1 Reply Latest reply on Jun 11, 2003 6:54 PM by Jon Barnett

    ManagedConnectionPool.  Value of MinSize.

    Nigel Birch Newbie


      I'm using JBoss 3.0.2 with PostgreSQL7.3.1 on Linux.

      In the postgres-service.xml file the ManagedConnectionPool MBean has the MinSize attribute set to 0. So does this mean that a new connection to the database is established every time JBoss needs to talk to it??

      I read that defining a minimum size for the connection pool would increase
      performance, but I changed MinSize to 10 and saw no change in performance.

      Can someone explain how to configure this connection pool properly?


        • 1. Re: ManagedConnectionPool.  Value of MinSize.
          Jon Barnett Master

          It means at the start of the container lifecycle, the pool will be at 0. As load increases, the connection pool will grow according to demand. Eventually, if enough time passes without a call to a particular connection, that connection will 'reaped'. This will continue until the pool shrinks back to 0. It would only shrink back to 0 if there are no requests for that connection for the lifetime of that connection. The template examples give you all the control parameters for a connection pool.

          The connection pool will increase your performance under steady state load and give you an advantage on ramp up. That is balanced against the cost of maintaining x open connections to your DB. On postgresql, you can monitor the number of connections (postmaster processes when doing a ps).