Re: pgbench: could not connect to server: Resource temporarily unavailable

On Tue, Aug 23, 2022 at 4:57 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> 0001 adds a para about how to raise the listen queue length.

+ service the requests, with those clients receiving unhelpful
+ connection failure errors such as <quote>Resource temporarily
+ unavailable</quote>.

LGTM but I guess I would add "... or Connection refused"?

> 0002 isn't quite related, but while writing 0001 I noticed a nearby
> use of /proc/sys/... which I thought should be converted to sysctl.
> IMO /proc/sys pretty much sucks, at least for documentation purposes,
> for multiple reasons:

+1

> 0003 removes PG_SOMAXCONN. While doing that I noticed that this
> computation hadn't been touched throughout all the various
> changes fooling with exactly what gets counted in MaxBackends.
> I think the most appropriate definition for the listen queue
> length is now MaxConnections * 2, not MaxBackends * 2, because
> the other processes counted in MaxBackends don't correspond to
> incoming connections.

+1

> I propose 0003 for HEAD only, but the docs changes could be
> back-patched.

+1