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From sasidhar prabhakar <sasidhar1...@gmail.com>
Subject Re: DBCP abandoned trace - unable to understand the leak
Date Wed, 10 Nov 2010 06:51:37 GMT
After changing time out value now I am getting this problem

org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot get a connection,
pool error Timeout waiting for idle object





On Tue, Nov 9, 2010 at 5:22 PM, Christopher Schultz <
chris@christopherschultz.net> wrote:

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> Sasidhar,
>
> On 11/8/2010 12:31 AM, sasidhar prabhakar wrote:
> > On Thu, Nov 4, 2010 at 9:10 PM, Christopher Schultz <
> > chris@christopherschultz.net> wrote:
> >>
> >> I have found that these exceptions can occur even when there is no leak.
> >>
> >> Specifically, if your SQL query takes a long time to run (that is, more
> >> than the ababdonedTimeout), another request to the connection pool
> >> complains about the connection and calls it abandoned.
> >>
> >
> > I think your right. Timeout  I mentioned 30sec deafault is 300sec. This
> is
> > my context.xml
>
> > <?xml version="1.0" encoding="UTF-8"?>
> > <Context path="" >
>
> "path" is not allowed in context.xml: remove it.
>
> > validationQuery="SELECT * from dual"
>
> SELECT *? Wow. How about "SELECT 1 FROM dual"?
>
> > testOnBorrow="true"
> > removeAbandoned="true"
> > removeAbandonedTimeout="30"
>
> That's a 30-second abandoned timeout.
>
> > username="scott"
> > password="*******"
>
> "tiger", right?
>
> >> Technically speaking, the connection hasn't been leaked, but the
> >> connection pool can't really guess the reason why the connection hasn't
> >> been returned.
> >>
> >> Can you time your queries to see how long they take? Could you post your
> >> <Resource> configuration for your DataSource?
> >
> > For some queries it took more than 30 seconds, from getting data from
> > ip_to_geo table, which has 3 million rows in it.
>
> That could be your problem: you should probably increase your
> removeAbandonedTimeout value to something more appropriate for your
> application.
>
> You might also want a dba to check out your queries and your database
> structure. 3 million rows isn't that much, even for Oracle :)
>
> >> Another note: I notice that you are using a DataSource object that
> >> survives for the life of the DAO object, and is even created by the
> >> object in its constructor.
> >
> > Every DAO has only one instance for the entire life of application. Is
> this
> > correct approach. So Every thread accessing the same datasource object to
> > get connection.
>
> It was just a recommendation which gives you flexibility: your webapp
> (or the container, etc.) has the freedom to discard and completely
> re-build the DataSource for your webapp if you always go to the JNDI
> context to get the DataSource. Otherwise, you will force a webapp
> restart just to get a new DataSource.
>
> - -chris
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