Reliable process tracking

[Edward Tomasz Napierała]

Wiadomość napisana przez Alfred Perlstein <alfred at FreeBSD.org> w dniu 5 sie 2013, o godz. 05:44:
> On 8/4/13 9:49 AM, Jilles Tjoelker wrote:
>> On Sun, Aug 04, 2013 at 10:27:08AM -0400, Tom Rhodes wrote:
>>> On Sun, 4 Aug 2013 15:46:58 +0200
>>> Jilles Tjoelker <jilles at stack.nl> wrote:
>>>> When shutting down a service or requesting status, rc.subr currently
>>>> uses a combination of pidfiles and process names. This is fairly but not
>>>> completely reliable once it is set up correctly (which can take a lot of
>>>> work and possibly patching the daemon to use pidfile(3) from our
>>>> libutil). It is also incapable of killing multiprocess daemons such as
>>>> CGI web servers without cooperation of the daemon.
>>>> I think what is needed here is a facility that marks a process and all
>>>> of its descendants. Removing the mark should be a privileged or at least
>>>> an unusual operation; no unprivileged function specified by POSIX such
>>>> as setsid() should do this.
>>>> [snip]
>>>> Similar facilities in other operating systems: Linux cgroups, Solaris
>>>> process contracts.
>>> There is fscd - it does a lot of what you ask for.  In fact, I had
>>> talked to a few people about bringing it into base but have not
>>> really figured out how I want to integrate it into rc.
>> I think fscd complements reliable process tracking; it does not provide
>> it. Fscd relies on rc.d's status, stop and restart to work and therefore
>> only works properly if those work properly.
>> 
> Jilles, very exciting you are looking into this.  Have you evaluated Linux's "cgroup" facility?  From what I understand, it is a superset of your needs, so maybe taking some parts of it may help?

The good parts of cgroups were already implemented as setloginclass(2) :-)