Revert "Bug 1851253 - store new failure lines in database for persist…

…ent storage across reboots. (#7818)"

This reverts commit 1310f34.

initialize_data.sh

@@ -12,6 +12,4 @@ if [ "${DATABASE_URL}" == "mysql://root@mysql/treeherder" ] ||
     ./manage.py load_initial_data
 fi
 
-./manage.py createcachetable
-
 exec "$@"

tests/test_setup.py

@@ -1,7 +1,7 @@
 import pytest
 import responses
 from celery import current_app
-from django.core.cache import caches
+from django.core.cache import cache
 from django.core.management import call_command
 
 from treeherder.utils.http import fetch_text
@@ -26,18 +26,12 @@ def test_no_missing_migrations():
     call_command('makemigrations', interactive=False, dry_run=True, check_changes=True)
 
 
-@pytest.mark.django_db
 def test_django_cache():
     """Test the Django cache backend & associated server are properly set up."""
     k, v = 'my_key', 'my_value'
-    cache = caches['default']
     cache.set(k, v, 10)
     assert cache.get(k) == v
 
-    db_cache = caches['db_cache']
-    db_cache.set(k, v, 10)
-    assert db_cache.get(k) == v
-
 
 @current_app.task
 def add(x, y):

treeherder/config/settings.py

@@ -182,10 +182,6 @@
             'SOCKET_CONNECT_TIMEOUT': 5,
         },
     },
-    'db_cache': {
-        "BACKEND": "django.core.cache.backends.db.DatabaseCache",
-        "LOCATION": "new_failure_cache",
-    },
 }
 
 # Internationalization

treeherder/model/error_summary.py

@@ -3,7 +3,7 @@
 import re
 import newrelic.agent
 
-from django.core.cache import caches
+from django.core.cache import cache
 
 from treeherder.model.models import Bugscache, TextLogError
 
@@ -15,8 +15,6 @@
 BUG_SUGGESTION_CACHE_TIMEOUT = 86400
 LINE_CACHE_TIMEOUT_DAYS = 21
 LINE_CACHE_TIMEOUT = 86400 * LINE_CACHE_TIMEOUT_DAYS
-db_cache = caches['db_cache']
-cache = caches['default']
 
 LEAK_RE = re.compile(r'\d+ bytes leaked \((.+)\)$|leak at (.+)$')
 CRASH_RE = re.compile(r'.+ application crashed \[@ (.+)\] \|.+')
@@ -43,7 +41,7 @@ def get_error_summary(job, queryset=None):
     line_cache_key = 'mc_error_lines'
     if job.repository == "comm-central":
         line_cache_key = 'cc_error_lines'
-    line_cache = db_cache.get(line_cache_key)
+    line_cache = cache.get(line_cache_key)
     if line_cache is None:
         line_cache = {str(job.submit_time.date()): {}}
     else:
@@ -85,7 +83,7 @@ def get_error_summary(job, queryset=None):
         logger.error('error caching error_summary for job %s: %s', job.id, e, exc_info=True)
 
     try:
-        db_cache.set(line_cache_key, line_cache, LINE_CACHE_TIMEOUT)
+        cache.set(line_cache_key, line_cache, LINE_CACHE_TIMEOUT)
     except Exception as e:
         newrelic.agent.record_custom_event('error caching error_lines for job', job.id)
         logger.error('error caching error_lines for job %s: %s', job.id, e, exc_info=True)

treeherder/webapp/api/note.py

@@ -1,4 +1,4 @@
-from django.core.cache import caches
+from django.core.cache import cache
 
 from rest_framework import viewsets
 from rest_framework.decorators import action
@@ -92,9 +92,8 @@ def create(self, request, project):
 
         if fc_id == 2:  # this is for fixed_by_commit (backout | follow_up_commit)
             # remove cached failure line counts
-            db_cache = caches['db_cache']
             line_cache_key = 'error_lines'
-            line_cache = db_cache.get(line_cache_key)
+            line_cache = cache.get(line_cache_key)
             date = current_job.submit_time.date().isoformat()
             if line_cache and date in line_cache.keys():
                 for err in TextLogError.objects.filter(job=current_job):
@@ -108,7 +107,7 @@ def create(self, request, project):
                         ):
                             del line_cache[date]["new_lines"][cache_clean_line]
                         try:
-                            db_cache.set(line_cache_key, line_cache, LINE_CACHE_TIMEOUT)
+                            cache.set(line_cache_key, line_cache, LINE_CACHE_TIMEOUT)
                         except Exception as e:
                             logger.error(
                                 'error caching error_lines for job %s: %s',