My application was running fine since jun/27, and yesterday the remove() method became really slow

I'm using an i2.8xlarge in AWS

I tried to shutdown the service (db.stepDown() followed by db.shutdownServer()), and after 50 minutes it didn't shut down, I had to kill -9 <PID> to stop the process and reopen it, after restarting the service, the problem disappeared

I can provide the diagnotics folder and db.currentOp() output when the slowness was happening