[mythtv-users] Running mythfrontend with mysql 5.5 client against mybackend using 5.7

[Jean-Yves Avenard]

After reinstalling the mysql backup and following the procedure on how
to upgrade mysql database from 5.5 to 5.7; I then restored the
mythconverg backup made with mythconverg_backup script, using
mythconverg_restore.

I can now at least run one frontend against the backend. playback
starts. that's progress.

However, in the backend logs, I see heaps of entries like:

2016-12-02 17:00:04.905163 E  Error preparing query: SELECT recgroup
FROM recorded WHERE chanid    = :CHANID AND       starttime = :START
2016-12-02 17:00:04.905169 E  Driver error was [2/2013]:
QMYSQL3: Unable to prepare statement
Database error was:
Lost connection to MySQL server during query

2016-12-02 17:00:04.905522 I  MySQL reconnected successfully
2016-12-02 17:00:04.918187 E  Error preparing query: SELECT chanid
FROM channel, capturecard WHERE capturecard.sourceid =
channel.sourceid AND       channel.channum = :CHANNUM AND
capturecard.cardid = :INPUTID
2016-12-02 17:00:04.918195 E  Driver error was [2/2013]:
QMYSQL3: Unable to prepare statement
Database error was:
Lost connection to MySQL server during query

2016-12-02 17:00:04.918636 I  MySQL reconnected successfully
2016-12-02 17:00:04.919070 N  AutoExpire: CalcParams(): Max required
Free Space: 42.0 GB w/freq: 14 min
2016-12-02 17:00:04.922478 E  Error preparing query: SELECT name FROM
playgroup WHERE name = :TITLE1 OR       name = :CATEGORY OR
(titlematch <> '' AND        :TITLE2 REGEXP titlematch)
2016-12-02 17:00:04.922486 E  Driver error was [2/2013]:
QMYSQL3: Unable to prepare statement
Database error was:
Lost connection to MySQL server during query

2016-12-02 17:00:04.922801 I  MySQL reconnected successfully
2016-12-02 17:00:04.926921 N  ApplyRecordRecGroupChange: LiveTV to LiveTV (2)
2016-12-02 17:00:04.927288 I  TVRec[1]: TuningNewRecorder - CreateRecorder()
2016-12-02 17:00:04.994886 E  Error preparing query: SELECT data FROM
settings WHERE value = :KEY AND hostname = :HOSTNAME
2016-12-02 17:00:04.994893 E  Driver error was [2/2013]:
QMYSQL3: Unable to prepare statement
Database error was:
Lost connection to MySQL server during query

2016-12-02 17:00:04.995480 I  MySQL reconnected successfully
2016-12-02 17:00:05.178452 E  Error preparing query: SELECT chanid,
starttime FROM recorded WHERE recordedid = :RECORDEDID
2016-12-02 17:00:05.178458 E  Driver error was [2/2013]:
QMYSQL3: Unable to prepare statement
Database error was:
Lost connection to MySQL server during query

2016-12-02 17:00:05.179128 I  MySQL reconnected successfully
2016-12-02 17:00:05.223050 E  Error preparing query: SELECT data FROM
settings WHERE value = :KEY AND hostname = :HOSTNAME
2016-12-02 17:00:05.223056 E  Driver error was [2/2013]:
QMYSQL3: Unable to prepare statement
Database error was:
Lost connection to MySQL server during query

2016-12-02 17:00:05.223496 I  MySQL reconnected successfully
2016-12-02 17:00:17.505035 E  Error preparing query: SELECT recgroup
FROM recorded WHERE chanid    = :CHANID AND       starttime = :START
2016-12-02 17:00:17.505041 E  Driver error was [2/2013]:
QMYSQL3: Unable to prepare statement
Database error was:
Lost connection to MySQL server during query

2016-12-02 17:00:17.505460 I  MySQL reconnected successfully
2016-12-02 17:00:17.515907 I  TVRec[1]: Changing from WatchingLiveTV to None
2016-12-02 17:00:17.762916 N  Finished Recording: Container: MPEG2-TS
Video Codec: mpeg2video (720x576 A/R: 3 25fps) Audio Codec: mp2
2016-12-02 17:00:17.763475 I  TVRec[1]:
FinishedRecording(1007_2016-12-02T06:00:04Z) damaged
recq:<RecordingQuality overall_score="0"
key="1007_2016-12-02T06:00:04Z" countinuity_error_count="0"
packet_count="24062">
    <Gap start="2016-12-02T06:00:15Z" end="2016-12-02T07:00:00Z"
duration="3584" />
</RecordingQuality>

2016-12-02 17:00:17.764672 I  Playback sock(1c81780) 'mythmini' disconnected
2016-12-02 17:00:18.991831 I  Monitor sock(1c88670) 'mythmini' disconnected
2016-12-02 17:00:18.992254 I  Monitor sock(1c7ffe0) 'mythmini' disconnected


this is whenever a client watch live TV

ideas?
I can restore from a backup that is one day earlier and see if it's any better.