[mythtv-users] mythbackend not responding on port 6543

[Stephen Worthington]

On Wed, 16 Nov 2016 20:55:35 -0800, you wrote:

>On Wed, Nov 16, 2016 at 6:59 PM, Stephen Worthington <
>stephen_agent at jsw.gen.nz> wrote:
>
>> On Tue, 15 Nov 2016 07:04:34 -0800, you wrote:
>>
>> >On Tue, Nov 15, 2016 at 5:41 AM, Stephen Worthington <
>> >stephen_agent at jsw.gen.nz> wrote:
>> >
>> >> On Tue, 15 Nov 2016 01:33:53 +1300, you wrote:
>> >>
>> >> The conclusion I reached from this is that the problem is related to
>> >> my database somehow, rather than the versions of any software I am
>> >> running.  Something about my current database triggers the problem.
>> >>
>> >>
>> >It might be enlightening to do a dump and diff of the settings table from
>> >your working vs. non-working backups.
>> >
>> >Karl
>>
>> Thanks for the idea.  Doing it with database tables is a just a *bit*
>> more difficult than using the diff command, but I worked it out.  So
>> can anyone see any problems in the diff?  I can not.
>>
>> If you can not read it properly in your email program, I have also put
>> it in a file on my web server:
>>
>>   http://www.jsw.gen.nz/mythtv/6543/settings_diff.txt
>>
>> MariaDB [mythconverg]> select hostname,value,data from (select
>> s.hostname,s.value,s.data from settings s union all select
>> o.hostname,o.value,o.data from settings_old o) t where hostname is
>> null or hostname='mypvr' group by hostname,value having count(*)=1
>> order by hostname,value;
[snip]
>I was thinking of something conceptually simpler, like doing a select on
>each settings table, dumping the results to a text file and then diff'ing
>the two files (an ORDER BY clause could help there). Since your statement
>is doing a union, it doesn't show the differences (if any).
>
>Karl

Yes, it does show the differences.  It is using a sneaky sql trick
from this page:


http://www.mysqltutorial.org/compare-two-tables-to-find-unmatched-records-mysql.aspx

Trying to do a text diff of tables is quite difficult, due to the
variable length of fields and the way the output table is formatted to
accommodate only the longest actual length of a field.  You have to do
fixed length formatting on all fields to have a chance for a text diff
to work.