DB caching reuses the same id field

Author: sdarwin

config/settings.py

@@ -282,6 +282,8 @@
 }
 CELERY_RESULT_BACKEND_THREAD_SAFE = True
 CELERY_TASK_ALWAYS_EAGER = env("CELERY_TASK_ALWAYS_EAGER", False)
+# Reduce large amount of logging in redis. Default 1 day.
+CELERY_TASK_RESULT_EXPIRES = 3600
 
 CACHES = {
     "default": {
@@ -300,7 +302,9 @@
 ENABLE_DB_CACHE = env.bool("ENABLE_DB_CACHE", default=False)
 
 # Default interval by which to clear the static content cache
-CLEAR_STATIC_CONTENT_CACHE_DAYS = 7
+# New method: "never" clear, just overwrite, so that the id
+# field doesn't expand without bounds.
+CLEAR_STATIC_CONTENT_CACHE_DAYS = 7000
 
 # Hyperkitty
 HYPERKITTY_DATABASE_NAME = env("HYPERKITTY_DATABASE_NAME", default="")

core/views.py

@@ -1,5 +1,7 @@
 import os
 import re
+from django.utils import timezone
+
 from urllib.parse import urljoin
 
 import requests
@@ -335,8 +337,17 @@ def get_from_cache(self, static_content_cache, cache_key):
         return cached_result if cached_result else None
 
     def get_from_database(self, cache_key):
+        rendered_content_cache_time = 2628288
+        dev_docs = ["static_content_develop/", "static_content_master/"]
+        for substring in dev_docs:
+            if substring in cache_key:
+                rendered_content_cache_time = 120  # Switch this to 3600
+        now = timezone.now()
+        start_time = now - timezone.timedelta(seconds=rendered_content_cache_time)
         try:
-            content_obj = RenderedContent.objects.get(cache_key=cache_key)
+            content_obj = RenderedContent.objects.filter(modified__gte=start_time).get(
+                cache_key=cache_key
+            )
             return {
                 "content": content_obj.content_html,
                 "content_type": content_obj.content_type,