Re: max_connections proposal

Craig Ringer <craig(at)postnewspapers(dot)com(dot)au> writes:
> On 05/26/2011 09:48 PM, Tom Lane wrote:
>> Craig Ringer<craig(at)postnewspapers(dot)com(dot)au> writes:
>>> max_connections = 100 # (change requires restart)
>>> # WARNING: If you're about to increase max_connections above 100, you
>>> # should probably be using a connection pool instead. See:
>>> # http://wiki.postgresql.org/max_connections

>> This gives the impression that performance is great at 100 and falls off
>> a cliff at 101, which is both incorrect and likely to lower peoples'
>> opinion of the software.

> Fair call; the use of a specific value is misleading.

>> I'd suggest wording more like "if you're
>> considering raising max_connections into the thousands, you should
>> probably use a connection pool instead".

> Best performance is often obtained with the number of _active_
> connections in the 10s to 30s on commonplace hardware. I'd want to use
> "hundreds" - because mailing list posts etc suggest that people start
> running into problems under load at the 400-500 mark, and more
> importantly because it's well worth moving to pooling _way_ before that
> point.

OK, maybe word it as "If you're considering raising max_connections much
above 100, ..." ?

regards, tom lane