This KB describes a scenario in which traffic drops may be seen when scheduler parameters (transmit-rate, buffer-size, and priority) are changed with traffic flowing.
This issue might be seen if the following conditions are met:
On Junos ACX710 when scheduler parameters (transmit-rate, buffer-size, and priority) are changed with traffic flowing, it may result in continuous drops for the VOQs (Virtual output queue) associated with the interface and the CoS profile that was changed when the traffic is way lower than the port bandwidth.
All the VOQs associated with the CoS profile (scheduler) will be affected.
The 'show interfaces queue egress <interfaces>' command can be used to check the RED (Random Early Detection) drops.
In order to avoid traffic drop due to above mentioned parameters changes,the traffic needs to be drained off/stopped when changing CoS scheduler parameters (transmit-rate, buffer-size, and priority).