Re: max_connections and standby server

On 11 August 2015 at 06:42, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Tatsuo Ishii <ishii(at)postgresql(dot)org> writes:
> > I think this is because pg_control on the standby remembers that the
> > previous primary server's max_connections = 1100 even if the standby
> > server fails to start. Shouldn't we update pg_control file only when
> > standby succeeds to start?
>
> Somebody refresh my memory as to why we have this restriction (that is,
> slave's max_connections >= master's max_connections) in the first place?
> Seems like it should not be a necessary requirement, and working towards
> getting rid of it would be far better than any other answer.
>

That was the consensus on how to control things on the standby, as 9.0
closed.

Yes, there are various other ways of specifying those things and these days
they could be made to react more dynamically.

There are various major improvements to hot standby that could have
happened, but that time has been spent on the more useful logical
replication which is slowly making its way into core. More coming in 9.6.

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