Need help on one issue.

We recently configured stunnel on our servers for securely establishing DB connections[certs exchanged on stunnel client and server]. 

Stunnel installed on client machine.

Stunnel installed on server machine. Configurations are completed and publishing working for sometime like 1 hr.

After that the stunnel on the destination server did not respond and we noticed "SSL socket error: Connection timed out (110)". We made updates to the stunnel.conf with below entries but they are not updating.