The recent emerging concept in the networking world is known as SDN (Software-Defined Network). SDN architecture introduced the new methods of network management and configuration. It makes underlying networking devices as simply just packet forwarding units and leaving the control logic on centralized software program to dictate the entire network behavior. In logically centralized SDN architecture the switches are statically assigned to controllers regardless of actual load of individual controllers. One of the key concern of network operators is to efficiently monitor the actual load of individual controllers in a logically centralized SDN environment. In this paper, we propose an adaptive solution to monitor the actual load of a SDN controller for efficient utilization in a logically centralized SDN architecture. We proposed a load monitoring solution which is combination of ONOS (Open Network Operating System) based collection manager and collectd based “onos write” plugin/module that act as an agent on SDN controllers. Our proposed solution helps to overcome the under-utilization and over-utilization of a controller implemented in logically centralized SDN environment. The results show that our proposed monitoring system gives a comprehensive statistical view of individual controller's load.