On Fri, Oct 27, 2017 at 7:57 PM, ToddAndMargo <[log in to unmask]> wrote:
>>> On Fri, Oct 27, 2017 at 3:57 PM, ToddAndMargo <[log in to unmask]
>>> <mailto:[log in to unmask]>> wrote:
>>>
>>>     Dear List,
>>>
>>>     In the situation I am facing, a database is not shutdown by the
>>>     systemd script that started it at boot. (Its start point was
>>>     actually hacked into a related bash file called by another
>>>     systems script without a shutdown hack.)  There is no "ExecStop"
>>>     line.   NO, IT WAS NO  MY DOING !!!
>>>
>>>     I am not saying which (proprietary) database as I don’t want to
>>>     get into any legal cross hairs.  Anyway, someone else is using
>>>     the database.  The database works fine.
>>>
>>>     The vendor is not systemd literate and keeps complaining about
>>>     it only works under SysV.  And no, they won’t give me the SysV
>>>     rc.d scripts and let me convert it for them.  And, yes, I know,
>>>     you can still use SysV if you must.  But, again, as I said,
>>>     it is not my doing.
>>>
>>>     I am thinking there is a possibility of data corruptions.
>>>
>>>     Question: does the general shutdown take care of this issue?
>>>     Am I presuming too much to think this is handled by the general
>>>     shutdown global SIGTERM?  The database does properly respond
>>>     to SIGTERM.
>>>
>>>     Do I understand the global SIGTERM correctly?
>>>
>>>     Many thanks,
>>>     -T
>>>
>>>
>
> On 10/27/2017 02:31 PM, Paul Robert Marino wrote:
>>
>> you understand the global sigterm correctly but there is a problem with
>> relying on that. while it is true that a global sigterm is issued it is
>> followed shortly afterward by a global kill. what that means is it may not
>> give the database sufficient time to shutdown before killing it. whenever
>> databases are involved you can not count on the global sigterm to shut it
>> down correctly in time
>>
>
> Hi Paul,
>
> Now I understand.  Thank you!
>
> I was wondering why one would go through all the effort
> to do a "ExecStop" in systemd if shutdown was going to send
> SIGTERM to everyone anyway.  Well because the process might
> not have long enough to shutdown before the SIGKILL or have
> all its sub process complete properly either.

I've run into similar shutdown delay issues with MySQ under systemd,
and worse ones with tomcat. (Tomcat init scripts and systemd tools are
wrappers for catalina.sh, which is a SysV init script and not a very
good one.)