Hi, The proxy_cache_lock feature is nice to protect the backend server from being overloaded with requests. So we set that on and configure proxy_cache_lock_age to 20s, expecting the backend to be able to reply and send the request within that timeframe. By default the proxy_cache_lock_age is 5s By default the proxy_cache_lock_timeout is 5s With the age set to 20s, we expect requests toby Thijssss - Other discussion