Re: Proposal of tunable fix for scalability of 8.4

On Thu, 12 Mar 2009, Jignesh K. Shah wrote:

> As soon as I get more "cycles" I will try variations of it but it would
> help if others can try it out in their own environments to see if it
> helps their instances.

What you should do next is see whether you can remove the bottleneck your
test is running into via using a connection pooler. That's what I think
most informed people would do were you to ask how to setup an optimal
environment using PostgreSQL that aimed to serve thousands of clients.
If that makes your bottleneck go away, that's what you should be
recommending to customers who want to scale in this fashion too. If the
bottleneck moves to somewhere else, that new hot spot might be one people
care more about. Given that there are multiple good pooling solutions
floating around already, it's hard to justify dumping coding and testing
resources here if that makes the problem move somewhere else.

It's great that you've identified an alternate scheduling approach that
helps on your problematic test case, but you're a long ways from having a
full model of how changes to the locking model impact other database
workloads. As for the idea of doing something in this area for 8.4, there
are a significant number of performance-related changes already committed
for that version that deserve more focused testing during beta. You're
way too late to throw another one into that already crowded area.

--
* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD