[mythtv-users] MythSocket errors, backend unresponsive

[R. G. Newbury]

On 08/06/2010 11:09 AM, Bob Cottingham wrote:
> On Thu, Aug 5, 2010 at 6:57 PM, Khanh Tran<khanh at khanh.net>  wrote:
>> somewhere around r25084 (I'm running from -fixes branch), I started seeing
>> the following errors in my master backend:
>>
>> 2010-08-05 19:33:37.397 MainServer, Warning: Unknown socket closing
>> MythSocket(0xffffffffa9634c38)
>> 2010-08-05 19:33:37.401 MythSocket(ffffffffa9634c38:-1): writeStringList:
>> Error, socket went unconnected.
>>                          We wrote 0 of 10 bytes with 1 errors
>>
>> The backend process doesn't segfault, but nothing can connect or use it
>> either.  Sometimes, I get the following errors in the frontend logs:
>>
>> 2010-08-05 19:00:46.554 MythSocket(ffffffffb3a6bd10:35): readStringList:
>> Error, timed out after 30000 ms.
>> 2010-08-05 19:00:46.554 Connection to backend server lost
>> 2010-08-05 19:00:46.554 MythContext: Connecting to backend server:
>> 192.168.1.3:6543 (try 1 of 1)
>> 2010-08-05 19:00:53.554 MythSocket(ffffffffa4b00c98:35): readStringList:
>> Error, timed out after 7000 ms.
>> 2010-08-05 19:00:53.554 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.
>> 2010-08-05 19:00:53.554 Reconnection to backend server failed
>>
>> Anyone else experiencing this?  Have a workaround or fix?
>
> Are you running a slave backend?  I've been having issues like this
> since .22-fixes whenever I run my slave backend.  Without the slave
> backend my master is very stable.  I've seen several people mention
> issues like this, but never a solution.  I have ticket #7608 open for
> my issue, but haven't had a single comment.

Every time I have had the 'Protocol version check failure' error, it has 
been because myth cannot communicate properly with mysql. My latest 
instance was from copying over a settings table from my desktop, onto my 
laptop instead of just copying it for review. So the hostname data was 
entirely borked and myth would not talk to mysql since the mythtv user 
was now on the wrong domain and myth was trying to talk to the mysql 
server on the desktop machine.

Use mythtv-setup -> general to ensure that the box is talking to the 
correct place, then take a look at the mysql settings table, and in 
particular look out for duplicate instances of a 'value' field and that 
the hostname field is correct. You should also check any mysql.txt or 
config.xml files for the correct address.. and finally, check that mysql 
'likes' you, by using the user at domain authentication for the mysql 
console or check the /var/lib/mysql/mysql/user table entries for 
host,user and password fields. phpMyAdmin is great for this if you are 
not comfortable using the mysql console and SQL commands.

              R. Geoffrey Newbury