Technologies/Django/django.cache.misses
DjangoDjangoMetric

django.cache.misses

Unsuccessful cache retrievals
Dimensions:None
Available on:DatadogDatadog (1)
Interface Metrics (1)
DatadogDatadog
Number of unsuccessful cache retrievals
Dimensions:None
Sources
django.cache.missesdocs.datadoghq.com

Technical Annotations (38)

Configuration Parameters (12)
shared_buffers
PostgreSQL memory cache size - increase if cache hit ratio is low
lock.timeoutrecommended: 5
Prevents deadlocks if worker crashes during cache computation
timeoutrecommended: 60 * 60
Cache expiry in seconds; example shows 1 hour for redis_cache.set()
CACHES.BACKENDrecommended: django.core.cache.backends.memcached.PyMemcacheCache
Memcached backend loses data on restart
CACHES.OPTIONS.CULL_FREQUENCYrecommended: 3
default value; 0 dumps entire cache, 2 culls half, 3 culls one-third
CACHES.OPTIONS.MAX_ENTRIESrecommended: 300
cache capacity threshold that triggers culling
CACHES.default.BACKENDrecommended: django.core.cache.backends.redis.RedisCache or django.core.cache.backends.memcached.MemcachedCache
Use shared backend instead of locmem for production
CACHES.view_name.BACKENDrecommended: django.core.cache.backends.locmem.LocMemCache
Define separate cache backend for each view group to enable selective clearing
CACHES.view_name.LOCATIONrecommended: unique_location_name
Required when using separate LocMemCache instances
LOCATIONrecommended: 127.0.0.1:11211
must point to running Memcached server address and port
HITCOUNT_CACHE_TIMEOUTrecommended: 1800
Must exceed HITCOUNT_PERSIST_SCHEDULE to prevent hit data loss
HITCOUNT_PERSIST_SCHEDULErecommended: 10
Must be less than HITCOUNT_CACHE_TIMEOUT; value in minutes
Error Signatures (1)
ConnectionRefusedError: [Errno 111] Connection refusedexception
CLI Commands (2)
with cache.lock(f"lock:user_profile:{user_id}", timeout=5):remediation
python manage.py persist_hitsremediation
Technical References (23)
Django Debug Toolbarcomponentcache panelcomponentRediscomponentdjango_cache_get_hits_totalcomponentdjango_cache_get_misses_totalcomponentTTLconceptpost_savecomponentpost_deletecomponentcache.lock()componentcache stampedeconceptthundering herdconceptDjango signalscomponentDRF cachingcomponentRedisCachecomponentredis_cache.setcomponentdatetime.datetime.now()componentdateutil.parser.parse()componentLocMemCachecomponentdjango.core.cache.backends.locmem.LocMemCachecomponent@cache_pagecomponentkey_prefixcomponentMemcachedCachecomponentmemcachecomponent
Related Insights (18)
Low cache hit ratio indicates ineffective cache configurationinfo
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Repeatedly called endpoints without caching increase database loadwarning
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Cache hit ratio below 70% indicates inefficient cachingwarning
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Stale cached QuerySet data from missing invalidationwarning
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Cache stampede causes database overload on cold cachewarning
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Missing cache invalidation causes stale data to be served to userswarning
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Improper cache expiry time causes stale data or server overloadwarning
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Memcached data loss on server crash or restartwarning
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Local-memory cache inefficient in multi-process deploymentswarning
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CULL_FREQUENCY=0 causes full cache dump at capacitywarning
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Timestamp-based cache invalidation eliminates deletion overheadinfo
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LocMemCache creates isolated per-process cache instanceswarning
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Cache bloat from @cache_page decorator over-cachinginfo
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Memcached server unreachable causes connection refusedcritical
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Hit data loss due to cache expiration before persistencewarning
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Cache hit ratio below 85% indicates optimization neededwarning
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Improper cache invalidation serves stale data to userswarning
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Inadequate serialization causes polymorphic cache misseswarning
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