Am I the only person that doesn't want logging to block or buffer? Streams are great until you realize that when the thing that you are piping stdout to blocks then your program goes to sleep too... all because something couldn't process your debug logs? Files have the same problem... no space left on device, so all your apps have to crash!?

Using non-blocking IO is a solution, but then when the fd is unwritable for a while, you buffer data and your machine runs out of memory. So also not good.

I'm a big fan of the strategy Varnish uses. It mmaps a block of memory, and then treats it as a ring buffer. A separate program can connect to this and read the logs to a file or a pipe, but if that program fails, you don't stop serving web pages. As long as allocated memory doesn't randomly disappear and the Universe doesn't implode, logging adds no overhead or risk of failure to your app.

Logs are essential, but I don't necessarily want a failure in the logging system to break my app. When you use files or pipes, you run this risk.