>> No well, written software won't spawn zombie-processes - sorry. > And yet it happens. Strange, I have been running software in docker for almost 2 years in

>> No well, written software won't spawn zombie-processes - sorry. > And yet it happens. Strange, I have been running software in docker for almost 2 years in production on 6 docker hosts running a ton of containers these days, and yes - a lot of this software spawns child-processes. In all this time I have never seen zombie processes with one major execption: Phusion Passenger to run our Redmine instance. If you run this under supervisord as 'init' process - you indeed notice the init process cleaning up "zombie processes" at startup like this: 2015-12-24 01:00:32,273 CRIT reaped unknown pid 600) 2015-12-24 01:00:34,774 CRIT reaped unknown pid 594) 2015-12-24 01:00:35,802 CRIT reaped unknown pid 610) So that case for me is the exception, and I do use an init process (supervisord) to run only apache with passenger. Note that using Apache with PHP or plain does not leak zombie processes.