Обсуждение: Windows max concurrent connections

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Windows max concurrent connections

От
"Mario Ferloni"
Дата:
Hi all,

this is my very first post to this list. I have searched the archives,
but it seems that this argument hasn't been treated deeply before.
Please be fair as this will be a long message :) .
I am in charge of designing and implementing a medium-size deployment
of PostgreSQL (with PostGIS), with the following requirements:
* OS: Windows 2003 R2 x64 (two nodes with fibre channel shared storage)
* Cluster: Microsoft Clustering

I will be using the 8.3.1 version of PostgreSQL (32bit).

I already have built a simple lab on vmware to test postgresql with ms
clustering and everything seems to work fine.

I am a bit concerned about the max concurrent connection problem
documented in the windows faq
(http://www.postgresql.org/docs/faqs.FAQ_windows.html#4.4), that is
due to user32.dll limitations. Now, my question is: what is the status
of this problem as of 8.3.1 version?
Obviously, I am not going to start PostgreSQL from the commandline
(cluster services requires it to be started as a service), so the
problem is going to be a major problem, since I expect a larger number
of concurrent connections, due to the expected usage of the db.

I would like to discuss with you some scenarios and how (and possibly
if) can they mitigate this problem.

scenario 1:
Microsoft cluster services allow to start a generic service as a
clustered resource, but allow to start a generic application also. It
seems that the problem could be avoided this way, since starting pgsql
as an application will mitigate the problem, *but* this would be
started by the cluster service, so maybe the problem will be the
same... anyone tested it this way?
scenario 2:
I will be using postgresql on a x64 os, but I am going to use the
32bit precompiled version of postgresql, since (as I read on
http://people.planetpostgresql.org/mha/index.php?/archives/162-PostgreSQL-vs-64-bit-windows.html)
apparently there wont' be any big advantages to have a 64bit version o
postgresql, due to the way it has been developed. My question is: on a
x64 OS libraries used by postgresql will again use user32.dll (due to
the fact the app is a 32bit app) or will they use the 64bit version of
user32.dll (which, I suppose, has not the limitation of the 32-bit
version?).
scenario 3:
if the previous scenario is not successful, will a x64 version of
postgresql solve the problem? I expect the answer will be yes, but I
see that such a port not only does not exist, but that isn't planned
either... anyone has tried that?
scenario 4:
this solution based on Interix
(http://people.planetpostgresql.org/merlin/index.php?/archives/1-64-bit-PostgreSQL-on-windows-read-on....html).
Anyone tested it on a true x64 box?

I know that this is a bunch of questions, but I hope that someone will
put me on the right way... :)

Thank you in advance,
--
MF

Re: Windows max concurrent connections

От
"Scott Marlowe"
Дата:
On Thu, Apr 3, 2008 at 10:11 AM, Mario Ferloni <m.ferloni@gmail.com> wrote:
>
>  I am a bit concerned about the max concurrent connection problem
>  documented in the windows faq
>  (http://www.postgresql.org/docs/faqs.FAQ_windows.html#4.4), that is
>  due to user32.dll limitations. Now, my question is: what is the status
>  of this problem as of 8.3.1 version?

Have you looked into connection pooling?

Re: Windows max concurrent connections

От
"Benjamin Krajmalnik"
Дата:
Assuming he is using ODBC to connect, I do not believe the current ODBC
driver supports connection pooling.
My experience was that it did not.  I posted a question on the ODBC
list, but have not yet received a reply.


> -----Original Message-----
> From: pgsql-admin-owner@postgresql.org
> [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of Scott Marlowe
> Sent: Thursday, April 03, 2008 10:47 AM
> To: Mario Ferloni
> Cc: pgsql-admin@postgresql.org
> Subject: Re: [ADMIN] Windows max concurrent connections
>
> On Thu, Apr 3, 2008 at 10:11 AM, Mario Ferloni
> <m.ferloni@gmail.com> wrote:
> >
> >  I am a bit concerned about the max concurrent connection problem
> > documented in the windows faq
> > (http://www.postgresql.org/docs/faqs.FAQ_windows.html#4.4),
> that is
> > due to user32.dll limitations. Now, my question is: what is
> the status
> > of this problem as of 8.3.1 version?
>
> Have you looked into connection pooling?
>
> --
> Sent via pgsql-admin mailing list
> (pgsql-admin@postgresql.org) To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-admin
>

Re: Windows max concurrent connections

От
"Mario Ferloni"
Дата:
Hi,

(reposting... I replied directly to sender instead than to the mailing list...)

On Thu, Apr 3, 2008 at 6:47 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
> On Thu, Apr 3, 2008 at 10:11 AM, Mario Ferloni <m.ferloni@gmail.com> wrote:
> >
> >  I am a bit concerned about the max concurrent connection problem
> >  documented in the windows faq
> >  (http://www.postgresql.org/docs/faqs.FAQ_windows.html#4.4), that is
> >  due to user32.dll limitations. Now, my question is: what is the status
> >  of this problem as of 8.3.1 version?
>
> Have you looked into connection pooling?
>


mmm... I have done a little searching about it (consider I am a bit
new to the pg world :) ):
* pgpool-II is not supported under windows. anyone has experience on it?
* pgbouncer? but the user.txt file...
* memcache seems to me to be not a viable solution (requires rewriting
any app to make use of it...)

or... is there anybody out there that faced the same problem? how do
you managed to solve it? can you point me to some documentation about
connection pooling?

thanks in advance!

best regards,
--
MF