A customer called with an emergency issue: A server that normally runs many MySQL instances wouldn’t start them up. Not only would it not start all of them, it wouldn’t even start the first one. The multiple instances were started through the mysql_multi init script. Perhaps you already know what was wrong!
This is the third in a series on what’s seriously limiting MySQL in core use cases (links: part 1, 2, 3). This post is about the way MySQL handles connections, allocating one thread per connection to the server.