[mythtv] Questions about which components are meant for FE and BE

[Bruce Markey]

Joe Votour wrote:
> I'm working with Axel Thimm to try to reorganize the packaging for the
> Fedora RPMs, and I have some questions.  I've looked in the Wiki, and gone
> through the archives, and it seems that I'm left with more questions than
> answers.
> 
> There are several packages that can be pulled in via ATrpms, but there is
> the concept of a "mythtv-backend" and a "mythtv-frontend", which are
> intended for use in setting up minimal machines.  What brings this issue
> up is that mythcommflag and mythtranscode are included only in the

"What brings this issue up" is that you've made an assumption
that 'sounds about right' without giving enough thought to
it's merit.

> frontend packages, but I've known commercial flagging to be run only on
> the backend.

Despite this observation and an earlier misguided reply, these
jobs can be run from a backend where the show was recorded
(which makes the most sense), a different backend, a frontend
only, a combined frontend and backend machine or a machine that
normally doesn't run either.

> Given the list of these programs, which are meant for the backend, and
> which are meant to be located on the frontend?
> mythcommflag
> mythtranscode
> mythtvosd
> mythlcdserver
> mythshutdown
> mythwelcome
> 
> Knowing that MythTV is a client-server architecture, some programs are
> capable of being run on both a frontend and a backend (or any other
> machine, for that matter).  That may very well be the case for the above
> programs, but still, I figure I'll ask.

And I figure I'll answer =).

Here are the sizes of these executable on my system:

: bjm at moktoo ; ls -l myth*
-rwxrwxr-x 1 bjm  staff  943128 2006-10-12 17:05 mythbackend*
-rwxrwxr-x 1 bjm  staff  620544 2006-10-12 17:05 mythcommflag*
-rwxrwxr-x 1 bjm  staff  347588 2006-10-12 17:05 mythfilldatabase*
-rwsr-xr-x 1 root staff 1334764 2006-10-12 17:05 mythfrontend*
-rwxrwxr-x 1 bjm  staff   23392 2006-10-12 17:05 mythjobqueue*
-rwxrwxr-x 1 bjm  staff  270212 2006-10-12 17:05 mythlcdserver*
-rwxrwxr-x 1 bjm  staff   77044 2006-10-12 17:05 mythreplex*
-rwxrwxr-x 1 bjm  staff   80384 2006-10-12 17:05 mythshutdown*
-rwxrwxr-x 1 bjm  staff  336096 2006-10-12 17:05 mythtranscode*
-rwxrwxr-x 1 bjm  staff   37376 2006-10-12 17:05 mythtv*
-rwxrwxr-x 1 bjm  staff   17316 2006-10-12 17:05 mythtvosd*
-rwxrwxr-x 1 bjm  staff  234576 2006-10-12 17:05 mythtv-setup*
-rwxrwxr-x 1 bjm  staff  180332 2006-10-12 17:05 mythwelcome*

And here is the program that generated this output:

: bjm at moktoo ; ls -l /bin/ls
-rwxr-xr-x 1 root root 77480 2006-08-31 04:57 /bin/ls*

The "ls" executable is more than twice the size of the "mythtv"
binary. The only program that (barely) exceeds one megabyte
is "mythfrontend". Here is a bar graph (not to scale) to illustrate
the relative disk usage

The size of my shortest recorded program
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

The total size of all myth executables
.

I would have included the size of the smallest disk I could
purchase at CompUSA but the message would have been rejected due
to the size.

So let's say that someone set up a frontend only system without
a backend and without disk space for local video files. However,
they did put in an old 4GB disk for OS only (this doesn't make
sense to me but I need to contrive an example =). The system files
take up 2.5GB leaving 1.5GB free. Adding "mythtranscode" would
increase disk usage to 2.5003GB leaving only 1.4997GB free.

You are not doing the users a favor by making them make this
uninformed choice. If even one person ever wanted to run a
transcode job and was frustrated, it would offset any (perceived)
benefit to thousands and thousands of users.

Include all the libraries, executable, theme files, docs, contrib
scripts, etc. when installing "mythtv". Whether or not to configure
a system to run a backend is another question but there is no
benefit to excluding any of the files. Mythplugins is another
story and there the user should pick and choose which to include
or exclude as these affect what items are included in the menus.

--  bjm