Hi Chris, thanks for the comments. I thought since we have singleton class and
creating a connection object there, we will be reusing the same connection
object for all database operations. May be my thinking is not correct. Do you
suggest I just create the DataSource object in the private constructor and then
get connection object from the datasource when doing a
database query/update opeartions? Yes, I will make sure I close the stmt and
connection objects.
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private static DataSource ds = null;
private DBManager() throws Exception
{
Context init = new InitialContext();
Context ctx = (Context) init.lookup("java:comp/env");
ds = (DataSource) ctx.lookup("jdbc/jalasevaDB");
}
And then, for example, in a method to do query,
myCon = ds.getConnection();
stmt = myCon.createStatement();
And then close the stmt and mycon.
-------
What would be the effect of calling 'ds.getConnection()' for every database
operation?
Thanks again for your guidance,
Seetha
-----Original Message-----
From: Christopher Schultz [mailto:[EMAIL PROTECTED]
Sent: Sunday, July 23, 2006 8:04 PM
To: [EMAIL PROTECTED]
Cc: Tomcat Users List; [EMAIL PROTECTED]
Subject: Re: Tomcat fails to refresh connections when mySQL server on
linux is shutdown and restarted
Seetha,
> To answer Tim's question, we are not explicitly closing connection
> and statement objects as the context xml has these resource parameters.
>
> removeAbandoned="true"
> removeAbandonedTimeout="60"
> logAbandoned="true"
This probably means that you are leaking every single connection. :(
> Shouldn't DBCP take care of creating new connection if the connection
> object is stale?
You will be creating new Connection objects all the time -- basically
you'll never re-use a database connection, making the pool completely
irrelevant; you may as well call DriverManager.getConnection each time
you need to make a SQL query.
Even if DBCP /does/ clean up after you, you /really/ need to call
"close" on your statement, resultset, and connection objects in finally
blocks in your code. If you don't, your code will probably not work
if/when you switch to another connection pool, another app server,
another database, etc.
Most databases allocate lots of memory for each database connection on
the server side, which means that every useless connection you have
waiting around to be cleaned up by DBCP will be taking up memory on your
database server that could be used to serve actual requests.
Whether this solves your original problem or not, you definitely need to
modify your code to close all of those objects.
-chris
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