[mythtv-users] mythv 0.25 issues
Michael T. Dean
mtdean at thirdcontact.com
Sun Apr 8 22:28:52 UTC 2012
On 04/08/2012 05:27 PM, Scott & Nicole Harris wrote:
>>>>>> So it is very strange that mythtv-setup does not create proper
>>>>>> schema ?
>>>>>> On new setup I had start mythbackend in order to get proper
>>>>>> database config and then run mythtv-setup.
>>>>>> Another issue is that I can't get lineup from schedule direct at
>>>>>> all works fine with 0.24 fixes.
>>>>>> I have pfsense running with antivirus and squid. I wonder if
>>>>>> anyone has any idea on how I can fix that issue.
>>>>>> Upgrading from 0.24 fixes to 0.25 creates database error issue.
>>>>>
>>>>> I had the db error issues as well. I had to start mythbackend
>>>>> from the command line to see what was going on then manually drop
>>>>> tables / columns one at a time as it complained about it and
>>>>> failed until it stopped complaining. The problem is, if it fails
>>>>> part way through, but say has already added a new table or a new
>>>>> column to an existing table, then next time through, it isn't
>>>>> happy because things it's trying to do (again) have already been
>>>>> done.
>>>
>>>> Exactly, which is why, if you have a failed DB update, you need to
>>>> restore the pre-upgrade backup and then try a new upgrade. We
>>>> don't support upgrading partially upgraded databases--because we
>>>> have absolutely no checking for what failed and what succeeded and
>>>> we don't have transaction support, so the schema is always in an
>>>> unknown condition when a DB upgrade fails.
>>>
>>> When I upgraded my production setups to 0.25, I spent 2+ hours that
>>> morning on a fresh installation of Mythbuntu trying to get the
>>> upgrade to go through, having it fail, restoring my original 0.24
>>> db...rinse, wash, repeat before I threw in the towel and manually
>>> addressed each issue it complained about. "Can't do x because y
>>> already exists" -> drop y, try again -> "can't do a because b.c
>>> already exists" -> remove column b.c, try again, etc). After about 5
>>> iterations of addressing complaints, it finally succeeded.
>
>> Note that you should never--with a proper database schema--get such a
>> message (proper schema means, also, no failed DB upgrades with that
>> schema). However, it's quite easy to get them when you restore a DB
>> backup of a 0.24-fixes system, for example, on top of a "pre-created
>> by the distro/package-manager" 0.25 schema (as you might get on a
>> "new install"--versus just upgrading MythTV on an existing system).
>> What you should do when restoring a database backup on top of an
>> existing schema is the "replace" option:
>
>> http://www.mythtv.org/wiki/Database_Backup_and_Restore#Replacing_an_existing_database
>>
>
>> And, as far as 0.25 goes, nothing in the 0.25 upgrades should cause
>> any issues with any 0.24 database. So, could it have just been
>> something like the above?
>
> I don't use the backup / restore scripts when doing my upgrades.
You mean the scripts that check the database/schema to make sure you
don't miss steps like dropping the database and that do a ton of other
checks for things that users tend to forget that we've determined over
the years cause problems after the restore "succeeds"? ;)
> I just use the MySQL Workbench and do a backup to a "safe" location
> (i.e. somewhere Myth won't ever touch during any procedures I am about
> to embark on) immediately before I begin the fun. When restoring I
> also use the MySQL Workbench, but having been stung way back in the
> ~.20 -> 0.21 era, I am careful to "DROP IF EXISTS mythconverg" and
> usually manually drop the mythconverg schema myself with the Workbench
> before importing, which I would assume (knowing full well what assume
> makes of you and me ;)) amounts to the same as the "replace" option of
> the restore script.
>
> Having said that, did I do it this time? I think so, but it was a
> Saturday morning too :).
>
>> If there are problems, though, I can't fix them unless someone
>> reports them.
>
> Fair enough, I probably should have posted logs. Sometimes when I 've
> been frustrated by something, I'm just happy to have gotten it
> resolved on my own and move on.
Well, if others have problems, please get me logs. I keep hearing about
issues, but haven't seen any usable bug reports or logs (and my
upgrades--from 0.21 schema, until that was no longer supported for
master and now from 0.22 schema--work perfectly with full plugin schemas
and everything, and I do them about once a week to try to make sure
there are no problems). And my Magic 8 Ball hasn't been too helpful at
finding issues, so I really need those logs. :)
Mike
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