We have a mongo server with ~140K collections. After restart or new node sync all file descriptors of all collections stay open, which is normal, what is abnormal is that the app suffered from a severe performance degradation until those FDs where closed. Is there any limitation regarding number of collections.
Another question: By default mongo closes FDs after 28hrs by default, except for the startup options `file_manager=(close_idle_time=300)` is there any "dynamic" parameter . we can use ?
Or maximum number of open files is 265000