Evict proxies not returned by sources for >3 refresh cycles and not
currently alive. Cleans up proxies removed upstream faster than waiting
for max_fails consecutive health test failures.
Track last_fail timestamp on ProxyEntry. When a connection attempt fails
in server.py, report_failure() records the time. The selection weight
multiplies by min(fail_age/60, 1.0), ramping back from floor over 60s.
Prevents wasting retries on proxies that just failed.
Replace uniform random.choice with random.choices weighted by last_ok
recency. Proxies tested successfully more recently get higher selection
probability (weight = 1/(1 + age/300)), decaying over ~5 minutes.
ProxyPool replaces ProxySource with:
- Multiple sources: HTTP APIs and text files (one proxy URL per line)
- Deduplication by proto://host:port
- Health testing: full chain test with configurable concurrency
- Mass-failure guard: skip eviction when >90% fail
- Background loops for periodic refresh and health checks
- JSON state persistence with atomic writes (warm starts)
- Backward compat: ProxySource still works for legacy configs
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>