Re: Listen / Notify rewrite

Joachim Wieland wrote:
> On Thu, Nov 12, 2009 at 1:04 AM, Andrew Chernow <ac(at)esilo(dot)com> wrote:
>> I think a bsearch would be needed. Very busy servers that make heavy use of
>> notifies would be quite a penalty.
>
> In such an environment, how many relations/channels is a backend
> typically listening to?
> Do you have average / maximal numbers?
>

We have a system where many libpq clients, ~2000 - 4000 per server (depends on
hardware), maintain a persistent backend connection. Each connection listens
for notifies, LISTEN 'client_xxx'. There are maybe 10 different reasons why a
NOTIFY 'client_xxx' is fired. Sometimes, notifies are broadcasted to all client
connections, or just portions of them.

The goal is real-time messaging to a large groups of computers/devices. Past
4000, the problem is distributed to a second, third, etc... server.

--
Andrew Chernow
eSilo, LLC
every bit counts
http://www.esilo.com/