Asterisk service is hung until restart this service at AsteriskNOW box

Hi,
We are not able to execute/run asterisk commands on CLI prompt, until to restart the asterisk service.it would be big trouble at production environment, so we are thinking about to reslove this problem as multiple way. Could you please give us any points about this ?
Note: CPU and memory usage are normal and not able to see any unbehavior on that box

After upgrading to the latest sub-version of your choice of supported version, if the problem is still there, see https://wiki.asterisk.org/wiki/display/AST/Getting+a+Backtrace#GettingaBacktrace-GettingInformationForADeadlock