use cache locks

feeds/admin.py

@@ -7,7 +7,7 @@ from feeds.modules import EchoFeedModuleConfig, DankMemesFeedModuleConfig, Shitt
 
 @admin.register(Feed)
 class FeedAdmin(admin.ModelAdmin):
-    list_display = '__str__', 'lock',
+    list_display = '__str__', 'locked',
 
 
 admin.site.register(EchoFeedModuleConfig)

feeds/migrations/0007_remove_feed_lock.py

@@ -0,0 +1,17 @@
+# Generated by Django 2.1.5 on 2019-11-24 14:07
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('feeds', '0006_tapasfeedmoduleconfig'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='feed',
+            name='lock',
+        ),
+    ]

feeds/models.py

@@ -1,6 +1,7 @@
 from django.conf import settings
 from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
 from django.contrib.contenttypes.models import ContentType
+from django.core.cache import cache
 from django.db import models
 from django.utils import timezone
 from telebot import TeleBot
@@ -16,20 +17,26 @@ class Feed(models.Model):
     check_interval = models.DurationField(help_text='in seconds')
     last_check = models.DateTimeField(null=True, blank=True)
     last_id = YAMLField(null=True, blank=True)
-    lock = models.BooleanField(default=False)
 
     config_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
     config_id = models.PositiveIntegerField()
     config = GenericForeignKey('config_type', 'config_id')
 
+    @property
+    def lock_key(self):
+        return 'feed-{}-lock'.format(self.pk)
+
+    @property
+    def locked(self):
+        return bool(cache.get(self.lock_key))
+
     def run_check(self):
-        if self.lock:
+        if self.locked:
             return False
         if self.last_check and timezone.now() < self.last_check + self.check_interval:
             return False
 
-        self.lock = True
-        self.save()
+        cache.set(self.lock_key, 1, timeout=60)
         execute_feed.apply_async(args=(self.pk,), shadow=str(self))
         return True
 

feeds/tasks.py

@@ -1,9 +1,9 @@
 import traceback
 
 import sentry_sdk
-from celery.exceptions import Reject
 from celery_once import QueueOnce
 from django.utils import timezone
+from django.core.cache import cache
 from telebot import TeleBot
 from djconfig import config
 
@@ -14,7 +14,7 @@ from config.celery import app
 def check_feeds():
     from feeds.models import Feed
 
-    feeds = Feed.objects.filter(lock=False)
+    feeds = Feed.objects.all()
     enqueued = []
     for feed in feeds:
         if feed.run_check():
@@ -47,5 +47,4 @@ def execute_feed(feed_pk):
             traceback.print_exc()
         finally:
             if feed:
-                feed.lock = False
-                feed.save()
+                cache.delete(feed.lock_key)