker for API calls
2class CircuitBreaker {
3  private failures: number = 0;
4  private lastFailureTime: number = 0;
5  private state: 'CLOSED' | 'OPEN' | 'HALF_OPEN' = 'CLOSED';
6
7  constructor(
8    private threshold: number = 5,
9    private timeout: number = 60000,
10    private resetTimeout: number = 30000
11  ) {}
12
13  async execute<T>(operation: () => Promise<T>): Promise<T> {
14    if (this.state === 'OPEN') {
15      if (Date.now() - this.lastFailureTime >= this.resetTimeout) {
16        this.state = 'HALF_OPEN';
17      } else {
18        throw new Error('Circuit breaker is OPEN');
19      }
20    }
21
22    try {
23      const result = await operation();
24      this.onSuccess();
25      return result;
26    } catch (error) {
27      this.onFailure();
28      throw error;
29    }
30  }
31
32  private onSuccess() {
33    this.failures = 0;
34    this.state = 'CLOSED';
35  }
36
37  private onFailure() {
38    this.failures++;
39    this.lastFailureTime = Date.now();
40
41    if (this.failures >= this.threshold) {
42      this.state = 'OPEN';
43    }
44  }
45}
46
47// Integration with Redux thunks
48const apiCircuitBreaker = new CircuitBreaker(5, 60000, 30000);
49
50export const fetchDataWithCircuitBreaker = createAsyncThunk(
51  'data/fetchWithCircuitBreaker',
52  async (params: any, { rejectWithValue }) => {
53    try {
54      return await apiCircuitBreaker.execute(() =>
55        fetch('/api/data').then(res => res.json())
56      );
57    } catch (error) {
58      return rejectWithValue({
59        message: error instanceof Error ? error.message : 'Circuit breaker error',
60        type: 'CIRCUIT_BREAKER_ERROR'
61      });
62    }
63  }
64);

1// State backup and recovery system
2const stateRecoverySlice = createSlice({
3  name: 'recovery',
4  initialState: {
5    snapshots: [] as StateSnapshot[],
6    currentSnapshot: null as StateSnapshot | null,
7    recoveryMode: false,
8    autoBackupEnabled: true
9  },
10  reducers: {
11    createSnapshot: (state, action: PayloadAction<{ label: string; appState: any }>) => {
12      const snapshot: StateSnapshot = {
13        id: generateId(),
14        label: action.payload.label,
15        timestamp: Date.now(),
16        state: action.payload.appState,
17        version: '1.0.0'
18      };
19
20      state.snapshots.push(snapshot);
21
22      // Keep only last 10 snapshots
23      if (state.snapshots.length > 10) {
24        state.snapshots = state.snapshots.slice(-10);
25      }
26    },
27
28    restoreFromSnapshot: (state, action: PayloadAction<string>) => {
29      const snapshot = state.snapshots.find(s => s.id === action.payload);
30      if (snapshot) {
31        state.currentSnapshot = snapshot;
32        state.recoveryMode = true;
33      }
34    },
35
36    exitRecoveryMode: (state) => {
37      state.recoveryMode = false;
38      state.currentSnapshot = null;
39    }
40  }
41});
42
43// Auto-backup middleware
44const autoBackupMiddleware: Middleware = (store) => (next) => (action) => {
45  const result = next(action);
46
47  const state = store.getState() as RootState;
48
49  // Create automatic backups on critical actions
50  if (action.type.includes('DELETE') || action.type.includes('RESET')) {
51    store.dispatch(createSnapshot({
52      label: `Auto-backup before ${action.type}`,
53      appState: state
54    }));
55  }
56
57  return result;
58};

1// Virtual state management for large datasets
2interface VirtualState<T> {
3  visibleRange: { start: number; end: number };
4  bufferSize: number;
5  totalItems: number;
6  loadedChunks: Map<number, T[]>;
7  loadingChunks: Set<number>;
8}
9
10const createVirtualSlice = <T>(name: string) => createSlice({
11  name,
12  initialState: {
13    visibleRange: { start: 0, end: 100 },
14    bufferSize: 50,
15    totalItems: 0,
16    loadedChunks: new Map(),
17    loadingChunks: new Set()
18  } as VirtualState<T>,
19  reducers: {
20    setVisibleRange: (state, action: PayloadAction<{ start: number; end: number }>) => {
21      state.visibleRange = action.payload;
22
23      // Trigger loading for chunks that are needed but not loaded
24      const requiredChunks = this.getRequiredChunks(action.payload, state.bufferSize);
25      requiredChunks.forEach(chunkIndex => {
26        if (!state.loadedChunks.has(chunkIndex) && !state.loadingChunks.has(chunkIndex)) {
27          state.loadingChunks.add(chunkIndex);
28          // Dispatch async action to load chunk
29        }
30      });
31    },
32
33    chunkLoaded: (state, action: PayloadAction<{ chunkIndex: number; data: T[] }>) => {
34      const { chunkIndex, data } = action.payload;
35      state.loadedChunks.set(chunkIndex, data);
36      state.loadingChunks.delete(chunkIndex);
37    },
38
39    unloadDistantChunks: (state) => {
40      const { start, end } = state.visibleRange;
41      const keepDistance = state.bufferSize * 2;
42
43      state.loadedChunks.forEach((_, chunkIndex) => {
44        const chunkStart = chunkIndex * 100;
45        const chunkEnd = chunkStart + 100;
46
47        if (chunkEnd < start - keepDistance || chunkStart > end + keepDistance) {
48          state.loadedChunks.delete(chunkIndex);
49        }
50      });
51    }
52  }
53});

