"Gnanakumar" <gnanam(at)zoniac(dot)com> wrote:
> I've already thought of converting this into a document and keep
> it handy so that I may want to refer back whenever I need.
I've put up a first cut at such a document as a Wiki page:
http://wiki.postgresql.org/wiki/Number_Of_Database_Connections
Everyone should feel free to improve upon it. I'll probably add a
"thought experiment" I've used a few times which seems to help some
people understand the issue.
>> A formula which has held up pretty well across a lot of
>> benchmarks for years is that for optimal throughput the number of
>> active connections should be somewhere near
>> ((core_count * 2) + effective_spindle_count).
>
> Our entire Production application stack is setup in Amazon EC2
> cloud environment, that includes database server also. So, in
> that case, how do I find out "effective_spindle_count"? I know
> "core_count" can be determined from Amazon EC2 instance type. Per
> Amazon EC2, EBS volumes are reportedly a shared resource.
I think you need to experiment with different pools sizes. Please
post results and/or update the Wiki page.
-Kevin