Re: How can I to solute this problem? - Mailing list pgsql-sql

Hi,Thank your help yesterday.

Now I met a new question.
When I continued to clicking UI(jsp) some time, I will get a error in page.It is "Http 404" and Exception is
"NullPoinerExcaption".

I checked the log of tomcat. It recorded a message"connected database failed. The user perporty is missing. It is
mandoatory".

netstat | grep postgres |wc -l
The connection number is 278

lsof -i :5432 | wc -l
60

How can I solute this problem?
Is there bug in postgresql's jdbc?

Could you give me help?

Best regards                                         leon                             2003-07-30

----- Original Message ----- 
From: "Paul Thomas" <paul@tmsl.demon.co.uk>
To: "Achilleus Mantzios" <achill@matrix.gatewaynet.com>
Cc: "LEON" <ldai@accunettech.com>; "pgsql-sql @ postgresql . org" <pgsql-sql@postgresql.org>
Sent: Tuesday, July 29, 2003 8:37 PM
Subject: Re: [SQL] How can I to solute this problem?


> On 29/07/2003 17:09 Achilleus Mantzios wrote:
> > 
> > You may take a look at jboss connection pool
> > mechanism. (postgresql.xml)
> 
> He doesn't mention JBoss, just Tomcat so I don't believe the 
> postgresql.xml will help him much. He could use Tomcat's built-in 
> connection pooling 
> (http://jakarta.apache.org/tomcat/tomcat-4.1-doc/jndi-datasource-examples-howto.html) 
> but should note that there is an error in the web.xml fragment: 
> <res-ref-name>jdbc/mydb</res-ref-name> should be 
> <res-ref-name>jdbc/postgres</res-ref-name>. Leon, if you need more help 
> please feel free to contact me off-list.
> 
> > 
> > Also a good way of ensuring that your app will
> > not leave open stale postgresql connections
> > is to initially configure your pool to only have a small
> > number of connections (e.g. 2,3).
> 
> Good advice for any form of connection pooling.
> 
> > 
> > If your J2EE components (e.g. jsps) are fast enough
> > you should start facing connection shortages
> > only after the load on your machine increases
> > significantly. (and then safely increase the maximum
> > number of connections in your configuration (both postgresql wise
> > and app server (conn pool) wise).
> > 
> > 
> > On Tue, 29 Jul 2003, Paul Thomas wrote:
> > 
> > >
> > > On 29/07/2003 07:18 LEON wrote:
> > > > I use tomcat+linux_postgresql+jsp to develop system.
> > > >
> > > > I start postgresql with 1024 processes.
> > > > FE:
> > > > postmaster -i -S -N 1024 -B 2048 -D /var/lib/pgsql/data
> > > >
> > > > My jsp doesn't implement connection pool.It directly connects
> > postgresql
> > > > by jdbc.
> > >
> > > IME, that is not a good way to do it. Use a connection pool.
> > >
> > > > After I run the Ui some times, the UI(jsp) would report "ieSorry,too
> > many
> > > > clientslg" .The exception is SQLException.
> > > >
> > > > I must restart tomcat or postgresql I can continue to running my UI.
> > >
> > > My guess would be that you have a bug in your application which is not
> > > always closing the connection so eventually you exceed max_connections.
> > 
> > > You should always close the connection in a finally{} block so that is
> > > guaranteed that it will be closed regardless of any earlier exceptions
> > > which are thrown.
> > >
> > > HTH
> > >
> > >
> > 
> > --
> > ==================================================================
> > Achilleus Mantzios
> > S/W Engineer
> > IT dept
> > Dynacom Tankers Mngmt
> > Nikis 4, Glyfada
> > Athens 16610
> > Greece
> > tel:    +30-210-8981112
> > fax:    +30-210-8981877
> > email:  achill at matrix dot gatewaynet dot com
> >         mantzios at softlab dot ece dot ntua dot gr
> > 
> > 
> > ---------------------------(end of broadcast)---------------------------
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> > 
> >                http://archives.postgresql.org
> > 
>