[mythtv-users] Re: Myth having problems communicating across master/slave backends

Tue Aug 23 17:03:24 UTC 2005

On 8/18/05, Chad <masterclc at gmail.com> wrote:
> Hello!
> 
> I have been struggling trying to work out a bug that is keeping the
> man down for quite a while.  I've searched the archives, and tried a
> few different ideas (like reinstalling everything from X.org to nvidia
> drivers, to myth) but nothing changes my problem(s) (the (s) is
> because I believe they are all related...)
> 
> Ok, to summarize:
> 
> When I connect to mythweb, I do so by going to the Master BE's URL:
> http://mbe/mythweb
> 
> This works out, I get the program listings just fine.  I can hop
> around to a few of the tabs, but when I click on backend status, it
> dies and gives me the following error:
> ------------------------
> User Notice at /var/www/localhost/htdocs/mythweb/includes/mythbackend.php,
> line 159:
> Unexpected response to MYTH_PROTO_VERSION 'MYTH_PROTO_VERSION 15':
> Fatal Error at /var/www/localhost/htdocs/mythweb/includes/mythbackend.php,
> line 32:
> Unable to connect to mythbackend, is it running?
> 
> The system administrator has been notified and the problem will be
> remedied shortly.
> ------------------------------
> 
> In the browser window.
> 
> Related summary of another error:
> When I fire up mythfrontend (on a remote frontend/slave backend
> system) I will sometimes get an error in the startup dialogue that
> coincides with the above error about MYTH_PROTO_VERSION.  However, in
> mythcontext.h (which on my system is
> /usr/include/mythtv/mythcontext.h) the version is indeed 15, which
> matches with mythweb's version in /mythweb/includes/mythbackend.php
> 
> So, let me explain my setup, and tell you what I've tried and what
> progress I have made, and where.
> 
> I have 2 backends.  They are both also frontends, and are both running
> Gentoo.  The master is an AMD64, has 2 bt8x capture cards, and works
> fine by itself.  The slave is an AMD 2200+ has 1 saa7134 and 1
> pchdtv3000 (using DVB) card.  It also works fine by itself (as a
> slave, never tried switching which is master and which is slave).
> However, the problems begin to arise if I choose a recording that was
> captured on the remote box (whether it be the slave has the file, or
> the master).
> 
> Recently, I tried to make progress by troubleshooting this with
> mythweb, and it seems I may have gotten somewhere.
> 
> I generally access mythweb on the master backend.  As noted above,
> this works until I click something that must access the slave backend
> data, and then dies with the above info.
> So I decided to setup and access mythweb on the slave using the
> slave's implementation (meaning I used the slave's hostname in the
> url).  It errored out immediately.  I thought that was odd since I can
> usually get the first screen at least.  So I edited MYTH_PROTO_VERSION
> in mythweb/includes/mythbackend.php to 14 (it's set at 15 just as
> every other one on the system is) saved, and went the URL again.  This
> time I got the error telling me mythweb=14 mythtv=15 version mismatch.
>  Woohoo!  So I edited it back to 15, and SUCCESS!!!...  For a minute.
> As soon as I clicked on backend info, it returned with the error noted
> earlier:
> -------------------
> User Notice at /var/www/localhost/htdocs/mythweb/includes/mythbackend.php,
> line 159:
> Unexpected response to MYTH_PROTO_VERSION 'MYTH_PROTO_VERSION 15':
> Fatal Error at /var/www/localhost/htdocs/mythweb/includes/mythbackend.php,
> line 32:
> Unable to connect to mythbackend, is it running?
> 
> The system administrator has been notified and the problem will be
> remedied shortly.
> -------------------------
> 
> And now I can't do anything to make it work.
> 
> BUT it seems that I may have tracked down the culprit, or at least
> narrowed my search to the slave backend.
> 
> Something I've noticed since that may give a clue to what's going on:
> 
> I have to spawn myth by calling it directly (as root) with:
> # /usr/bin/mythbackend -d -l /var/log/mythtv/mythbackend
> 
> I do this on both machines because the init script doesn't work out
> the box, and... (it's another story)...
> On the machine that works fine, the master backend, I get 1 instance
> of mythbackend:
> -----------------
> ps aux | grep myth
> root     13119  0.0  7.5 249988 76932 pts/3    Sl+  Aug17   0:36 mythfrontend
> root     14775  3.2  1.7 183440 17880 ?        Ssl  03:38   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> masterc  14788  0.0  0.0   2700   520 pts/0    R+   03:38   0:00 grep myth
> ---------------------
> But on the slave I get quite a bit of multiples:
> ---------------------
> root      1906  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1908  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1910  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1911  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1912  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1913  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1914  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1915  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1916  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1917  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> root      1918  0.0  3.6  63716 18832 ?        S    03:39   0:00
> mythbackend -d -l /var/log/mythtv/mythbackend
> masterc   1921  0.0  0.0   1500   508 pts/2    S+   03:39   0:00 grep myth
> ------------------------------
> 
> During both of these queries, nothing is happening (nothing is being
> recording, nothing is being flagged or transcoded by mythbackend on
> either machine).
> 
> So for now, I'm blaming the multiple instances.  But...  I don't know
> how to get rid of them (I do know how I can kill -9 their PID) on a
> longterm basis, or why they are even spawning.
> 
> Any ideas are very welcome.  As noted above, I have tried uninstall
> everything completely and reinstalling everything completely that is
> remotely related to myth, but the result doesn't change.
> 
> Thanks for any ideas, and I am very open to obvious pointers!  :)
> 
> Thanks!

Does anybody have any ideas?  I know it's a long post, but I didn't
want to leave out any pertinent info.