[mythtv-commits] Ticket #12612: New installs die after a few days fixes/0.27 (v0.27 (v0.27.5-71-ga62fc0d)

[MythTV]

#12612: New installs die after a few days fixes/0.27 (v0.27 (v0.27.5-71-ga62fc0d)
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 Reporter:  singogli@…            |          Owner:
     Type:  Bug Report - General  |         Status:  infoneeded_new
 Priority:  minor                 |      Milestone:  unknown
Component:  MythTV - General      |        Version:  0.27.5
 Severity:  medium                |     Resolution:
 Keywords:                        |  Ticket locked:  0
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Comment (by singogli@…):

 Well I finally solved this and am posting the details. The actual problem
 was hidden null characters in the database. Specifically the name field in
 the channel table and the service_name field in the channelscan_channel
 table. The actual mysql commands needed were: UPDATE channel SET
 name=REPLACE(name,'\0'''); and UPDATE channelscan_channel SET
 service_name=REPLACE(service_name'\0','');
 What obscured the solution were two things. First, the database works
 properly for a while. Only when a particular channel is selected for
 recording does the frontend lose contact with the backend. In my case
 since updates were coming through on an almost daily basis for the first
 week after the original build I would check the system in the morning and
 find that the error had occurred overnight. This was coincidental with
 having scheduled a recording overnight of a program on the problem
 channel.

 Secondly, these null bytes do not appear in the table when examined with
 PHPMyAdmin. The only way to discover them I could find was to backup the
 entire database with mysqldump and then search the entire database with
 gedit for the offending \0 byte. Once the problem is identified this way
 than the mysql replace commands do the fixes.

 Unfortunately the suggestions on how to locate null bytes did not work for
 me, mysql always reported a problem with the search string example: SELECT
 * FROM channel WHERE callsign LIKE '%\0%';
 And the tools for fixing a corrupt database always indicated the database
 was O.K.
 All the null characters that appeared with PHPMyAdmin were in fact
 irrelevant so I kept looking for a problem elsewhere.
 Apparently there is no "sanity check" on this raw channel data import.
 Perhaps in a future update?
 The channel that caused this is an Albuquerque OTA channel 21.3.

 What allowed me to solve this was a closed thread: Recordings suddenly
 gone?

 http://ubuntuforums.org/showthread.p...rtedList+Empty

 Scroll down to # 13 from BookofJarom.

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Ticket URL: <https://code.mythtv.org/trac/ticket/12612#comment:10>
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