There is a technology of clustering. How to optimize it?

Question

tunneling

Situation:
The server has 1 white IP. Server 2 has a gray IP. Server 1 is a free hosting, that's why it is limited: in php many necessary functions are forbidden, in mysql you can have a maximum of two tables of 4 KB each. Server 2 is not restricted, but is located behind the ISP's NAT.
The solution is to use this technology:
1. The user sends a request to the hosting (server 1) and waits for a response.
2. Hosting (server 1) writes the user's request to the table and starts updating it constantly, waiting for a response from server 2.
3. Server 2 constantly updates the request table and when new requests appear, writes its response to this table (if there are no new requests, the server 2 gets a 304 Not Modified error).
4. Hosting (server 1) finds the answer in the table and sends the answer to the user.
Problem:
It would be better if the host (server 1) sends the request to server 2 directly, rather than writing it to a table for server 2 to read later. But how to organize this using free hosting - php, mysql and htaccess, if the server has 2 gray IP?
The technology is designed to store search engine indexing results on a server with a gray IP, and access it through the hosting hash, since the hosting has a high connection speed with the client, and you don’t want to buy a white ip for the server, since it is planned to move the server frequently and every time it will be inconvenient to buy, I also plan to have more than one server, but rather than messing around with ports, hang each server on its own port, it would be better to write a small tunnel in php. I don’t want to use programs for tunneling, since servers can be with different OSes and in general this is a fuss. And besides, I am writing a framework and its users will really like the new feature - this will be one of its chips (the framework should not require any extensions, programs, plugins, etc., except for the php handler and any http server - this is another of his chips and on top of it is a CMS for creating templates and connecting widgets and a control panel, thanks to which you should not worry about setting up, building, installing, debugging, etc. applications is the third feature).

All questions on the topic:
How to use PHP on a hosting with a "white" IP to make an http tunnel to connect to a server with a "gray" IP, which is behind NAT'om?
How to get http access to a server with a gray IP from the Internet by any means?
There is a technology of clustering. How to optimize it?
How to create a persistent tunneling connection using php?
Will NAS timeouts interfere with my tunneling?
Can php receive and immediately process part of a request without waiting for the request to finish receiving?
Can php send information in chunks?
Most recent discussion.

Answer 1

With a bunch of your restrictions - no way, teamviewer uses its own servers to switch machines behind NAT, nothing will work without an intermediate point with a white IP.

Answer 2

Very simple.
Put your server on the Internet, connect to it via VPN or SSH tunnel, forward the port.

Answer 3

White address in the internet - a service. Paid service. ANY solution proposed here implies that it will take at least a little, but to spend money. Doesn't it surprise you that you have to pay for home Internet?