[mythtv-users] MySQL related BE deadlocks - collective wisdom needed

[Brian J. Murrell]

On 11-07-25 04:59 AM, David Edwards wrote:
> 

At this exact moment, my backend is not responding to any frontends and
is reporting in it's logs:

2011-07-28 19:01:15.472 MythSocket(a035b18:11): readStringList: Error,
timed out after 7000 ms.
2011-07-28 19:01:15.473 Protocol version check failure.
			The response to MYTH_PROTO_VERSION was empty.
			This happens when the backend is too busy to respond,
			or has deadlocked in due to bugs or hardware failure.

> I do not know the MythTV code at all, but that does look like it is waiting
> for (or actually reading) data from the DB. Have you looked at what queries
> are running when Myth hangs? Try connecting to the database using the mysql
> command line tool and running "show full processlist;" to see what it is up
> to.

It doesn't mean much to me, but here's mine:

+-----+--------+-----------+-------------+---------+-------+-------+-----------------------+
| Id  | User   | Host      | db          | Command | Time  | State |
Info                  |
+-----+--------+-----------+-------------+---------+-------+-------+-----------------------+
| 138 | mythtv | localhost | mythconverg | Sleep   |  2410 |       |
NULL                  |
| 519 | mythtv | localhost | mythconverg | Sleep   | 12320 |       |
NULL                  |
| 520 | mythtv | localhost | mythconverg | Sleep   | 12312 |       |
NULL                  |
| 608 | mythtv | localhost | mythconverg | Sleep   |     2 |       |
NULL                  |
| 609 | mythtv | localhost | mythconverg | Sleep   |    12 |       |
NULL                  |
| 610 | mythtv | localhost | mythconverg | Sleep   |     2 |       |
NULL                  |
| 612 | mythtv | localhost | mythconverg | Sleep   |  1711 |       |
NULL                  |
| 615 | mythtv | localhost | mythconverg | Sleep   |   170 |       |
NULL                  |
| 617 | root   | localhost | NULL        | Query   |     0 | NULL  |
SHOW FULL PROCESSLIST |
+-----+--------+-----------+-------------+---------+-------+-------+-----------------------+
9 rows in set (0.00 sec)

Anything useful there?

I'm just about to install the latest fixes with Michael's small
"MYSQL_OPT_RECONNECT=1" patch posted in another message.

b.

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