SvelteKit部署Vercel后随机函数崩溃问题求助

问题描述 #

我开发的SvelteKit电商应用在本地运行完全正常，但部署到Vercel后会随机出现函数崩溃，所有URL都受影响，这严重影响了电商转化率。已经尝试更换svelte.config.js中的适配器为@sveltejs/adapter-vercel，但问题仍未解决。

错误日志 #

[GET] /proizvodi/9?fbclid=PAAaY2n3yQfX-Wzxs5pTMWeP9nMUkdIv2V4qg8kObIDQgUAdPnwLtWEr4ICYg_aem_AT5iXQ0y2WTFTVjFAkqIfOf-vx44GuIUXoJKxT5IunSH48Cf1QVjlfC8Q1rKapxuuR9daAL70GWwpLZ_rINriwy815oEYfwfXFvOuh3HvHBvhWRFkVdfeQom7PK6UZvTp0s
02:39:09:44
2023-01-26T01:39:09.507Z    f0d6641c-416c-4c0a-ba67-c59890f6f936    ERROR   [2023-01-26T01:39:09.507Z]  @firebase/firestore: Firestore (9.15.0): Could not reach Cloud Firestore backend. Backend didn't respond within 10 seconds.
This typically indicates that your device does not have a healthy Internet connection at the moment. The client will operate in offline mode until it is able to successfully connect to the backend.
2023-01-26T01:39:09.539Z    efb98c51-3cde-4791-981f-5d22145fe3c0    ERROR   Unhandled Promise Rejection     {"errorType":"Runtime.UnhandledPromiseRejection","errorMessage":"TypeError: fetch failed","reason":{"errorType":"TypeError","errorMessage":"fetch failed","cause":{"errorType":"Error","errorMessage":"Client network socket disconnected before secure TLS connection was established","code":"ECONNRESET","host":"translate.googleapis.com","port":443,"localAddress":null,"stack":["Error: Client network socket disconnected before secure TLS connection was established","    at connResetException (node:internal/errors:711:14)","    at TLSSocket.onConnectEnd (node:_tls_wrap:1593:19)","    at TLSSocket.emit (node:events:525:35)","    at endReadableNT (node:internal/streams/readable:1359:12)","    at process.processTicksAndRejections (node:internal/process/task_queues:82:21)"]},"stack":["TypeError: fetch failed","    at fetch (/var/task/node_modules/undici/index.js:105:13)","    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)"]},"promise":{},"stack":["Runtime.UnhandledPromiseRejection: TypeError: fetch failed","    at process.<anonymous> (file:///var/runtime/index.mjs:1194:17)","    at process.emit (node:events:525:35)","    at emit (node:internal/process/promises:149:20)","    at processPromiseRejections (node:internal/process/promises:283:27)","    at process.processTicksAndRejections (node:internal/process/task_queues:96:32)"]}
Unknown application error occurred
Runtime.Unknown

解决方案 #

1. 处理Firestore连接超时问题 #

• 给Firestore请求添加重试逻辑，避免单次网络波动导致超时。可以封装Firestore调用函数，在超时或连接失败时自动重试2-3次：

  import { getFirestore } from 'firebase/firestore';
  
  async function firestoreRequestWithRetry(fn, retries = 3) {
    try {
      return await fn();
    } catch (error) {
      if (retries > 0 && error.message.includes('Could not reach Cloud Firestore backend')) {
        await new Promise(resolve => setTimeout(resolve, 1500));
        return firestoreRequestWithRetry(fn, retries - 1);
      }
      throw error;
    }
  }
  
  // 使用示例
  const db = getFirestore();
  const doc = await firestoreRequestWithRetry(() => getDoc(doc(db, 'proizvodi', '9')));
  

• 检查Vercel的区域配置，选择距离Firestore实例最近的部署区域，减少网络延迟。

2. 修复Google翻译API的TLS连接重置问题 #

• 为调用translate.googleapis.com的fetch请求添加重试机制，针对ECONNRESET错误进行重试：

  async function fetchTranslateWithRetry(url, options = {}, retries = 3) {
    try {
      return await fetch(url, options);
    } catch (error) {
      if (retries > 0 && error.cause?.code === 'ECONNRESET') {
        await new Promise(resolve => setTimeout(resolve, 1000));
        return fetchTranslateWithRetry(url, options, retries - 1);
      }
      throw error;
    }
  }
  

• 确认项目使用的Node.js版本与Vercel配置一致，在package.json中指定版本：

  "engines": {
    "node": ">=18.x"
  }
  

3. 捕获未处理的Promise拒绝 #

在SvelteKit的hooks.server.js中添加全局捕获逻辑，避免未处理的Promise直接导致函数崩溃：

process.on('unhandledRejection', (reason, promise) => {
  console.error('未处理的Promise拒绝:', reason);
  // 可添加日志上报等兜底处理
});

内容的提问来源于stack exchange，提问作者Jaksa