Re: Increase in max_connections - Mailing list pgsql-general

From John R Pierce
Subject Re: Increase in max_connections
Date
Msg-id 531F6CC1.6070809@hogranch.com
Whole thread Raw
In response to Re: Increase in max_connections  ("Anand Kumar, Karthik" <Karthik.AnandKumar@classmates.com>)
Responses Re: Increase in max_connections  ("Anand Kumar, Karthik" <Karthik.AnandKumar@classmates.com>)
List pgsql-general
On 3/11/2014 10:20 AM, Anand Kumar, Karthik wrote:
> We typically see about 500-700 active queries at a time

if these are primarily small/fast queries, like OLTP operations, and you
DONT have 200-400 CPU cores on this server, you will likely find that if
you use a queueing mechanism to only execute about 2X your CPU core
count concurrently, you will get MORE total transactions/second than
trying to do 500-700 at once.

if your apps are using persistent connections, then the session pooling
model won't do any good, you should use transaction pooling.  you want
the actual active query count to be tunable, probably down around 2X the
cpu core count, depending on various things.    some folks say, CPU
cores/threads plus disk spindles is the optimal number.



--
john r pierce                                      37N 122W
somewhere on the middle of the left coast



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