mongo clients can override some parameters (e.g "no cursor timeout") resulting in uncontrollable outcomes.

Example :
DB perf. can be impacted if the number of opened cursors reaches 4k, this is caused by setting "no cursor timeout" on the client side, unfortunately the later override current value in DB servers

Due to mongo limitations we cannot prevent a client (via a driver) to override the current server setting (including open/close explicit cursors), the alternative we have adopted for now is to alert & detect:

1- Setup an alert for all parameters susceptible of causing perf. issues in DB
Note: Alert(s) thresholds have been revised and values have been lowered in order to have enough room for action | e.g cursor threshold is 50

2- Isolate offending clients by providing IP address and checking for any driver config update (DBA > through logs and/or mongo shell commands)

The option cited above (#1 & #2) is just a temporary measure as we would like to see more flexibility from the DB and back end side.