[wildfly-dev] Wildfly start-up as service script depends on console log to determinate start result

[Jason T. Greene]

> On Jun 10, 2015, at 11:46 AM, Brian Stansberry <brian.stansberry at redhat.com> wrote:
> 
> So, what purpose is this fulfilling?
> 
> 2) How does other software solve this problem? If it's solving a valid 
> problem, it seems like there would be a typical solution.

The classic UNIX solution is that the daemon forks and returns, dropping a PID file of its child to disk, after it is done initializing and exits with an error code when there is a problem.

Systemd added other approaches, where a daemon can signal systemd directly, or it can use dbus to send a message.

The former can't be done efficiently in Java because it doesn't have a pure fork(), only an exec. Although it would be possible to emulate with an exec with an unacceptable hit to boot time. The latter options are too Linux specific.

I think the best solution would be for us to add a signaling mechanism specifically for this purpose. We could use sun.misc.Signal (potentially an issue on Java 9), or we could exec the kill command to signal a process. 

We could also use a specially status file (e.g standalone.sh --start-status-file=blah) for a script to monitor.

Thoughts?