I've found a number of articles describing how to increase the limits for the number of open files through /etc/security/limits.conf, but I don't understand the impact of doing so. Many times I see people updating 1024 to 2048. Ok, those file handles must cost RAM or something. Why not increase it to 100000? What resource am I eating up with open files?
A question about how to increase the limits: https://stackoverflow.com/questions/34588/how-do-i-change-the-number-of-open-files-limit-in-linux