Deep Reflections

This is a story of multiple processes running on a system, but with empty PID files.

It took a lot of debugging.

Can you tell me when a shell sends a “HANGUP” signal to a process? What happens if there is a pipeline? What if you prefix this pipeline with the “nohup” command?

If you don’t do log rotation right, you may have a full hard drive and a ghost file.

Have you run into a problem that happens only once in a while, and you never seem to have enough information to figure it out? We all have. This is one such tale: except that it has a happier ending.

As programmers, we face it many times: a build fails on only our system. This is one such tale.

This is a tale about a hopelessly bad error message.