>> If you aren't using pooled
>> connections, maybe you just have more users on the web.
>
> But is there really that number of backends/connections present?
Assuming there is no connection pooling going on, then yes, it is reasonable
to assume that more users means more connections. (I don't know whether DBI
has pooling built-in.)
> I see that error message in storage/ipc/sinval.c (7.2.3) so it
> could be some
> sort kernel limit on shared memory connections or something like that.
Nope, this is definitely a message from the postgresql backend. I'm
embarrassed to admit how many times I've seen it....
FATAL 1: Sorry, too many clients already