feat: add redis fallback mechanism #21043 (#21044)

Co-authored-by: tech <cto@sb>
Co-authored-by: crazywoola <100913391+crazywoola@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

api/extensions/ext_redis.py

@@ -1,6 +1,10 @@
+import functools
+import logging
+from collections.abc import Callable
 from typing import Any, Union
 
 import redis
+from redis import RedisError
 from redis.cache import CacheConfig
 from redis.cluster import ClusterNode, RedisCluster
 from redis.connection import Connection, SSLConnection
@@ -9,6 +13,8 @@ from redis.sentinel import Sentinel
 from configs import dify_config
 from dify_app import DifyApp
 
+logger = logging.getLogger(__name__)
+
 
 class RedisClientWrapper:
     """
@@ -115,3 +121,25 @@ def init_app(app: DifyApp):
         redis_client.initialize(redis.Redis(connection_pool=pool))
 
     app.extensions["redis"] = redis_client
+
+
+def redis_fallback(default_return: Any = None):
+    """
+    decorator to handle Redis operation exceptions and return a default value when Redis is unavailable.
+
+    Args:
+        default_return: The value to return when a Redis operation fails. Defaults to None.
+    """
+
+    def decorator(func: Callable):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            try:
+                return func(*args, **kwargs)
+            except RedisError as e:
+                logger.warning(f"Redis operation failed in {func.__name__}: {str(e)}", exc_info=True)
+                return default_return
+
+        return wrapper
+
+    return decorator

api/services/account_service.py

@@ -16,7 +16,7 @@ from configs import dify_config
 from constants.languages import language_timezone_mapping, languages
 from events.tenant_event import tenant_was_created
 from extensions.ext_database import db
-from extensions.ext_redis import redis_client
+from extensions.ext_redis import redis_client, redis_fallback
 from libs.helper import RateLimiter, TokenManager
 from libs.passport import PassportService
 from libs.password import compare_password, hash_password, valid_password
@@ -495,6 +495,7 @@ class AccountService:
         return account
 
     @staticmethod
+    @redis_fallback(default_return=None)
     def add_login_error_rate_limit(email: str) -> None:
         key = f"login_error_rate_limit:{email}"
         count = redis_client.get(key)
@@ -504,6 +505,7 @@ class AccountService:
         redis_client.setex(key, dify_config.LOGIN_LOCKOUT_DURATION, count)
 
     @staticmethod
+    @redis_fallback(default_return=False)
     def is_login_error_rate_limit(email: str) -> bool:
         key = f"login_error_rate_limit:{email}"
         count = redis_client.get(key)
@@ -516,11 +518,13 @@ class AccountService:
         return False
 
     @staticmethod
+    @redis_fallback(default_return=None)
     def reset_login_error_rate_limit(email: str):
         key = f"login_error_rate_limit:{email}"
         redis_client.delete(key)
 
     @staticmethod
+    @redis_fallback(default_return=None)
     def add_forgot_password_error_rate_limit(email: str) -> None:
         key = f"forgot_password_error_rate_limit:{email}"
         count = redis_client.get(key)
@@ -530,6 +534,7 @@ class AccountService:
         redis_client.setex(key, dify_config.FORGOT_PASSWORD_LOCKOUT_DURATION, count)
 
     @staticmethod
+    @redis_fallback(default_return=False)
     def is_forgot_password_error_rate_limit(email: str) -> bool:
         key = f"forgot_password_error_rate_limit:{email}"
         count = redis_client.get(key)
@@ -542,11 +547,13 @@ class AccountService:
         return False
 
     @staticmethod
+    @redis_fallback(default_return=None)
     def reset_forgot_password_error_rate_limit(email: str):
         key = f"forgot_password_error_rate_limit:{email}"
         redis_client.delete(key)
 
     @staticmethod
+    @redis_fallback(default_return=False)
     def is_email_send_ip_limit(ip_address: str):
         minute_key = f"email_send_ip_limit_minute:{ip_address}"
         freeze_key = f"email_send_ip_limit_freeze:{ip_address}"

api/tests/unit_tests/extensions/test_redis.py

@@ -0,0 +1,53 @@
+from redis import RedisError
+
+from extensions.ext_redis import redis_fallback
+
+
+def test_redis_fallback_success():
+    @redis_fallback(default_return=None)
+    def test_func():
+        return "success"
+
+    assert test_func() == "success"
+
+
+def test_redis_fallback_error():
+    @redis_fallback(default_return="fallback")
+    def test_func():
+        raise RedisError("Redis error")
+
+    assert test_func() == "fallback"
+
+
+def test_redis_fallback_none_default():
+    @redis_fallback()
+    def test_func():
+        raise RedisError("Redis error")
+
+    assert test_func() is None
+
+
+def test_redis_fallback_with_args():
+    @redis_fallback(default_return=0)
+    def test_func(x, y):
+        raise RedisError("Redis error")
+
+    assert test_func(1, 2) == 0
+
+
+def test_redis_fallback_with_kwargs():
+    @redis_fallback(default_return={})
+    def test_func(x=None, y=None):
+        raise RedisError("Redis error")
+
+    assert test_func(x=1, y=2) == {}
+
+
+def test_redis_fallback_preserves_function_metadata():
+    @redis_fallback(default_return=None)
+    def test_func():
+        """Test function docstring"""
+        pass
+
+    assert test_func.__name__ == "test_func"
+    assert test_func.__doc__ == "Test function docstring"