From 5beeb0cc296626dff9a3c303b2120eea9fce98a2 Mon Sep 17 00:00:00 2001
From: Classic298 <27028174+Classic298@users.noreply.github.com>
Date: Thu, 5 Nov 2026 10:40:11 +0100
Subject: [PATCH] fix: every chat message fails on a Redis Cluster deployment
 (#33766)

With REDIS_CLUSTER enabled, every chat message failed with an error. The Redis connection recently added for terminal connections was used before it had read the cluster's layout. That connection now reads the layout first, so chats work again on a Redis Cluster. Plain Redis and Sentinel setups behave as before.

Fixes #33765
---
 backend/open_webui/utils/tether.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/backend/open_webui/utils/tether.py b/backend/open_webui/utils/tether.py
index 95b95ab3af..c42598724b 100644
--- a/backend/open_webui/utils/tether.py
+++ b/backend/open_webui/utils/tether.py
@@ -219,6 +219,8 @@ class Hub:
                 async_mode=True,
                 decode_responses=False,
             )
+            # RedisCluster can't route a pubsub subscribe until initialize() fills its slot cache.
+            await self.redis.initialize()
             pubsub = self.redis.pubsub()
             await pubsub.subscribe(self.channel(self.worker))
             self.listener = asyncio.create_task(self.listen(pubsub))