How to change MongoDB slowOpThresholdMs in mongo shell I need to decrease the slowms trash hold to 50, can't find the way of doing that without restarting the mongod process.
The slowOpThresholdMs setting defines what constitutes a “slow” operation. To set the threshold which the profiler considers operations “slow” (and thus, included in the level 1 profiling data), you can configure slowOpThresholdMs at runtime as an argument to the db.setProfilingLevel() operation. 

For Ref setProfilingLevel and 
slowOpThresholdMs

Note:  The threshold for slow operations applies to the entire mongod instance. When you change the threshold, you change it for all databases on the instance.

For Example:

{ profile: 1, slowms: 200 }


Database profiling can impact database performance. Enable this option only after careful consideration