Freeradius and check connection to DB

[vanish]

Hello, we have: 
 - test-machine with Ubuntu 14.04 and Freeradius-server v2.1.12
 - Informix Database Server v 10.00
 - freeradius connected to DB through iODBC driver
 
When restarted Informix on server, freeradius still holds the
connections (old connections) to database. 

And for all access-request packets in debug mode i see:

 Error: sql_create_socket: SQLAllocStmt failed:  [Informix][Informix
ODBC Driver]Connection not open.
 Error: [main_sql] Couldn't update SQL accounting ALIVE record -
[Informix][Informix ODBC Driver]Connection not open.
 
Freeradius has functional for restart his connections when database
restarted?
How i can catch this problems? Only in debug log?