Create custom CacheManager

backend/clubs/utils.py

@@ -1,17 +1,24 @@
 import io
+import logging
 import re
 from urllib.parse import urlparse
 
 import bleach
 import requests
 from bs4 import BeautifulSoup, Comment, NavigableString
 from django.conf import settings
+from django.core.cache import caches
+from django.core.cache.backends.base import BaseCache
 from django.core.files.images import ImageFile
 from django.db.models import CharField, F, Q, Value
 from django.template.defaultfilters import slugify
 from PIL import Image
 
 
+logging.basicConfig()
+logger = logging.getLogger(__name__)
+
+
 def get_domain(request):
     """
     Return the current domain that the request is coming from,
@@ -355,3 +362,49 @@ def get_django_minified_image(url, **kwargs):
     resp = requests.get(url)
     new_image = resize_image(resp.content, **kwargs)
     return ImageFile(io.BytesIO(new_image), name="image.png")
+
+
+class CacheManager:
+    _cache = None
+    _cache_fallback = None
+
+    def __init__(self, *args, **kwargs):
+        BaseCache.__init__(self, *args, **kwargs)
+        self._cache = caches["main"]
+        self._cache_fallback = caches["fallback"]
+
+    def set(self, key, value, timeout=None):
+        if timeout is None:
+            timeout = self.default_timeout
+
+        try:
+            return self._cache.set(key, value, timeout)
+        except Exception as e:
+            logger.warning("Switching to fallback cache")
+            logger.exception(e)
+            return self._cache_fallback.set(key, value, timeout)
+
+    def get(self, key, default=None):
+        try:
+            return self._cache.get(key, default)
+        except Exception as e:
+            logger.warning("Switching to fallback cache")
+            logger.exception(e)
+            return self._cache_fallback.get(key, default)
+
+    def delete(self, key):
+        try:
+            return self._cache.delete(key)
+        except Exception as e:
+            logger.warning("Switching to fallback cache")
+            logger.exception(e)
+            return self._cache_fallback.delete(key)
+
+    def clear(self):
+        try:
+            return self._cache.clear()
+        except Exception as e:
+            logger.warning("Switching to fallback cache")
+            logger.exception(e)
+        finally:
+            self._cache_fallback.clear()

backend/pennclubs/settings/production.py

@@ -59,9 +59,17 @@
 # Caching settings
 CACHES = {
     "default": {
+        "BACKEND": "penn-clubs.backend.clubs.utils.CacheManager",
+        "TIMEOUT": 60 * 60,
+    },
+    "main": {
         "BACKEND": "django_redis.cache.RedisCache",
         "LOCATION": f"redis://{REDIS_HOST}:6379/1",
         "OPTIONS": {"CLIENT_CLASS": "django_redis.client.DefaultClient"},
         "KEY_PREFIX": "django",
-    }
+    },
+    "fallback": {
+        "BACKEND": "django.core.cache.backends.locmem.LocMemCache",
+        "LOCATION": "unique",
+    },
 }