request for new parameter for disable promote (slave only mode)

Hi.

I want to build one master & multi slave environments to use physical replication.
Slave nodes have low hardware spec, so I changed max_connection server parameters, and try start slave node.
But I could not start slave nodes,
because CheckRequiredParameterValues function (in src/backend/access/transam/xlog.c) reject to set less values then master’s values.

It is maybe,
This concept is base on some slave node can be promte master.
In my enterprise environments, readonly slave nodes are not used as master.
For High availability of master node, I’m using non shared disk fail over (like using pacemaker),
Then my slave nodes are used for always readonly nodes.

I suggest that new server parameter is added, such like allow_promote = on|off.
If allow_promte set off then CheckRequiredParameterValues skip check slave node parameters.

If there is a better plan, it is welcome too.

Regards, ioseph.