I'd like to try to set up a minimyth frontend for use with my
KM 5.5 backend, but I can't figure out if I'm going to have
protocol version mismatch issues.

What protocol version is R5.5 using? I don't see it mentioned
anywhere in the changelog.

Do all changes to the protocol protocol version number indicate
incompatibility, or are some changes backward compatible?

Minimyth currently has two versions of Myth available:

0.20.2 (changeset 16082)

0.21.0 (changeset 19778)

If I'm reading http://www.mythtv.org/wiki/Myth_Protocol
correctly, changeset 16082 is using protocol version 39, and
changeset 19778 is using an unknown protocol number >= 42.

The only thing I can find in KM that looks like it might be a
changeset number is

Source code version : 14463M

It looks like changeset 14463 is using protocol version 35.

I presume I've got a better chance of compatibility with KM
R5.5 using 0.20.2 than using 0.21.0. But, 35 != 39, and it
would be nice to know if 0.20.2 was going to be compatible
before I go to the trouble of setting up the FE box.

Is MythTv's protocol versioning as big a mess as it appears? It
looks like it's simply not reasonable to expect to run a
frontend and backend that weren't build from exactly the same
source tree. Yet users of MiniMyth must be using _something_
else as a backend, since MiniMyth was traditionally a FE-only
distro (recently it's included slave-BE abilities).

_________________
Grant

No Recommended!

I believe the protocol is the same but there have been some major changes to the DBschema version.
R5F27 DBSchemaVer 1160 (myth .20.2?)
R5.5 DBSchemaVer 1214 (myth .21.?)

I had a ubuntu .21 frontend connect to my KM .20.2 backend and it upgraded the DB for me and caused all sorts of problems.

http://mysettopbox.tv/phpBB2/viewtopic.php?t=18480&postdays=0&postorder=asc&start=8

Grant,
Not sure if this helps but when I upgraded to R5.5 I had to upgrade my sons MythTV Player due to the protocol change.

His mythtvplayer version 0.4.2 lists this in the changelog.

I can't recall what R5f27 was but I had to make the mythtv player change because it didn't know the new protocol.

hth.

That's encouraging.

AFAICT from the changelog, R5.5 and R5F27 are both 0.20.1.
That's the most recent version listed in the changelog file
prior to R5.5.

However, my R5F27 system says this in /etc/mythtv/version

I'm a bit lost as to how one determines what version of MythTv
is in a given version of KM.


Despite what's in the changelog file, I think my R5F27 backend
is 0.20.2. So, I'm hoping that a MiniMyth frontend running
0.20.2 will work (or at least won't cause permanent damage).

I've never had any luck with auto-upgrading, so whenever I get
around to it, I'll probably just do a clean install of R6 and
manually transfer some of the database tables.

_________________
Grant

Yes for MythTV Player it allows you to specify the range of acceptable protocols, so all one has to do was increase this to I think 41 or 42 to get it to work with R5.5. Playing and deleting recordings works fine for me here, so it seems like the protocol is fairly backwards-compatible.

The only thing that doesn't seem to work anymore is LiveTV but I'm not sure if that's because of the protocol or if it's because my tuner number changed from 1 (under R5F27) to 65 (R5.5) and now it can't find it. Anyhow LiveTV is flaky on Player as it is.

The question then is does a real (full) frontend use the protocol or a direct DB connect, and from what goofee said it sounds like the latter...

R5F27 is 0.20.2 AFAIR ( at the time I used 0.20.2 generic myth as an MBE with R5F27 front ends)

R5.5 is 0.21-fixes

I agree with paulsid with mythtv player. I run the latest R5.1pre10 and had to edit the config file to up the protocol version. But mythtv player simply uses the protocol and not the schema so that is ok.

I now have R5.5 running on the front ends and MBE. I have a slave BE running generic (and more recent) 0.21 out of atrpms with no issue.

I'm told that in general releases at the same version should be protocol compatible so if minimyth is available as 0.21-fixes then you should be ok.

Just remember to back-up your database just in case!!!

C

Sorry. My bad.
I miss read your first post as you were hoping to connect a minimyth .20.2 frontend with a .21 backend. That I wouldn't recommend.
I have 2 different changesets of the same release .21 runing without issue. I agree that running different changesets _shouldn't_ matter as long as they are the same release.
Sorry.

That tells me that my 5.5 BE is using 40. You can also do:



Yes. It is possible to compile MythTV to ignore the protocol differences, but you risk breaking things.


Not all. If you stick to major releases (0.19, 0.20, 0.21), you have no problems

That MythTV Wiki page now lists some release versions in the table. Doesn't help much if you want to match it to KnoppMyth versions, though.

...
Try http://www.knoppmythwiki.org/index.php? ... h_Releases

_________________
| Nigel Pearson, nigel.pearson.au@gmail.com
| "Things you own end up owning you" - Tyler, Fight Club