Re: idle processes - pg_recvbuf

Josh,

Couple of things:
1) you only need to load the driver once ie only do the Class.forName
once
2) you should close the connection in a finally

ie try{
get connection
}catch()
{
handle your error
}
finally
{
close connection
}

3) now that being said, you should actually cache your connections

4) close the connections in the cache from the destroy() method in the
servlet

Dave
On Fri, 2002-11-08 at 13:43, Josh Trutwin wrote:
> Hello list,
>
> I am rather new to JDBC programming with postgresql (making the switch
> from PhP/MySQL). I recently created a web application for learning
> JDBC/postgresql for an online links database (how's that for reinventing
> the wheel?)
>
> Anyway, I am noticing some odd problems, every now and then I see the
> following message on my server:
>
> DEBUG: pq_recvbuf: unexpected EOF on client connection
>
> Searching google for this doesn't provide many answers. Some posts on the
> postgres lists, but no concrete answers. Hopefully this time...
>
> I also see an increasing number of idle connection when doing:
>
> ps -deaf | grep postgres
>
> At the moment I have 10 idle processes.
>
> I am using postgresql version 7.2.2 and tomcat 4.1.12 with Java 1.4.1 on
> SuSE 7.3. My pgjdbc2.jar is dated Sept. 24th, no idea on the version
> number.
>
> I designed a database utilities class so I could have all my queries in
> one spot. I think this is the culprit, but I am not sure. Here is part
> of the code:
>
> import blah blah blah;
>
> public class DBUtils extends HttpServlet {
> private java.sql.Connection connection;
> private PrintWriter out;
>
> public DBUtils (HttpServletResponse response) {
> try {
> out = response.getWriter();
>
> Class.forName("org.postgresql.Driver").netInstance();
> connection = DriverManager.getConnection(
> "jdbc:postgresql://localhost/mydb", "me", "mypass");
>
> } catch (SQLException sqle) and so on
> }
>
> public void finalize() throws java.lang.Throwable {
> try {
> connection.close();
> } catch (SQLException sqle) {
> out.println("Error closing connection" + sqle);
> }
> }
>
> public ArrayList getLinks () {
> // query db, return array
> }
> }
>
> It would seem that my finalize routine is being called most of the time,
> but not all of the time. Do other users have a better way of doing this?
> I want to keep all my query stuff seperate from the presentation layer,
> but I also want to close every connection cleanly. This is coming from
> normal use (e.g. I didn't kill the browser in the middle of a query or
> something).
>
> Thanks in advance,
>
> Josh Trutwin
> http://trutwins.homeip.net
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo(at)postgresql(dot)org
--
Dave Cramer <Dave(at)micro-automation(dot)net>