Check the error log for clues. If that doesn't reveal anything, set up a script (using cron or Task Scheduler)...
to attempt to log in every few minutes during the night, to see if there is a consistent time of failure. Look for any other scheduled tasks that might occur around the same time -- DNS refresh, system backups, etc.
Related Q&A from Scott Noyes
Get suggestions for choosing MySQL character sets and field collations from expert Scott Noyes.continue reading
A MySQL expert describes two ways that the multi-master support can be used.continue reading
An expert describes where to find information on detection deadlock algorithms in MySQL.continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.