[mythtv-users] 0.21 and 0.22 servers on the same network?

[f-myth-users at media.mit.edu]

    > Date: Wed, 07 Apr 2010 19:23:25 -0400
    > From: "Michael T. Dean" <mtdean at thirdcontact.com>

    > Personally, I'd like to remove the ability for any MythTV application to 
    > upgrade the database and require a user to explicitly request an upgrade 
    > through mythtv-setup.

Yay!
			   
    > 			   Others, however, like the current approach.  It 
    > /is/ much better now, than it has ever been in the past.  We no longer 
    > allow a frontend to ever upgrade the database (without an explicit 
    > command-line argument forcing the upgrade), and the program upgrading 
    > the database will make a backup before doing the upgrade.  I'm trying to 
    > convince others to let me change mythbackend so /only/ the master 
    > backend is allowed to upgrade the database. ...

Also yay!

I remember complaining rather loudly about the incredible risks of
autoupdate back in the 0.18.1 days, and it was one of many reasons
why I was very reluctant to -ever- do an upgrade---because I wanted
to test things on a separate machine first, without the potential
for touching my production setup, but (back then) there was no way I
trusted to be "safe enough" short of airgapping the relevant machines.
(Not to mention the risks of someone -else- starting up a different
version of myth anywhere on my network and screwing me that way.)
Frankly, even with the improvements, I am still nervous about it;
I seem to be excellent at tripping over corner cases like that in
software people swore were bug-free... :)

The current scheme makes the risks smaller, but there are still plenty
of ways to get screwed (as you have enumerated).  I was very happy to
see that many of the suggestions I'd made at the time (various ways of
prompting; automatic backups; etc) made it into later versions.  (So
thank you.)  But every way that makes it -harder- for an update to
happen behind my back is a welcome one in my book, given that it's
a one-way trip unless you have time and good backups (and your
existing backend had better not be currently recording or soon
to be recording even if you -do- have both of these, unless you
like missing recordings).

    > ***And maybe mythjobqueue--though I'm not sure if mythjobqueue is 
    > allowed to upgrade the database, but it doesn't matter because I'm the 
    > only person who uses mythjobqueue.

-I- use mythjobqueue...  So that's two of us. :)