Close the communication with the application server. Closing communication will lower pressure on application server, but will require time to establish it again for next request. This may be a problem on the internet. Communication will be established much faster if you use an IP address instead of a hostname because there is no need for name resolution which is often a very long process.
On a LAN, there is no problem to close communication after each request, specially if you use an IP address and not a hostname.
Note: Using IP address in a program is not recommanded because IP addresses may change. You should use a hostname and resolve the hostname to an IP address at startup and then use the IP address for the program duration.