[mythtv] mythzmserver killed my computer

[Martin Ebourne]

Ok, a bit dramatic, but reasonably accurate.

I installed mythzmserver on the server machine (which hosts mythbackend
and ZoneMinder 1.22.3), set it up, then tried to enter the zoneminder
screen in mythfrontend from a separate machine.

The result was that mythzmserver and/or zoneminder massively overloaded
the machine to the point where it appeared frozen. It was actually still
running - I killed the frontend first and then on the server typed
'killall mythzmserver' and when that hadn't appeared after 15 minutes I
went to bed and left it. This morning I saw that the characters had been
entered, but it hadn't got as far as killing anything. I should guess
that either something's created daft numbers of threads, fork bombed, or
screwed up the interrupts to cause a result like that.

After a hard reboot all that appeared in the mythzmserver log file was:

  loading zm config from /etc/zm.conf
  Listening on port: 6548
  Failed to shmget for monitor: 4

The frontend log had a lot of these in the few minutes until I killed
it:

  2007-01-09 00:59:30.822 Connection to mythzmserver lost
  2007-01-09 00:59:30.822 Connecting to zm server: 192.168.65.2:6548 (try 1 of 10)
  2007-01-09 00:59:38.327 MythSocket(3ca62a0:37): readStringList: Error, timeout (quick).
  2007-01-09 00:59:38.327 Connection to mythzmserver lost
  2007-01-09 00:59:38.327 Connecting to zm server: 192.168.65.2:6548 (try 1 of 10)
  2007-01-09 00:59:45.831 MythSocket(a587d0:37): readStringList: Error, timeout (quick).
  2007-01-09 00:59:45.831 Connection to mythzmserver lost
  2007-01-09 00:59:45.831 Connecting to zm server: 192.168.65.2:6548 (try 1 of 10)
  2007-01-09 00:59:53.337 MythSocket(a0d190:37): readStringList: Error, timeout (quick).

Nothing apparently relevant in any of the zoneminder log files.

Any clues what might be up with this? Do I need to make any changes to
shared memory settings?

Unfortunately debugging this would not be easy because it kills the
machine, and even worse this machine is very inaccessible, so even
resetting it is something of a problem. Hence I'm not keen to keep
retrying it unless there's a clear lead.

Cheers,

Martin.