dogpile.cache
Advanced caching library for Python that prevents cache stampede — provides a region-based caching system with dogpile lock to prevent multiple threads from regenerating the same expired cache entry simultaneously. dogpile.cache features: CacheRegion with make_region() factory, @cache_region.cache_on_arguments() decorator, mutex-based stampede prevention (one thread regenerates while others serve stale data), Redis/Memcached/file/memory backends, key mangling, expiration with grace period (serve stale while refreshing), async cache refresh support, invalidation, and integration with SQLAlchemy ORM. From the SQLAlchemy project.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
Use Redis TLS via arguments={'host': 'localhost', 'ssl': True}. Cache key mangling should not expose sensitive data. No plaintext passwords — use environment variables for Redis password. Pickle is default serializer for some backends — only cache trusted data.
⚡ Reliability
Best When
High-traffic caching where cache stampede (thundering herd) is a problem — dogpile.cache's mutex-based regeneration prevents expensive recomputation storms when popular cache entries expire.
Avoid When
Simple single-threaded scripts (use functools.lru_cache), low-traffic applications where stampede isn't an issue, or when cachetools/cachelib provides sufficient features.
Use Cases
- • Agent stampede-safe cache — from dogpile.cache import make_region; region = make_region().configure('dogpile.cache.redis', expiration_time=300, arguments={'host': 'localhost', 'port': 6379}); @region.cache_on_arguments(); def get_report(report_id): return compute_expensive_report(report_id) — stampede prevention; agent prevents cache stampede on popular keys; only one thread regenerates expired cache entry
- • Agent region-based caching — from dogpile.cache import make_region; short = make_region().configure('dogpile.cache.memory', expiration_time=60); long = make_region().configure('dogpile.cache.redis', expiration_time=3600); @short.cache_on_arguments(); def hot_data(key): ...; @long.cache_on_arguments(); def cold_data(key): ... — multiple regions; agent uses different TTLs for different data types
- • Agent manual cache population — region.set('key', value); cached = region.get('key'); region.delete('key') — manual ops; agent manually manages cache entries; region.get() returns NO_VALUE sentinel on miss; check: if cached is NO_VALUE: compute and store
- • Agent ORM caching — from dogpile.cache.region import make_region; query_region = make_region().configure('dogpile.cache.redis'); @query_region.cache_on_arguments(expiration_time=60); def get_user(user_id): return session.query(User).get(user_id) — SQLAlchemy integration; agent caches database query results; invalidate on write: query_region.delete('get_user|123')
- • Agent filesystem caching — region = make_region().configure('dogpile.cache.dbm', arguments={'filename': '/tmp/cache.dbm'}, expiration_time=86400); @region.cache_on_arguments(); def expensive_analysis(data_path): return analyze(data_path) — file-backed; agent persists cache to disk between process restarts using DBM file backend
Not For
- • Simple in-memory caching — dogpile.cache has significant setup overhead; for simple memoization use functools.lru_cache or cachetools
- • Real-time requirements — stampede prevention adds mutex overhead; for sub-millisecond cache access use simpler in-memory dict
- • Non-Python stacks — dogpile.cache is Python-only; for polyglot caching use Redis directly
Interface
Authentication
Auth via backend arguments: Redis password in arguments dict. No auth for memory/file backends.
Pricing
dogpile.cache is MIT licensed. Free for all use.
Agent Metadata
Known Gotchas
- ⚠ region.get() returns NO_VALUE not None on cache miss — from dogpile.cache.api import NO_VALUE; cached = region.get('key'); if cached is NO_VALUE: compute; agent code checking: if cached is None fails because dogpile returns NO_VALUE sentinel; always check: cached is NO_VALUE not cached is None for miss detection
- ⚠ make_region().configure() returns the region — region = make_region() creates unconfigured region; region.configure(...) configures it and returns the same region object; agent code must call configure() before first cache operation; calling get()/set() on unconfigured region raises RegionAlreadyConfigured or AttributeError
- ⚠ @cache_on_arguments creates cache key from function name + arguments — key includes module path + function name + str(args); functions with same name in different modules share cache keys if not careful; agent code: use expiration_time parameter per-decorator not just region-wide; use region.key_mangler to customize key format
- ⚠ dogpile lock is per-key not per-region — stampede prevention uses one lock per unique cache key; if 1000 unique keys expire simultaneously, 1000 locks created; agent code with many unique key patterns under high load: monitor lock count; dogpile is designed for popular keys not massive unique key spaces
- ⚠ Invalidation requires knowing the exact key — region.delete(key) requires the mangled key string; for function caches: region.delete(function_key_creator(func, *args)); dogpile has no 'delete by prefix' for Redis; agent code invalidating function cache: call region.cache_on_arguments().get(func).invalidate(*args) helper
- ⚠ configure() cannot be called twice on same region — production pattern: create regions at module level; test code that reconfigures regions gets RegionAlreadyConfigured; agent test code: create fresh region per test or use mock region; in-process region reconfiguration not supported
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for dogpile.cache.
Scores are editorial opinions as of 2026-03-06.