if you want to try really something else then you have to use 2waysocket (the rest are the same thing in a bit different configurations)
the thing is that rmi connections that are idle, so not used anymore should be removed by the "rmi.connection.timeout" setting we have on the admin page.
thats default i think 120 seconds but even if i lower that to 12 seconds it doesn't seem to help for me locally
In 7.4 you did use also Http&Socket or just Socket?