[mythtv-users] SystemD (Was: Recommended Linux Distro post CentOS)

[R. G. Newbury]

On 2020-12-25 4:21 p.m., marcus hall wrote:
> On Fri, Dec 25, 2020 at 01:24:40PM -0500, R. G. Newbury wrote:
>>
>> I hope we have not confused the OP. Not a misconception on my part. I was
>> talking about setting up an external FE. As you point out, the database
>> server *can be* on a different box entirely from any BE or FE. In that case,
>> all boxes are treated as 'external' to the db server and need the <Host>
>> attribute to point to the db box. Only in the case of a combined BE/db
>> server can you use (and should use) 'localhost' (so that, in that particular
>> case, a socket is used instead of networking).
> 
> Not confused at all, I just was expressing exasperation at systemd, not really
> looking for anything.  > I did add StartLimitIntervalSec = 0 to my override file
> and next time things reboot, perhaps the backend will start up.
> 
> It does so happen that the database and one frontend are on the same box, but
> nowadays I tend to use other frontends more than it.

Ah HAH! You have the db server and an FE on one box. So where is the BE? 
If it is on another box, then quite possibly your BE box cannot access 
the dbserver and (drum-roll....) the BE will not start.
If the BE is on the same box with the db server (and an FE) there is 
still the possibility that the BE 'user' is not properly authenticated 
to the mariadb server.

I find it difficult to express with appropriate moderation my 
disagreement with the proposition

https://lists.archive.carbon60.com/mythtv/users/214422?search_string=mandamus.org%20mysql;#214422

This link does "baby steps" through ensuring that your computers can 
talk to the db server. In going through that test procedure you will 
have to start on the db server to check that you can access it properly. 
Then run the mc.sql script once for each user+computer combo to set up 
the database accesses. Then you can check on the dbserver (as root) 
using the mysql database with: 'select host, user, password from user;' 
(Yes there is a field named user in a table named user.) That should 
list each computer and each user on that computer. If the BE is on a 
separate box, it needs that access too.

As you go around and try from each computer with each user/computer 
combo you do NOT want to see 'Access denied to 'luser'@'some-computer' 
but if you do, you know what needs to be fixed.

Until you are absolutely sure that each mythtv user can access the db 
server from its own box, it is useless to try starting the BE.

>  I am anticipating
> retiring that box and building a container for it on my main server (or
> maybe just running it native, I don't have any exposure to the outside world
> on any mythtv ports).

> It does seem like with restarts every 3 seconds, It seems that I could hit
> the StartLimit of 5 restarts at 12 seconds, after the default of 10s, but
> maybe that is slightly too close, although it seemed to fail startup for
> 3 of 3 reboots since the problem started happening...

I now strongly suspect that the BE cannot access the db server. Have you 
tried starting the BE from a console? You should be able to see the 
exact error(s) and that completely removes the systemctl startup script 
from consideration.

Geoff