Keep_alive is a parameter used to indicate if the platform has to leave the connection open to receive more
calls or not.
For example, if we are going to call a service repeatly in a program, the value of this variable has to be true.
Otherwise, if the service is going to be called only once the value has to be false.
In the case of call multiple times the same service with the parameter being false, the result will be that the
platform will open and close multiple connections, which is a bad practise.
The opposite is keep true a connection which is going to be called only once. In this case, the platform will close
the connection after a while, but is bad practise as well.
This parameter is set up when the callable object is created.
For more information about callable you can check this tutorial