What does "LIMITS for file descriptors changed" mean?

Question:

On a Unix system a message like "LIMITS for file descriptors changed to 128" may appear in the log file.

Answer:

This is not an error, and merely indicates that this Web Crossing activity is seeing a high number of simultaneous connections. Connections are increased 64 at a time, so this particular message just means that there were more than about 45 sockets in use (about 15 sockets are used for the database, stdin/out, etc.).