Everytime I regenerate a lot in the empire, there is some lag. The server also uses more memory which does not reset. If the max memory is used, I need to restart it. When I regenerate a lot in the skylands, the lag is so heavy that it might boot everyone off the server. And the memory used is so much that I need to restart the server after every two lots that I reset. You can imagine that this is not the most popular job in the world.
So first I started to reset one lot each day. I got fed up with this however and decided to try something else and started a parallel server with less memory, copied the skylands over and reset it over there. I was able to do resets without causing lag on the main server but had to restart the parallel server after every lot. After 3 hours finally I could reset all the lots in the skylands that were abandoned along with all the faulty chunks that were generated some time in the past and looked like normal world chunks. Then I shut down the main server and copied the new skylands back. Now I am running a full map-rendering process for the 3D map. The 2D map will render on schedule in about 12 hours anyhow.
If i keep up from now on with the abandoned lots there should be no more problem. I also had a new Skylands generator version installed and the new environment looks much nicer than the old one, with more trees etc. Also, we now got rid of the “absent since 300” users that were only still in the users list due to the fact that they still had a lot in the skylands.