Re: Decrease MAX_BACKENDS to 2^16

On 04/26/2014 11:06 AM, David Fetter wrote:
> I know we allow for gigantic numbers of backend connections, but I've
> never found a win for >2x the number of cores in the box, which at
> least in my experience so far tops out in the 8-bit (in extreme cases
> unsigned 8-bit) range.

For my part, I've found that anything over a few hundred backends on a
commodity server leads to serious performance degradation.  Even 2000 is
enough to make most servers fall over.  And with proper connection
pooling, I can pump 30,000 queries per second through about 45
connections, so the clear path to supporting large numbers of
connections is some form of built-in pooling.

However, I agree with Tom that Andres should "show his hand" before we
decrease MAX_BACKENDS by 256X.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com