[mythtv-users] Bug in Mythbackend

[Peter Diffey]

Hi,

I am pretty sure that there is a bug in mythbackend. It may already be 
known so I report it  here before filing a bug report.

[root at myth2 mythcontrol]# uname -a
Linux myth2 2.6.15-1.1831_FC4 #1 Tue Feb 7 13:37:42 EST 2006 i686 i686 
i386 GNU/Linux

[root at myth2 mythcontrol]# mythbackend --version
Library API version: 0.19.20060121-2

My backend runs on a separate box to the frontend.

If the frontend dies for any reason, the TCP sockets on mythbackend 
never time out, I am left with legacy sockets that will stay there as 
long as the mythbackend process continues to run. The consequence is 
that the currently watched program  ( at the time of the crash ) holds 
on to the channel card forever, and when a new frontend is started, the 
user cannot watch live TV as the channel card is in use.

[root at myth2 mythcontrol]# netstat | grep 6543
tcp        0      0 192.168.1.3:6543            
192.168.1.125:39247         ESTABLISHED
tcp        0      0 192.168.1.3:6543            
192.168.1.125:39246         ESTABLISHED
tcp        0      0 192.168.1.3:6543            
192.168.1.125:45842         ESTABLISHED
tcp        0      0 192.168.1.3:6543            
192.168.1.125:45841         ESTABLISHED

I have tried modifying my tcp keep alives, but it appears that 
mythbackend does not monitor the connection status.

To overcome this problem mythbackend should use tcp_keepalive to check 
the status of any clients, and close down the session if the frontend 
goes away.

Aln alternative approach may be to have mythbackend destroy any old 
associations with a frontend, if the same frontend makes a new session 
request.

Peter Diffey
St Albans, UK