I have been using MQTT to transfer the information between the server and multiple remote devices. I am using paho mqtt library for my server side ( Raspberry PI) which is capable of transmitting a message using QOS which ensures that the message will be sent. However, sending a message with QOS does not do any good if a receiver does not support QOS as well which is the case for the PubSubClient.
The more testing I did for my program I have noticed that I keep missing a message every now and then and It lead me to believe that it might be caused due to the PubSubClient not being able to publish/receive a message with QOS.
Have anyone else worked with this library and have found simmilar problems? Are there any ways to overcome this?
However, sending a message with QOS does not do any good if a receiver does not support QOS as well which is the case for the PubSubClient.
Sure, but which part is the sender and which is the receiver. If you publish a message and set a QOS higher than 0 this does only influence the connection between you and the MQTT broker (server). It has no influence on the subscribers!
PubSubClient supports QOS for subscriptions but not for publishing. Feel free to extend the library to support it for publishing too and provide patch to the maintainer.
Reading your post I get the impression you didn't understand the concept of QOS as used in MQTT. This is a site that describes the usage in detail and is easy to understand.