[Proxool-developer] Forum Entry: Shutting down Proxool

[Bill H. <bi...@lo...>]

By: zyzgy ( Jason Oh ) 
shutting down proxool   
2003-11-20 15:31 
hello,
i have a trivial question. just started using proxool and am not sure
about how to shutdown the proxool connection pool. i can close all the
connections manually (conn.close()), but don't know if it is up to me to
shutdown the proxool pool. i've noticed that there is a shutdown hook
which starts when the application exits--does this take care of
connection pool cleanup at application exit?

thanks for your help! 


        By: billhorsman ( Bill Horsman ) 
        RE: shutting down proxool   
        2003-11-20 15:41 
        Hi Jason,
        
        It depends in what environment you are running Proxool... if
        it's an application running in it's own JVM and you're using JDK
        1.3 or later then the ShutdownHooks will do exactly what you
        want. 
        
        JDK 1.2 doesn't support ShutdownHooks, in which case you should
        call ProxoolFacade.shutdown() explicitly.
        
        If you are running Proxool in something like a servlet container
        (e.g. JBoss, Resin) then you need to explicitly shutdown too -
        otherwise if you redeploy you end up with two instances of
        Proxool (the JVM doesn't call the shutdown hooks on a redeploy).
        In that case, you also need to call shutdown() explicitly.
        Normally in a servlet's destroy() method. Alternatively, use the
        ServletConfigurator and it will do it for you.
        
        Just to make sure you are using the pool correctly: you call
        conn.close() after every database action right? You shouldn't
        leave them open until the application is shutting down - that is
        what Proxool does for you.
        
        Cheers,
        Bill Horsman 
        
        
        By: zyzgy ( Jason Oh ) 
        RE: shutting down proxool   
        2003-11-20 16:03 
        hi bill,
        thanks for your prompt response! yes, i'm currently running
        jdk1.4.2 in a testing environment (command-line) and will have
        to migrate everything to a servlet container soon (tomcat4). i
        call conn.close() immediately after every db call currently.
        
        so, in the context of a servlet container, you mention that
        shutdown() must be called explicitly. i use the DriverManager to
        getConnection() and use the proxool PropertyConfigurator to
        initialize proxool. on which object must i invoke shutdown()
        once i move to tomcat?
        
        also, i'm thinking that i will have to use transactions as part
        of my app. do you have any suggestions/ideas with respect to the
        best way to use transactions in concert with proxool?
        
        thanks again for your help,
        jason 
        
        
        By: billhorsman ( Bill Horsman ) 
        RE: shutting down proxool   
        2003-11-20 16:32 
        Hi Jason,
        
        Take a look here:
        http://proxool.sourceforge.net/servlets.html
        
        It tells you how to use the ServletConfigurator to automatically
        configure Proxool using a properties file. The benefits of which
        are:
        
        1) No Proxool code in your app, just some lines in web.xml
        
        2) ServletConfigurator will automatically call
        ProxoolFacade.shutdown() in its destroy() method.
        
        In answer to your specific question about calling shutdown().
        You use ProxoolFacade.shutdown(). It's a static method, so no
        object needed.
        
        As far as transactions go, Proxool treats them transparently.
        That is, you use them exactly as you would with no connection
        pool: open the connection at the start of the transaction, close
        the connection at the end of the transaction.
        
        Cheers,
        Bill
        
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