[mythtv-users] Adding a new frontend to an old mythtv system

[Phil Bridges]

The TL,DR version of this response, at least the last part, is "don't be a
dick".

On Apr 25, 2017 1:02 PM, "Joseph Fry" <joe at thefrys.com> wrote:

On Mon, Apr 24, 2017 at 8:13 PM Andrew <andrew_mythtv at 16paws.com> wrote:

> I have a suspicion that I know how this is going to go from the google
> searches that I've made, but I'm going to ask anyway because I find the
> expected answer hard to believe.
>
> I have a MythTV system that has been running for 6 or 7 years.  It
> consists of an x86 Debian backend server, with three HDHomeRuns, and a
> 9TB RAID5 fileserver, and one fanless SFF x86 Debian frontend tied to a
> big plasma.  The frontend tells me that it is release 0.23.1, so I
> assume the backend is the same vintage.  I happily use this as my ONLY
> HDTV viewing method, and have done so since 2010.  It works great.
>
> I am trying to add a new frontend box to the system, so I dutifully
> downloaded all the source (0.28), compiled (it took much longer than 30
> minutes, thank you very much) and ran through the wickets to install
> it.  Of course, it refuses to work with the old back end because, well,
> actually I can't think of a good "why".


I can think of several good reasons "why".  But I believe the biggest is
that 0.23 was still doing a lot of direct database access from the
frontend, and as new features are added the database changed and the
frontend needed to be updated to work with the new database schema.

Every version since then has placed more and more functionality behind an
API, which could eventually result in more flexibility since the API could
be written to allow frontends to communicate using various api versions to
allow backward compatibility.


> So that was a waste of time.  How does one get a new frontend
> forward/backward compatible with an older backend.  Please don't lecture
> me on the semantics of what is forward and what is backward because it
> is pointless and both apply depending if one is viewing the problem from
> the frontend or backend - I see that is the standard non-answer from the
> google searches I have made.
>

Newer frontends simply cannot work with older backends because maintaining
the legacy direct database access methodology was not in the best interest
of the project.  I'm not a developer or a decision maker, but I
wholeheartedly agree with the ongoing efforts to move to an API, even if
that means that I have to upgrade across the board.


> My constraints: no, I'm not deleting 9 TB of stored programs, nor am I
> interested in risking losing the database for over 1200 recorded
> programs.  No, I'm not interested in a solution that requires an entire
> system upgrade of every component simply to add a new one later.  In
> particular when any Linux upgrade means that you're likely to lose
> hardware graphics support because, well, fuck you, that's why.  Years of
> experience have taught me to never upgrade anything in a working Linux
> system because the result is a trail of tears until eventually the
> hardware is thrown out.  Not every Linux user is a college kid with a
> low end laptop, leaching free wifi at a coffee shop, with the attention
> span of a goldfish.
>

You make a lot of assumptions here that I suspect are a bit inflated.  No
upgrade would require the deletion of your stored programs, and while a
database backup is highly recommended, the upgrade should update the schema
from 0.23 just fine.

If your not interested in a solution that requires a full system upgrade to
introduce an updated client, then you might want to look at something other
than MythTV.  There is no backward compatibility in mythtv's components
right now and I suspect this will hold true for some time as I believe the
effort to move all client communications to the API is still ongoing.

I have been running MythTV on the same Ubuntu server build since 0.21
(database goes back to 0.16 IIRC).  I have upgraded both the OS and MythTV
every 6-12 months with very few issues.  And I'm not a college kid, and my
server is no low end laptop, and I pay for my own internet service.  Not
really sure what you were trying to suggest with those statements.


> How does the rest of the world work as expected when new frontend
> devices, let's call them "TV's", continue to be introduced supporting
> new features (NTSC, ATSC, QAM, IPTV, RS170, S Video, component, VGA RGB,
> HDMI) and yet they still work with older program sources?  It seems like
> an inherently reasonable model.
>

Your talking about standards compatibility between products whose standard
was developed by an international body of engineers, and implemented by
corporations investing millions in the technology.  MythTV doesn't use any
published standards other than it's own to communicate between the backend
and the frontend, it does not have a international standards body
developing a fixed standard that frontends will used to communicate with
backends, and it definitely doesn't have millions of dollars to pay
engineers to develop compatible equipment.

However, as previously stated, MythTV is gradually trying to force all
client communications to a standardized API, at which point we may finally
see some sort of "standard" that frontends could be written to support.


> My skills: 35 years software developer, three electrical and computer
> engineering degrees from a first tier engineering school, have
> used/developed on BSD Unix for 35 years and Linux for 10, and a dozen
> years writing drivers and firmware in the Silicon Valley.  So I'm not a
> noob, and yes I checked the FAQ, it was useless for me.
>

Sounds to me like you have the necessary skills to backup and perform an
upgrade of your system to allow it to run 0.28, which is what I would
recommend.


> How how can I add an new frontend to my current MythTV system?
>

You can't, unless your "new frontend" is running the old mythfrontend code
(which you may be able to download and compile).

In addition to the attempt to help with your technical issues, I would like
to address your approach to the community.  While the open source community
can be hit or miss when it comes to courtesy, it is never a good idea to
ask for help while simultaneously insulting the project or the members of
that community.  While I''m not certain that was your intent, your comments
about the nature of linux users (which are patently false), or the
suggestion that the decision to not allow backward compatibility is not
reasonable, not to mention your spouting your resume, certainly came across
as rude and arrogant.

I know there have been some solutions already presented, but I think that
you have already dismissed the best solution, and that is to bite the
bullet and upgrade your system.  If that is absolutely not going to happen,
then you may have some success compiling the 0.23 frontend from source,
finding an old .deb (https://launchpad.net/~mythbuntu/+archive/ubuntu/0.
23/+build/1926581), or even installing an old version of ubuntu/debian and
installing it from their repositories (might be less dependency hell than
trying to install on a newer distro).

But I would really consider upgrading, it will probably be somewhat
painful, but you can't honestly think that you will NEVER upgrade... you
have to draw the line somewhere and 7 years is a long time.



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