Table.1

The above table shows results of load test performed using MQTT. Following is the test bed that has been used.

Device: Raspberrypi 2

Broker: Mosquitto

Load test software: MqttBox

From table we infer that lesser is the QoS (Quality of Service) higher is the CPU utilization and higher is the QoS (QoS2) lesser is the CPU utilization. Irrespective of the number of messages. In the load test performed maximum of 1 lakh messages was to be published were each message is of size 2 Bytes out of which only 35,496 messages were published and rest of the messages were lost as the session timed out. The CPU consumption for 1 lakh messages was 4.7%. Similarly, 100 messages were to be published out of which all 100 was published were each message was of size 2 Bytes. The CPU utilization was 0.3%. Based on size of file CPU utilization tends to vary. Based on the analysis CPU utilization is less in MQTT when compared with other communication protocols.