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recommendations for web/db connection pooling or DBD::Gofer reviews
5+ messages / 4 participants
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* recommendations for web/db connection pooling or DBD::Gofer reviews
@ 2008-04-07 18:36 Mark Stosberg <mark@summersault.com>
  2008-04-07 18:44 ` Re: recommendations for web/db connection pooling or DBD::Gofer reviews Joshua D. Drake <jd@commandprompt.com>
  2008-04-08 22:40 ` Re: recommendations for web/db connection pooling or DBD::Gofer reviews PFC <lists@peufeu.com>
  0 siblings, 2 replies; 5+ messages in thread

From: Mark Stosberg @ 2008-04-07 18:36 UTC (permalink / raw)
  To: pgsql-performance


When traffic to our PostgreSQL-backed website spikes, the first resource
we see being exhausted is the DB slots on the master server (currently
set to about 400).

I expect that as new Apache/mod_perl children are being put to us, they
are creating new database connections.

I'm interested in recommendations to funnel more of that traffic through
  fewer DB slots, if that's possible. (We could also consider increasing
the handles available, since the DB server has some CPU and memory to
spare).

I'm particularly interested in review of DBD::Gofer, which seems like it
would help with this in our Perl application:
http://search.cpan.org/dist/DBI/lib/DBD/Gofer.pm

I realize it has limitations, like "no transactions", but I think we
would still able to use it selectively in our application.

    Mark




^ permalink  raw  reply  [nested|flat] 5+ messages in thread

* Re: recommendations for web/db connection pooling or DBD::Gofer reviews
  2008-04-07 18:36 recommendations for web/db connection pooling or DBD::Gofer reviews Mark Stosberg <mark@summersault.com>
@ 2008-04-07 18:44 ` Joshua D. Drake <jd@commandprompt.com>
  1 sibling, 0 replies; 5+ messages in thread

From: Joshua D. Drake @ 2008-04-07 18:44 UTC (permalink / raw)
  To: Mark Stosberg <mark@summersault.com>; +Cc: pgsql-performance

On Mon, 07 Apr 2008 14:36:00 -0400
Mark Stosberg <mark@summersault.com> wrote:

 
> I'm particularly interested in review of DBD::Gofer, which seems like
> it would help with this in our Perl application:
> http://search.cpan.org/dist/DBI/lib/DBD/Gofer.pm
> 
> I realize it has limitations, like "no transactions", but I think we
> would still able to use it selectively in our application.

I would stick to proven postgresql technologies such as pgbouncer.

Sincerely,

Joshua D. Drake


> 
>     Mark
> 
> 


-- 
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^ permalink  raw  reply  [nested|flat] 5+ messages in thread

* Re: recommendations for web/db connection pooling or DBD::Gofer reviews
  2008-04-07 18:36 recommendations for web/db connection pooling or DBD::Gofer reviews Mark Stosberg <mark@summersault.com>
@ 2008-04-08 22:40 ` PFC <lists@peufeu.com>
  2008-04-10 21:28   ` Re: recommendations for web/db connection pooling or DBD::Gofer reviews Mark Stosberg <mark@summersault.com>
  1 sibling, 1 reply; 5+ messages in thread

From: PFC @ 2008-04-08 22:40 UTC (permalink / raw)
  To: Mark Stosberg <mark@summersault.com>; pgsql-performance


> When traffic to our PostgreSQL-backed website spikes, the first resource
> we see being exhausted is the DB slots on the master server (currently
> set to about 400).
>
> I expect that as new Apache/mod_perl children are being put to us, they
> are creating new database connections.
>
> I'm interested in recommendations to funnel more of that traffic through
>   fewer DB slots, if that's possible. (We could also consider increasing
> the handles available, since the DB server has some CPU and memory to
> spare).
>
> I'm particularly interested in review of DBD::Gofer, which seems like it
> would help with this in our Perl application:
> http://search.cpan.org/dist/DBI/lib/DBD/Gofer.pm
>
> I realize it has limitations, like "no transactions", but I think we
> would still able to use it selectively in our application.

	Under heavy load, Apache has the usual failure mode of spawning so many  
threads/processes and database connections that it just exhausts all the  
memory on the webserver and also kills the database.
	As usual, I would use lighttpd as a frontend (also serving static files)  
to handle the large number of concurrent connections to clients, and then  
have it funnel this to a reasonable number of perl backends, something  
like 10-30. I don't know if fastcgi works with perl, but with PHP it  
certainly works very well. If you can't use fastcgi, use lighttpd as a  
HTTP proxy and apache with mod_perl behind.
	Recipe for good handling of heavy load is using an asynchronous server  
(which by design can handle any number of concurrent connections up to the  
OS' limit) in front of a small number of dynamic webpage generating  
threads/processes.