1// Web Worker integration for heavy computations
2class StateProcessingWorker {
3  private worker: Worker;
4  private taskQueue: Map<string, { resolve: Function; reject: Function }> = new Map();
5
6  constructor() {
7    this.worker = new Worker('/workers/state-processor.js');
8    this.worker.onmessage = this.handleWorkerMessage.bind(this);
9  }
10
11  async processLargeDataset(data: any[], operation: string): Promise<any> {
12    const taskId = generateId();
13
14    return new Promise((resolve, reject) => {
15      this.taskQueue.set(taskId, { resolve, reject });
16
17      this.worker.postMessage({
18        taskId,
19        operation,
20        data
21      });
22    });
23  }
24
25  private handleWorkerMessage(event: MessageEvent) {
26    const { taskId, result, error } = event.data;
27    const task = this.taskQueue.get(taskId);
28
29    if (task) {
30      if (error) {
31        task.reject(new Error(error));
32      } else {
33        task.resolve(result);
34      }
35      this.taskQueue.delete(taskId);
36    }
37  }
38}
39
40// Background processing thunk
41export const processDataInBackground = createAsyncThunk(
42  'data/processInBackground',
43  async (data: any[], { dispatch }) => {
44    const worker = new StateProcessingWorker();
45
46    try {
47      // Show loading state
48      dispatch(setProcessingState('loading'));
49
50      // Process data in web worker
51      const result = await worker.processLargeDataset(data, 'normalize');
52
53      // Update state with processed data
54      dispatch(setProcessingState('completed'));
55      return result;
56    } catch (error) {
57      dispatch(setProcessingState('error'));
58      throw error;
59    }
60  }
61);

1// State migration system
2interface StateVersion {
3  version: string;
4  migrate: (oldState: any) => any;
5  validate: (state: any) => boolean;
6}
7
8const stateMigrations: StateVersion[] = [
9  {
10    version: '1.0.0',
11    migrate: (state: any) => state,
12    validate: (state: any) => !!state.users
13  },
14  {
15    version: '1.1.0',
16    migrate: (state: any) => ({
17      ...state,
18      users: {
19        ...state.users,
20        profiles: state.users.users.map(user => ({
21          ...user,
22          preferences: {}
23        }))
24      }
25    }),
26    validate: (state: any) => !!state.users.profiles
27  },
28  {
29    version: '2.0.0',
30    migrate: (state: any) => ({
31      userManagement: {
32        users: state.users,
33        authentication: state.auth
34      },
35      contentManagement: {
36        articles: state.articles || {}
37      }
38    }),
39    validate: (state: any) => !!state.userManagement && !!state.contentManagement
40  }
41];
42
43const migrateState = (persistedState: any, currentVersion: string): any => {
44  const stateVersion = persistedState._version || '1.0.0';
45
46  if (stateVersion === currentVersion) {
47    return persistedState;
48  }
49
50  let migratedState = persistedState;
51  let currentIndex = stateMigrations.findIndex(m => m.version === stateVersion);
52
53  if (currentIndex === -1) {
54    throw new Error(`Unknown state version: ${stateVersion}`);
55  }
56
57  // Apply migrations sequentially
58  for (let i = currentIndex + 1; i < stateMigrations.length; i++) {
59    const migration = stateMigrations[i];
60    migratedState = migration.migrate(migratedState);
61
62    if (!migration.validate(migratedState)) {
63      throw new Error(`State migration to ${migration.version} failed validation`);
64    }
65
66    migratedState._version = migration.version;
67
68    if (migration.version === currentVersion) {
69      break;
70    }
71  }
72
73  return migratedState;
74};

