Re: PGconn thread safety

Поиск
Список
Период
Сортировка
От ahoward
Тема Re: PGconn thread safety
Дата
Msg-id Pine.LNX.4.33.0302071441580.20779-100000@eli.fsl.noaa.gov
обсуждение исходный текст
Ответ на Re: PGconn thread safety  (Lee Kindness <lkindness@csl.co.uk>)
Список pgsql-general
On Fri, 7 Feb 2003, Lee Kindness wrote:

> Well the areas I have patched would have /potentially/ caused
> inaccurate error messages (using global errno). Also potential
> corruption on connect to database if 2+ threads were trying to do this
> at once - a non-threadsafe fucntion was being used to retrieve all
> local usernames.
>
> I've been a bit busy of late, the code itself is submitted to
> pgsql-patches but configure work is still to be done.
>
> L.


in my connection pool, all connections are made _before_ any thread access
takes place.  the pool will be used mostly for cgi programs so i really don't
care about error messages too much (seems like using res = PGExec might fix
this issue?) so it seems like my application may not need thread protection.

-a


>
> Shridhar Daithankar writes:
>  > On Friday 07 February 2003 12:44 pm, you wrote:
>  > > Neil Conway <neilc@samurai.com> writes:
>  > > That's the theory anyway.  I believe it actually is free of unsafe uses
>  > > of static variables.  However, someone recently pointed out that it uses
>  > > some libc routines that probably aren't thread-safe; so there's some
>  > > cleanup yet to do before we can claim real thread safety.
>  >
>  > Well, I ran a mutlithreaded test where around 30 connections were hammered in
>  > a mutlihtreaded servers using libpq for 100,000 transactions. I didn't notice
>  > any data inconsistency.
>  >
>  > Only noticable thing was that postgresql was not returning even simplest
>  > result in less than 200 ms. So in order to achieve a good throughput, I had
>  > to up the number of connections. The max throughput. was 200ms/no. of
>  > connections.
>  >
>  > but that is a different issue..
>  >
>  >  Shridhar
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: Have you searched our list archives?
>
> http://archives.postgresql.org
>

--

 ====================================
 | Ara Howard
 | NOAA Forecast Systems Laboratory
 | Information and Technology Services
 | Data Systems Group
 | R/FST 325 Broadway
 | Boulder, CO 80305-3328
 | Email: ahoward@fsl.noaa.gov
 | Phone:  303-497-7238
 | Fax:    303-497-7259
 ====================================


В списке pgsql-general по дате отправления:

Предыдущее
От: ahoward
Дата:
Сообщение: Re: PGconn thread safety
Следующее
От: Tom Lane
Дата:
Сообщение: Re: Database access problem : SOS