Crash / exit of master when proxying

[Phil Mayers]

All,

FYI our testing server running "master" died today when the upstream UK 
eduroam servers became briefly unavailable.

Unfortunately I'd mistakenly disabled generation of core dumps when 
porting the config to the new 3.0 structure, so all I've got is the 
logs. It seems to have become confused

Proxy: Marking home server 194.83.56.249 port 1812 as zombie (it looks 
like it is dead).
Proxy: Marking home server 194.83.56.249 port 1812 as dead.
Proxy: (47522) Received response to status check 47522 (1 in current 
sequence)
Proxy: (47521) Failed to insert entry into proxy list.
Proxy: (47521) Failed to insert retransmission into the proxy list.
Proxy: No outstanding request was found for reply from host 
194.83.56.249 port 1812 - ID 83
Error: Request 47521 has been waiting in the processing queue for 10 
seconds.  Check that all databases are running properly!
Proxy: (47531) Received response to status check 47531 (2 in current 
sequence)
Proxy: Marking home server 194.82.174.185 port 1812 as zombie (it looks 
like it is dead).
Error: No response to status check 47533 for home server 194.82.174.185 
port 1812
Proxy: (47542) Received response to status check 47542 (3 in current 
sequence)
Proxy: (47542) Marking home server 194.83.56.249 port 1812 alive
Proxy: Marking home server 194.83.56.249 port 1812 as zombie (it looks 
like it is dead).
Proxy: Marking home server 194.83.56.249 port 1812 as dead.
Proxy: (47544) Received response to status check 47544 (1 in current 
sequence)
Proxy: No outstanding request was found for reply from host 
194.83.56.249 port 1812 - ID 197
Proxy: Marking home server 194.82.174.185 port 1812 as dead.
Proxy: (47545) Received response to status check 47545 (1 in current 
sequence)
Error: Request 47543 has been waiting in the processing queue for 14 
seconds.  Check that all databases are running properly!

...and then it stops. It had been up for a few days at this point. 
Config is normal UDP proxying.

I've enabled core dumps and will try to reproduce it.