In firedrill it cause all three instance hang when :8046 be killed

[dlintw]

https://github.com/ha/doozerd/blob/master/doc/firedrill.md

If the first process be killed, all three dockerd are stopped.
doozerd -timeout 5 -l 127.0.0.1:8046 -w 127.0.0.1:8000 2>/dev/null &