Create multithreaded script to reduce execution delay and to facilitate external requests

[g1patnaik]

Reduce execution delay

• Current script is set to sleep periodically to reduce continuous checks when not required. Because of the use of next_service_check, this periodic sleep is not required as the utility would do check only when this next_service_check is less than the current time. However adding sleep simply avoids contiously checking for this variable in loop (though it has a negligable impact I guess with smaller frequency checks like 60 sec)
• However this added sleep delays the execution time by atleast 30 seconds, than what is configured for each service.

Facilitate external requests or reloading configuration

• Implement a queue system with external messaging.

Idea: A queue executor thread, queue creator thread, internal/external messaging service, poller/push event mechanism