In my previous post Memory Management I was talking about storing character and room data in server memory.

For the Character memory management I basically just use a DateTime value that gets updated each time a request is made by the connected player. If the DateTime exceeds a certain limit such as 20 minutes then the character data is saved and removed from memory. If the player just has a long pause between requests their character data will be reloaded if they make another request after the cleanup.

For the Room or Place data I've though about doing the same thing, just store a DateTime value and update it whenever a player performs an action in the room. I am not sure this is the best approach since the only commands that reference the Place object are movement, looking, some inventory and buying commands. Other actions such as casting spells, viewing stats, private chat, etc. do not reference the Place object. Of course, I guess if you are not accessing the Place object no need to have it in memory but once a player attempts to move again I would need to reload the Place. I might just maintain a list in the Place object of all the players currently located there and only remove the object once those references have been removed. I'll try a few things and record what I find.