Building a Resilient Web Scraping Engine: Tiered Fallbacks, Fingerprint Spoofing, and SQLite Checkpoints

说明与用途

构建了一个自主的 CLI 爬虫引擎，使用快速 HTTPX，必要时升级到 stealth Playwright，并将状态持久化到 ACID 兼容的 SQLite 数据库，实现高效、可靠的爬取。

问题

Custom web scrapers often fail due to static request patterns, headless overhead, and volatile in‑memory state, leading to IP bans, slow throughput, and lost progress.

结果

The tiered engine achieves high throughput, reduces compute waste, and guarantees progress recovery, eliminating the need for paid extraction APIs.

工作流

• Seed URLs into SQLite queue with statuses PENDING/IN_FLIGHT/COMPLETED/FAILED
• Tier 1: async HTTPX request with randomized User‑Agent and TLS spoofing
• Detect anti‑bot challenges (403/503/CAPTCHA/Cloudflare) and trigger escalation
• Tier 2: launch patched Playwright context, execute JS challenges, extract payload
• Atomic SQLite writes for checkpointing; resume on interruption without duplication
• Emit extracted JSON to Postgres or other sinks

证据

Firing 10,000 raw requests.get() calls with static User‑Agents results in an immediate IP burn or 403 Forbidden via Cloudflare Bot Management or Akamai.

来源

Running full Chromium instances for every single page request wastes compute, causes memory leaks, and slows down throughput by 800%.

来源

When an unhandled exception or 429 Too Many Requests crashes the process 8 hours into a 100,000-page crawl, developers without persistent state lose progress and re‑scrape identical records, burning proxy bandwidth.

来源