sadpandajoe commented on code in PR #43215: URL: https://github.com/apache/superset/pull/43215#discussion_r3978968732
########## superset-frontend/src/utils/lazyWithRetry.ts: ########## @@ -0,0 +1,120 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +import { LazyExoticComponent, lazy } from 'react'; + +/** + * `React.lazy` memoizes the *rejection* of its factory: once the dynamic + * `import()` behind a route fails (a chunk that 404s after a redeploy, or a + * transient 502/503 from the asset server), the payload is permanently marked + * as rejected and the component throws `ChunkLoadError` forever - even after + * the asset becomes reachable again and even when the user navigates away and + * back. Retrying the import *inside* the factory, before the promise handed to + * `React.lazy` settles, is the only way to recover from a transient failure. + * + * See https://github.com/apache/superset/issues/41266 + */ +export const DEFAULT_LAZY_RETRIES = 2; +export const DEFAULT_LAZY_RETRY_DELAY_MS = 500; + +export interface LazyRetryOptions { + /** Number of *additional* attempts made after the first one fails. */ + retries?: number; + /** Base delay between attempts; doubled on every subsequent attempt. */ + retryDelayMs?: number; + /** + * Predicate deciding whether an error is worth retrying. Defaults to + * `isChunkLoadError` so deterministic failures (syntax errors, missing + * dependencies, module-evaluation errors) surface immediately instead of + * being retried. + */ + isRetryable?: (error: unknown) => boolean; +} + +/** + * Recognizes the transient "chunk failed to load" errors browsers/bundlers + * raise on a stale or momentarily-unreachable asset, as opposed to + * deterministic module errors (syntax errors, missing dependencies) that + * will fail identically on every retry. + */ +export const isChunkLoadError = (error: unknown): boolean => + error instanceof Error && + (error.name === 'ChunkLoadError' || + /loading chunk|failed to fetch dynamically imported module/i.test( + error.message, + )); + +const sleep = (ms: number): Promise<void> => + new Promise(resolve => { + setTimeout(resolve, ms); + }); + +/** + * Calls `factory`, retrying with exponential backoff when it rejects with a + * retryable error. Rejects with the last error once every attempt has been + * exhausted, or immediately when the error is not retryable. + */ +export async function retryImport<T>( + factory: () => Promise<T>, + { + retries = DEFAULT_LAZY_RETRIES, + retryDelayMs = DEFAULT_LAZY_RETRY_DELAY_MS, + isRetryable = isChunkLoadError, + }: LazyRetryOptions = {}, +): Promise<T> { + let lastError: unknown; + for (let attempt = 0; attempt <= retries; attempt += 1) { + try { + // eslint-disable-next-line no-await-in-loop + return await factory(); + } catch (error) { + lastError = error; + if (attempt < retries && isRetryable(error)) { + // eslint-disable-next-line no-await-in-loop + await sleep(retryDelayMs * 2 ** attempt); Review Comment: A transient asset-server 502/503 can fail this import for many clients at once, and this fixed schedule makes every affected browser retry again at the same 500 and 1,500 ms offsets, recreating the burst against the already-overloaded server. Could this use a jittered delay, as the client retry path does, to avoid synchronizing retries? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
