Maybe I am not thinking clearly. If you assume that the client `could` be started from nginx, apache,  or another NodeJS server, then it is possible that the Zza App server is not running or (as you mentioned) that the Mongo Db is not running. So when I think of Client timeout-errors for Zza, either a) the App server is down or b) the Monbo Db server is not running.

Just an FYI.