[mythtv-users] 2Backends

[Stephen Worthington]

On Thu, 8 Dec 2016 20:38:16 +0800, you wrote:

>
>> On 8 Dec. 2016, at 8:00 pm, mythtv-users-request at mythtv.org wrote:
>> 
>>>> 
>>>> On 6 Dec. 2016, at 10:43 am, mythtv-users-request at mythtv.org wrote:
>>>> 
>>>>> What is the underlying reason you want to run 0.27 version ? Maybe you can
>>>>> solve the issue and use 0.28 and one backend.
>>>> 
>>>> I want to make sure 0.28 works fine before swapping, which it does not do!
>>>> 
>>>> First I?m not silly or naive - I?ve been using and configuring and building from src since 0.18
>>>> 
>>>> Time to spelunk the src, 
>>>> 
>>>> (1) my 0.28 frontend keeps displaying, then removing, then displaying again the ?Cant connect to master backend message?. At all times a mysql -h bla -umythtv -pbla mythconverg from anywhere in the network works. Shutdown of the 0.27 machine has no effect.
>>>> 
>>>> (2) Play a video fails (there is no antenna on the 0.28 machine so live TV and recording are not tested yet).
>>>> The Video page does show the videos by name, no pictures though, but play on a remote machine says
>>>> Failed to access remote file myth://Videos@bla/whateverName.mpg
>>>> 
>>>> jam at poohcorner:~$ ls -l /store
>>>> total 24
>>>> drwx------ 2 root root 16384 Dec  5 11:12 lost+found
>>>> drwxrwxrwx 2 root root  4096 Dec  7 11:28 Movies
>>>> drwxrwxrwx 8 root root  4096 Dec  5 15:59 OwnCloud
>>>> jam at poohcorner:~$ ls -l /store/Movies
>>>> total 88802296
>>>> -rw-r--r-- 1 jam jam 2276717036 Dec  5 14:46 7DMAdmirer12.mpg
>>>> -rw-r--r-- 1 jam jam 1924607700 Dec  5 14:49 7DMAlwaysOnMyMind6.mpg
>>>> etc
>>>> 
>>>> The 0.28-backend machine *does* play videos on it?s frontend, though wierd in the extreme is to watch a recording with the ?Can?t connect to Master Backend? overlaid. After a few seconds it fades, then is redisplayed.
>>>> 
>>>> Short of trying other hardware I cannot think of a thing to do. I have tried several installs of mythbuntu-16.04.1 this one with no fiddling except to set a root mysql password, set the mythtv password to something sane, and allow 192.168.5.% access.
>>>> 
>>>> (lest this provokes a storm: my machine has no internet access to it, my wife will not hack my network, and wireless access has a reasonable PSA password, what on earth is the point of bizare passwords?)
>>>> 
>>>> If anybody has ideas or suggestions, that would be most helpful.
>>> 
>>> This is critique not criticsm, but does serve as a Beware regarding mythbuntu. I shall revert to the harder but more certain ways
>>> I installed afreash on a new machine (actually an older amd64)
>>> 
>>> jam at 6pines:~$ mythtv-setup
>>> mysql: [Warning] Using a password on the command line interface can be insecure.
>>> ERROR 130 (HY000) at line 1: Incorrect file format 'settings'
>>> status: Name "com.ubuntu.Upstart" does not exist
>>> libGL error: No matching fbConfigs or visuals found
>>> libGL error: failed to load driver: swrast
>>> Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.
>>> Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.
>>> 
>>> Back to square 1.
>>> James
>> 
>> I do have to wonder how you managed that, as I have never had anything
>> like that from a Mythbuntu 16.04 or 16.04.1 clean install.  Are you
>> getting that immediately after the install completes, or after you
>> have been adjusting things?
>
>Stephen with mythbuntu 14.04 I have had good experience over the years.
>I installed 16.04.1 on 4 machines. I fiddled the first install, but the rest were clean.
>The first 3 did *not* work the last did. Using hindsight I went back and made machine 1 work.
>
>Machine 1: 2012 mac mini - i5 core duo, 4G RAM, 500G disk
>Machine 2: amd64 4G/500G dual core (old so I forget detail)
>Machine 3: nuc i5 4G/128G (duo)
>Machine 4: nuc i3 4G/256G (duo)
>
>To get machine1 to run I enable mythbackend.service with systemctl
>I removed the .config/autostart/setup.desktop link
>
>All somewhat daunting to the neophite, doubly daunting to see ‘Can’t connect to master backend’ overlaid over the movie you’re watching!!
>
>My last hurdle (wireshark tomorrow) on 0.27 I play a video over uPnP on my samsung tv. On 0.28 the same video has the samsung complaining ‘unsupported file format’. It must be a naming thing.
>
>I’d like to believe I was being harsh, but the issues I’ve had have been pretty harsh.
>I assume that the hardware has an effect on the install (actually I’m certaiin it does)

You did read my earlier reply about needing to modify the systemd
settings for mythbackend when you are using external access (eg
network tuners or external frontends)?  That is the usual cause for
your problems, and is easy to fix from the instructions posted
recently on this list.  If you stop and restart mythbackend on a
systemd system like 16.04, and it works properly when restarted, then
it is most likely that systemd is starting it too early for its
requisite hardware and drivers to be accessible (network and tuners).
Mythbackend is not sophisticated about handling that situation in the
way MySql is - if the tuners or network are not accessible when it
starts up, it never goes back and checks later to see if they are now
available and instead starts in a mode where it does not use them.  So
only the localhost interface gets used, and any tuners that did not
work when first tested are marked as bad and it ignores them after
that.

The fix that I worked out has been included in Jim Abernathy's PDF
file on how to install 16.04.1 available from his blog, which is
easier to find than searching this list:

http://mythtvinstall.blogspot.com

Unfortunately the Mythbuntu distribution is now unsupported software,
and its team has been at rock bottom levels even before that, so the
16.04 release did not have sufficient testing and hence had this
problem with the systemd settings.  It does not affect a fairly large
proportion of Mythbuntu users who only have simple combined
frontend/backend setups.

Most distros now seem to be using systemd, so you would likely run
into exactly the same problem with recent versions of them also, as
the MythTV developers do not provide the setup to make various distros
work - that has to be done by whoever packages MythTV for the distro.
And systemd does not make it easy to provide a generic config for it
that will make mythbackend work for everyone.  It needs to be
customised a little for your particular setup.  That also applied
somewhat with upstart in Ubuntu 14.04 - mythbackend could get started
in 14.04 before the external network interface was up, but due to the
way upstart worked, mythbackend was started much later in the startup
procedure, making it much less likely.  I did have that problem in
14.04 and needed to modify its control file too.  And having SSD boot
drives aggravates the problem - they allow much more parallelism in
the startup procedure, which systemd takes advantage of in a way
upstart did not, and lots of software gets started much earlier that
it used to.