Clean up old external ingest file sets if we have too many (#2899)

* Clean up old file sets if we have too many

* Update src/platform/workspaceChunkSearch/node/codeSearch/externalIngestClient.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update src/platform/workspaceChunkSearch/node/codeSearch/externalIngestClient.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: mjbvz

src/platform/workspaceChunkSearch/node/codeSearch/externalIngestClient.ts

@@ -9,7 +9,6 @@ import crypto from 'crypto';
 import fs from 'fs';
 import { CancellationToken } from 'vscode-languageserver-protocol';
 import { Result } from '../../../../util/common/result';
-import { coalesce } from '../../../../util/vs/base/common/arrays';
 import { raceCancellationError } from '../../../../util/vs/base/common/async';
 import { CancellationError } from '../../../../util/vs/base/common/errors';
 import { Disposable } from '../../../../util/vs/base/common/lifecycle';
@@ -167,19 +166,50 @@ export class ExternalIngestClient extends Disposable implements IExternalIngestC
 		}
 
 		onProgress?.(l10n.t('Creating snapshot...'));
+
 		// Create snapshot - this endpoint could return 429 if you already have too many filesets
-		let createIngestResponse: Response;
-		try {
-			createIngestResponse = await this.post(authToken, '/external/code/ingest', {
+		const createIngest = async (): Promise<Response> => {
+			return this.post(authToken, '/external/code/ingest', {
 				fileset_name: filesetName,
 				new_checkpoint: newCheckpoint,
 				geo_filter: Buffer.from(geoFilter.toBytes()).toString('base64'),
 				coded_symbols: codedSymbols,
 			}, token);
+		};
+
+		let createIngestResponse: Response;
+		try {
+			createIngestResponse = await createIngest();
 		} catch (err) {
 			throw new Error('Exception during create ingest', err);
 		}
 
+		// Handle 429 by cleaning up old filesets and retrying
+		if (createIngestResponse.status === 429) {
+			this.logService.info('ExternalIngestClient::updateIndex(): Got 429, cleaning up old filesets...');
+			onProgress?.(l10n.t("Too many filesets, cleaning up old ones..."));
+
+			await raceCancellationError(this.cleanupOldFilesets(authToken, filesetName, token), token);
+
+			// Retry the create ingest
+			this.logService.info('ExternalIngestClient::updateIndex(): Retrying create ingest after cleanup...');
+			onProgress?.(l10n.t("Retrying snapshot creation..."));
+			try {
+				createIngestResponse = await createIngest();
+			} catch (err) {
+				throw new Error('Exception during create ingest retry', err);
+			}
+
+			// If we still get 429 after cleanup and retry, fail with a clear error
+			if (createIngestResponse.status === 429) {
+				throw new Error('Create ingest failed with 429 Too Many Requests even after cleanup.');
+			}
+		}
+
+		// Fail fast on non-OK responses before attempting to parse JSON
+		if (!createIngestResponse.ok) {
+			throw new Error(`Create ingest failed with status ${createIngestResponse.status}`);
+		}
 		interface CodedSymbolRange {
 			readonly start: number;
 			readonly end: number;
@@ -362,6 +392,11 @@ export class ExternalIngestClient extends Disposable implements IExternalIngestC
 			return [];
 		}
 
+		const filesets = await this.listFilesetsWithDetails(authToken, token);
+		return filesets.map(x => x.name);
+	}
+
+	private async listFilesetsWithDetails(authToken: string, token: CancellationToken): Promise<Array<{ name: string; checkpoint: string; status: string }>> {
 		const resp = await this.apiClient.makeRequest(
 			`${ExternalIngestClient.baseUrl}/external/code/ingest`,
 			this.getHeaders(authToken),
@@ -371,7 +406,20 @@ export class ExternalIngestClient extends Disposable implements IExternalIngestC
 		);
 
 		const body = await resp.json() as { filesets?: Array<{ name: string; checkpoint: string; status: string }>; max_filesets: number };
-		return coalesce((body.filesets ?? []).map(x => x.name));
+		return body.filesets ?? [];
+	}
+
+	/**
+	 * Cleans up old filesets to make room for new ones.
+	 */
+	private async cleanupOldFilesets(authToken: string, currentFilesetName: string, token: CancellationToken): Promise<void> {
+		const filesets = await this.listFilesetsWithDetails(authToken, token);
+
+		const candidates = filesets.filter(f => f.name !== currentFilesetName);
+		const toDelete = candidates.at(-1);
+		if (toDelete) {
+			await this.deleteFilesetByName(authToken, toDelete.name, token);
+		}
 	}
 
 	async deleteFileset(filesetName: string, token: CancellationToken): Promise<void> {