I have a problem using “MQTT” protocol. I have a design to get and receive through this “MQTT” protocol to solve “NAT issue”(One of the best features of the MQTT is space decoupling, publisher and subscriber do not need to know each other - IP or any port number. They just know broker address)
This protocol is a proper way in the PFC.
I use “paho-mqtt” library of python2 in the Raspberry Pi/MacBook/Server(centos7). It is good to communicate with them. But, when I try publish file which size more than 25kb, I couldn’t subscribe!
I set a lot of scenario and testing to find what is problem origin. But I cant find what is problem.
Using broker on my server(Centos / public IP address)
1-1) Server (message broker)
1-2) Macbook(Publisher and Subscriber)
1-3) Raspberry PI(Publisher and Subscriber)
Above test case is fail when I trying file which has more than 25KB(If I trying file smaller than 20kb then success)
Using PublicBroker ( iot.eclipse.org)
2-0) iot.eclipse.org(message broker)
2-1) Server (Publisher and Subscriber)
2-2) Macbook(Publisher and Subscriber)
2-3) Raspberry PI(Publisher and Subscriber)
Above test is same, It failed when I trying file which has more than 25KB(If I trying file smaller than 20kb then success)
3-1) Macbook(message broker, localhost)
3-2) Macbook(publisher - process 1)
3-3) Macbook(subscriber - process 2)
Above tests are different. All test cases are successful. Even, I tried 1MB image file It success.( All of the test publish/subscribe is success).
I can’t narrow the origin of the problem. In addition, I read the MQTT message broker configuration and their community recommendation maximum file size. Default maximum size is 256MB.
If someone who has a experience or information is would really helpful to me!