^ permalink  raw  reply  [nested|flat] 5+ messages in thread

* Re: recommendations for web/db connection pooling or DBD::Gofer reviews
  2008-04-07 18:36 recommendations for web/db connection pooling or DBD::Gofer reviews Mark Stosberg <mark@summersault.com>
  2008-04-08 22:40 ` Re: recommendations for web/db connection pooling or DBD::Gofer reviews PFC <lists@peufeu.com>
@ 2008-04-10 21:28   ` Mark Stosberg <mark@summersault.com>
  2008-04-11 14:41     ` Re: recommendations for web/db connection pooling or DBD::Gofer reviews Vivek Khera <vivek@khera.org>
  0 siblings, 1 reply; 5+ messages in thread

From: Mark Stosberg @ 2008-04-10 21:28 UTC (permalink / raw)
  To: pgsql-performance


>     Under heavy load, Apache has the usual failure mode of spawning so 
> many threads/processes and database connections that it just exhausts 
> all the memory on the webserver and also kills the database.
>     As usual, I would use lighttpd as a frontend (also serving static 
> files) to handle the large number of concurrent connections to clients, 
> and then have it funnel this to a reasonable number of perl backends, 
> something like 10-30. I don't know if fastcgi works with perl, but with 
> PHP it certainly works very well. If you can't use fastcgi, use lighttpd 
> as a HTTP proxy and apache with mod_perl behind.
>     Recipe for good handling of heavy load is using an asynchronous 
> server (which by design can handle any number of concurrent connections 
> up to the OS' limit) in front of a small number of dynamic webpage 
> generating threads/processes.

Thanks for the response.

To be clear, it sounds like you are advocating solving the problem with 
scaling the number of connections with a different approach, by limiting 
the number of web server processes.

So, the front-end proxy would have a number of max connections, say 200, 
  and it would connect to another httpd/mod_perl server behind with a 
lower number of connections, say 20. If the backend httpd server was 
busy, the proxy connection to it would just wait in a queue until it was 
available.

Is that the kind of design you had in mind?

That seems like a reasonable option as well. We already have some 
lightweight Apache servers in use on the project which currently just 
serve static content.

    Mark




^ permalink  raw  reply  [nested|flat] 5+ messages in thread

* Re: recommendations for web/db connection pooling or DBD::Gofer reviews
  2008-04-07 18:36 recommendations for web/db connection pooling or DBD::Gofer reviews Mark Stosberg <mark@summersault.com>
  2008-04-08 22:40 ` Re: recommendations for web/db connection pooling or DBD::Gofer reviews PFC <lists@peufeu.com>
  2008-04-10 21:28   ` Re: recommendations for web/db connection pooling or DBD::Gofer reviews Mark Stosberg <mark@summersault.com>
@ 2008-04-11 14:41     ` Vivek Khera <vivek@khera.org>
  0 siblings, 0 replies; 5+ messages in thread

From: Vivek Khera @ 2008-04-11 14:41 UTC (permalink / raw)
  To: pgsql-performance


On Apr 10, 2008, at 5:28 PM, Mark Stosberg wrote:
> So, the front-end proxy would have a number of max connections, say  
> 200,  and it would connect to another httpd/mod_perl server behind  
> with a lower number of connections, say 20. If the backend httpd  
> server was busy, the proxy connection to it would just wait in a  
> queue until it was available.

If you read the mod_perl performance tuning guide, it will tell you to  
do exactly this.  These are solved problems for many, many years now.   
The apache mod_proxy really does wonders...




^ permalink  raw  reply  [nested|flat] 5+ messages in thread


end of thread, other threads:[~2008-04-11 14:41 UTC | newest]

Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2008-04-07 18:36 recommendations for web/db connection pooling or DBD::Gofer reviews Mark Stosberg <mark@summersault.com>
2008-04-07 18:44 ` Joshua D. Drake <jd@commandprompt.com>
2008-04-08 22:40 ` PFC <lists@peufeu.com>
2008-04-10 21:28   ` Mark Stosberg <mark@summersault.com>
2008-04-11 14:41     ` Vivek Khera <vivek@khera.org>

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