fix: start tracking keys set by us immediately

frappe/tests/test_client_cache.py

@@ -31,7 +31,9 @@ class TestClientCache(IntegrationTestCase):
 		# frappe.cache is our "another client"
 		val = frappe.generate_hash()
 		frappe.cache.set_value(TEST_KEY, val)
-		time.sleep(0.5)
+		# This is almost instant, but obviously not as fast as running the next instruction in
+		# current thread. So we wait.
+		time.sleep(0.1)
 
 		with self.assertRedisCallCounts(1):
 			self.assertEqual(frappe.client_cache.get_value(TEST_KEY), val)

frappe/utils/redis_wrapper.py

@@ -462,6 +462,12 @@ class _ClientCache:
 		key = self.redis.make_key(key)
 		self.redis.set_value(key, val, shared=True)
 		self.local_cache[key] = (val, time.monotonic() + self.local_ttl)
+		# XXX: We need to tell redis that we indeed read this key we just wrote
+		# This is an edge case:
+		# - Client A writes a key and reads it again from local cache
+		# - Client B overwrites this key, but since client A never "read" it from Redis, Redis
+		#   doesn't send invalidation.
+		_ = self.redis.get_value(key, shared=True, use_local_cache=False)
 
 	def delete_value(self, key):
 		key = self.redis.make_key(key)