backend: add index migration functionality to MigrationService

meet-ce/backend/src/services/migration.service.ts

@@ -28,6 +28,10 @@ export class MigrationService {
 	 * This method should be called during startup to ensure backwards compatibility.
 	 *
 	 * Uses distributed locking to ensure only one instance runs migrations in HA mode.
+	 *
+	 * Migration flow:
+	 * 1) Schema/data migrations
+	 * 2) Index synchronization (drop obsolete + create missing indexes)
 	 */
 	async runMigrations(): Promise<void> {
 		this.logger.info('Running migrations...');
@@ -48,6 +52,9 @@ export class MigrationService {
 			// Run schema migrations to upgrade document structures
 			await this.runSchemaMigrations();
 
+			// Sync collection indexes to match current schema definitions
+			await this.runIndexMigrations();
+
 			this.logger.info('All migrations completed successfully');
 		} catch (error) {
 			this.logger.error('Error running migrations:', error);
@@ -61,6 +68,59 @@ export class MigrationService {
 		}
 	}
 
+	/**
+	 * Synchronizes MongoDB indexes for all registered collections.
+	 * This removes obsolete indexes and creates missing ones according to the current schema definitions.
+	 */
+	protected async runIndexMigrations(): Promise<void> {
+		this.logger.info('Running index migrations...');
+
+		try {
+			for (const registry of runtimeMigrationRegistry) {
+				await this.syncCollectionIndexes(registry);
+			}
+
+			this.logger.info('Index migrations completed successfully');
+		} catch (error) {
+			this.logger.error('Error running index migrations:', error);
+			throw error;
+		}
+	}
+
+	/**
+	 * Synchronizes indexes for a single collection.
+	 *
+	 * @param registry - The collection migration registry containing model and collection metadata
+	 */
+	protected async syncCollectionIndexes<TDocument extends SchemaMigratableDocument>(
+		registry: CollectionMigrationRegistry<TDocument>
+	): Promise<void> {
+		this.logger.info(`Syncing indexes for collection: ${registry.collectionName}`);
+
+		const indexesBeforeSync = await registry.model.collection.indexes();
+		const indexNamesBeforeSync = new Set(indexesBeforeSync.map((index) => index.name));
+
+		const droppedIndexes = await registry.model.syncIndexes();
+
+		const indexesAfterSync = await registry.model.collection.indexes();
+		const indexNamesAfterSync = new Set(indexesAfterSync.map((index) => index.name));
+
+		const createdIndexes = Array.from(indexNamesAfterSync).filter(
+			(indexName) => !indexNamesBeforeSync.has(indexName)
+		);
+
+		if (droppedIndexes.length === 0 && createdIndexes.length === 0) {
+			this.logger.debug(`No index changes for collection: ${registry.collectionName}`);
+			return;
+		}
+
+		this.logger.info(
+			`Index sync for ${registry.collectionName}: ` +
+				`dropped=${droppedIndexes.length} [${droppedIndexes.join(', ')}], ` +
+				`created=${createdIndexes.length} [${createdIndexes.join(', ')}]`
+		);
+	}
+
 	/**
 	 * Runs all schema migrations to upgrade document structures to the latest version.
 	 * Processes each collection in the registry and executes pending migrations.