View count diverges between systems
Review this Python function that increments a counter cached in Redis backed by Postgres.
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0:00 of about 26 min
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1def increment_views(redis, db, post_id):
2 cached = redis.get(f"views:{post_id}")
3 if cached is None:
4 row = db.execute(
5 "SELECT views FROM posts WHERE id = %s", (post_id,)
6 ).fetchone()
7 cached = row[0]
8 new_val = int(cached) + 1
9 redis.set(f"views:{post_id}", new_val)
10 db.execute("UPDATE posts SET views = %s WHERE id = %s", (new_val, post_id))
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