Databases that reside on a private network behind a firewall may be difficult to access from a cloud platform on the Internet. Techniques disclosed herein allow an Internet system to communicate with multiple different databases behind multiple different firewalls, however. A client-side private computer system, from behind a firewall, transmits a series of database request status inquires to a server system (not behind the firewall). These status inquiries may be sent as HTTP long poll messages. When the server wishes to query a database on the private network, it responds to one of the database request status inquiries. Because the client-side computer initiated communication, the server response is allowed to pass through the firewall when it might otherwise be blocked. Employing such techniques in parallel allows a server to interact with multiple firewalled databases without the difficulties and inconvenience of attempting a VPN connection.