Opened 9 years ago

Closed 9 years ago

#8679 closed defect (invalid)

mythfrontend deletes settings when db connection is "weak"

Reported by: thomas@… Owned by:
Priority: minor Milestone: unknown
Component: MythTV - General Version: 0.22
Severity: medium Keywords:
Cc: Ticket locked: yes

Description

For the third time, mythfrontend deleted my settings when somehow the connection to the backend was unstable.

I don't know, why the connection was unstable, because my frontend boots via PXE from the backend. And restarting mythfrontend solved the connection problems. So, I guess it was no hardware problem.

I did some investigation and found out that mythfrontend deletes data from the tables settings, displayprofiles, displayprofilegroups and inuseprograms in such a case.

It's strange that mythfrontend thinks, that reading from the tables fails, but still it is able to delete data from the tables.

From mythfrontend.log:


2010-06-12 08:30:56.858 Using the OpenGL painter 2010-06-12 08:30:58.429 Loaded base theme from /usr/share/mythtv/themes/Terra/base.xml 2010-06-12 08:30:58.645 Loaded base theme from /usr/share/mythtv/themes/default-wide/base.xml 2010-06-12 08:30:58.705 Loaded base theme from /usr/share/mythtv/themes/default/base.xml 2010-06-12 08:30:58.747 Current MythTV Schema Version (DBSchemaVer): 1244 2010-06-12 08:30:58.836 Error preparing query: SELECT name FROM displayprofilegroups WHERE hostname = :HOST 2010-06-12 08:30:58.836 Driver error was [2/2006]: QMYSQL3: Unable to prepare statement Database error was: MySQL server has gone away

2010-06-12 08:30:58.837 DB Error (get_profiles): Query was: SELECT name FROM displayprofilegroups WHERE hostname = :HOST Bindings were: :HOST=frontend Driver error was [2/2006]: QMYSQL: Unable to execute query Database error was: MySQL server has gone away

2010-06-12 08:30:58.841 Error preparing query: DELETE FROM displayprofiles WHERE profilegroupid = :PROFID 2010-06-12 08:30:58.841 Driver error was [2/2006]: QMYSQL3: Unable to prepare statement Database error was: MySQL server has gone away

[...]

2010-06-12 08:30:59.070 DB Error (create_profile_group): Query was: INSERT INTO displayprofilegroups (name, hostname) VALUES (?,?) Bindings were: :HOST=frontend, :NAME=CPU-- Driver error was [2/1062]: QMYSQL3: Unable to execute statement Database error was: Duplicate entry 'CPU---frontend' for key 1

[...]

2010-06-12 08:31:11.451 MythContext: Connecting to backend server: localhost:6543 (try 1 of 1) 2010-06-12 08:31:11.468 Connection to master server timed out.

Either the server is down or the master server

settings

in mythtv-settings does not contain the proper

IP address


After this incident, I restored the affected tables from the last backup and everything was OK again.

I think mythfrontend should display a message ("There is a problem, what shall I do?") in such a case, instead of deleting data.

Attachments (1)

mythfrontend.log (1.7 KB) - added by thomas@… 9 years ago.

Download all attachments as: .zip

Change History (5)

comment:1 Changed 9 years ago by thomas@…

Attaching the log text, because it looks messed up in the comment above. BTW, the log applies to the table displayprofilegroups, but the other 3 tables were also cleared in a similar way.

Changed 9 years ago by thomas@…

Attachment: mythfrontend.log added

comment:2 Changed 9 years ago by Raymond Wagner

Resolution: invalid
Status: newclosed

In mythtv-setup, general section, where it tells you put supply an IP for the backend, you must give it an actual IP. 'localhost' will not work.

comment:3 Changed 9 years ago by thomas@…

Resolution: invalid
Status: closednew

Of course, I did. The frontend boots and connects OK in 99% of the cases. Just every now and then, this problem occurs. The "localhost" in the log is a result of the lost connection to the database.

comment:4 Changed 9 years ago by robertm

Resolution: invalid
Status: newclosed
Ticket locked: set

Actually, no, the localhost in your log is because you have a setting with "localhost" instead of an IP address, as wagnerrp indicates.

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