1// Production monitoring system
2class StateMonitor {
3  private metrics: Map<string, any> = new Map();
4  private alerts: AlertRule[] = [];
5
6  constructor(private config: MonitoringConfig) {
7    this.setupPerformanceObserver();
8    this.setupErrorTracking();
9  }
10
11  trackStateChange(action: any, prevState: any, nextState: any) {
12    const stateSize = JSON.stringify(nextState).length;
13    const actionDuration = performance.now() - action.timestamp;
14
15    this.metrics.set('stateSize', stateSize);
16    this.metrics.set('lastActionDuration', actionDuration);
17
18    // Check for performance issues
19    if (stateSize > this.config.maxStateSize) {
20      this.triggerAlert('STATE_SIZE_EXCEEDED', { stateSize });
21    }
22
23    if (actionDuration > this.config.slowActionThreshold) {
24      this.triggerAlert('SLOW_ACTION', { action: action.type, duration: actionDuration });
25    }
26
27    // Send to analytics service
28    if (this.config.enableAnalytics) {
29      this.sendAnalytics({
30        event: 'state_change',
31        action: action.type,
32        duration: actionDuration,
33        stateSize
34      });
35    }
36  }
37
38  private setupPerformanceObserver() {
39    if ('PerformanceObserver' in window) {
40      const observer = new PerformanceObserver((list) => {
41        list.getEntries().forEach((entry) => {
42          if (entry.name.includes('redux')) {
43            this.metrics.set('performanceEntry', entry);
44          }
45        });
46      });
47
48      observer.observe({ entryTypes: ['measure'] });
49    }
50  }
51
52  private triggerAlert(type: string, data: any) {
53    const alert = {
54      type,
55      timestamp: Date.now(),
56      data,
57      severity: this.getAlertSeverity(type)
58    };
59
60    // Send to monitoring service
61    if (this.config.alertWebhook) {
62      fetch(this.config.alertWebhook, {
63        method: 'POST',
64        headers: { 'Content-Type': 'application/json' },
65        body: JSON.stringify(alert)
66      });
67    }
68  }
69}
70
71// Monitoring middleware
72const monitoringMiddleware: Middleware = (store) => (next) => (action) => {
73  const startTime = performance.now();
74  const prevState = store.getState();
75
76  const result = next(action);
77
78  const endTime = performance.now();
79  const nextState = store.getState();
80
81  // Track performance and state changes
82  stateMonitor.trackStateChange(
83    { ...action, timestamp: startTime, duration: endTime - startTime },
84    prevState,
85    nextState
86  );
87
88  return result;
89};

1// Environment-specific store configuration
2const createProductionStore = (preloadedState?: any) => {
3  const middleware = [
4    // Core middleware
5    thunk,
6
7    // Production middleware
8    ...(process.env.NODE_ENV === 'production'
9      ? [monitoringMiddleware, errorReportingMiddleware]
10      : [loggerMiddleware, devToolsMiddleware]
11    ),
12
13    // Feature flags middleware
14    featureFlagsMiddleware,
15
16    // Performance middleware
17    performanceMiddleware
18  ];
19
20  return configureStore({
21    reducer: rootReducer,
22    middleware,
23    preloadedState: preloadedState ? migrateState(preloadedState, CURRENT_VERSION) : undefined,
24    devTools: process.env.NODE_ENV !== 'production',
25
26    // Production optimizations
27    immutableCheck: process.env.NODE_ENV !== 'production',
28    serializableCheck: process.env.NODE_ENV !== 'production' ? {
29      ignoredActions: ['persist/PERSIST', 'analytics/track']
30    } : false
31  });
32};
33
34// Feature flags integration
35const featureFlagsMiddleware: Middleware = (store) => (next) => (action) => {
36  const state = store.getState() as RootState;
37  const featureFlags = state.featureFlags;
38
39  // Block actions based on feature flags
40  if (action.type.startsWith('newFeature/') && !featureFlags.newFeatureEnabled) {
41    console.warn(`Action ${action.type} blocked by feature flag`);
42    return;
43  }
44
45  return next(action);
46};

1// Advanced persistence strategy
2class StatePersistence {
3  private storage: Storage;
4  private compression: boolean;
5  private encryption: boolean;
6
7  constructor(config: PersistenceConfig) {
8    this.storage = config.storage;
9    this.compression = config.compression || false;
10    this.encryption = config.encryption || false;
11  }
12
13  async persistState(state: any): Promise<void> {
14    try {
15      let serializedState = JSON.stringify(state);
16
17      if (this.compression) {
18        serializedState = await this.compress(serializedState);
19      }
20
21      if (this.encryption) {
22        serializedState = await this.encrypt(serializedState);
23      }
24
25      this.storage.setItem('appState', serializedState);
26    } catch (error) {
27      console.error('Failed to persist state:', error);
28    }
29  }
30
31  async loadState(): Promise<any | undefined> {
32    try {
33      let serializedState = this.storage.getItem('appState');
34
35      if (!serializedState) {
36        return undefined;
37      }
38
39      if (this.encryption) {
40        serializedState = await this.decrypt(serializedState);
41      }
42
43      if (this.compression) {
44        serializedState = await this.decompress(serializedState);
45      }
46
47      return JSON.parse(serializedState);
48    } catch (error) {
49      console.error('Failed to load state:', error);
50      return undefined;
51    }
52  }
53}
54
55// State hydration with validation
56const hydrateStore = async (): Promise<Store> => {
57  const persistence = new StatePersistence({
58    storage: localStorage,
59    compression: true,
60    encryption: false
61  });
62
63  const persistedState = await persistence.loadState();
64
65  if (persistedState) {
66    // Validate persisted state
67    const isValid = validateStateSchema(persistedState);
68
69    if (isValid) {
70      const migratedState = migrateState(persistedState, CURRENT_VERSION);
71      return createProductionStore(migratedState);
72    } else {
73      console.warn('Invalid persisted state, using default state');
74    }
75  }
76
77  return createProductionStore();
78};