Thanks Jason! I am taking time to think about how to integrate your nice solution with "my transparency".
Regards, Jason R Lee wrote: > > Well, actually wouldn't a connection pool object be responsible for handling the >datasource when it creates the pools? > > Oh, I see what your saying. You have a datasource factory that you want to be >available to have pools and other connections join/unjoin from it, correct? > > This approach should work with DBCP as long as the datasource is not dropped ><correct-if-mistaken/>. I think most of the pooling objects I've worked with thought >couple the datasource creation with the connection object in their framework. I've >never really seen it decoupled like that, but, hey it should still work fine. :) > > - jason > > -----Original Message----- > From: Lev Assinovsky [mailto:[EMAIL PROTECTED]] > Sent: Thu 3/14/2002 9:31 AM > To: Jakarta Commons Developers List > Cc: > Subject: Re: [dbcp] Works with JNDI, but some remarks... > Jason, your explanation is perfect! > Thanks! > I have just one point. > With "my approach" (and BasicDatabaseFactory behind the scene) > application get just DataSource whether it working with pool or without. > If application closes the connection it doesn't know what's going on > further - > the connection is released or physically closed. > So the connection is transparent for application. > It would be nice to join "my approach" and youth. > But I am not sure DBCP is ready for that. > > Thanks again! > > Jason R Lee wrote: > > > > Well, > > > > Here's some sample code for a servlet registration in web.xml: > > > > registers the servlet: > > > > <servlet> > > <servlet-name>dbcpPoolStartup</servlet-name> > > <servlet-class>org.some.servlet.package</servlet-class> > > <init-param> > > <param-name>datasourceURI</param-name> > > <param-value>jdbc:oracle:thin:user/password:1521:sid</param-value> > > </init-param> > > <load-on-startup>1</load-on-startup> > > </servlet> > > > > provides the url mapping: > > > > <servlet-mapping> > > <servlet-name>dbcpPoolStartup</servlet-name> > > <url-pattern>/dbcpPoolStartup</url-pattern> > > </sevlet-mapping> > > > > We'll get more to the servlet specifics in a bit. > > > > there's 2 web.xml files you could put it in, both of which will have different >affects. > > > > If you In your $TOMCAT_HOME/conf/web.xml, then this will load when the Tomcat >container starts. If you have multiple webapps that happen to use the same db >connection, database, etc., then this would be beneficial. However, if you do have >multiple webapps using a database, then they prob have separate tables, so the above >probably wouldn't work to well. However, you could make a servlet that accepted >multiple parameters for different datasourceURI's. > > > > example: > > > > <init-param> > > <param-name>shoppingDatasourceURI</param-name> > > <param-value>jdbc:oracle:thin:shopuser/password:1521:sid</param-value> > > </init-param> > > <init-param> > > <param-name>portalDatasourceURI</param-name> > > <param-value>jdbc:oracle:thin:portaluser/password:1521:sid</param-value> > > </init-param> > > <init-param> > > <param-name>emailDatasourceURI</param-name> > > <param-value>jdbc:oracle:thin:emailuser/password:1521:sid</param-value> > > </init-param> > > > > Right? So on init, the 3 names and values would be passed in and, if you built >your sevlet to deal with that, it could set up 3 different pools for the different >webapps running. This would probably only be the case, tho, if you were to put this >at the container startup level, which is important to understand. > > > > The other web.xml lives in $TOMCAT_HOME/webapps/yourwebapp/WEB-INF. The first >example (the single init value) would work fine at this level. You init one pool for >your entire webapp, which is usually the case. The servlet then would be responsible >for setting up the connection and JNDI info and then scoping it to the appplication >level. > > > > It gets really cool with this stuff because you can basically then build in other >methods into your servlet that could allow it to dynamically switch, at run-time >(altho, that has to be thought out since you would be changing pools and such and >your app might not be too happy about that) allowing you to 'fix', possibly, or >change various potential problems that might crop up. Or switch user names, whatever. >Point is is that a servlet can make a very nice admin tool for >starting/stopping/reloading pool instances as well as anyt other app scoped objects. > > > > One thing to keep in mind, every time the webapp is started there might be a >little lag time associated with the pool and JNDI setup. There's all kinds of tricks >you can use to get around that (i.e. you *could* ;) have a servlet that started at >the Tomcat init level that then went out and init'd your sevlets, but that's another >topic in iteself). > > > > I'm pretty sure this is correct and i remembered everything, but if not, someone >feel free to correct me. So hopefully this helps or provides a little insight. > > > > cheers, > > > > - jason > > > > -----Original Message----- > > From: Lev Assinovsky [mailto:[EMAIL PROTECTED]] > > Sent: Thu 3/14/2002 6:54 AM > > To: Jakarta Commons Developers List > > Cc: > > Subject: Re: [dbcp] Works with JNDI, but some remarks... > > Jason, > > it's pretty interesting what you are saying. I thought about such > > approach but > > I don't have enough knowledge in Tomcat. > > Let me few stupid questions please: > > 1. I can write servlet which will do pool creation and JNDI > > registration. But how to set it up to start it upon init of the > > container? > > 2. How to setup servlet upon init of Tomcat? > > > > Thanks in advance! > > > > Jason R Lee wrote: > > > > > > All users will definitely be application scope. To further that, it would >probably be best to have a servlet, upon init of the container, start the connection >pool and then register it via JNDI. Then your bean would be accessing that instead of >creating it every time they are needed. The whole point behind connection pooling is >for giving multiple objects, usually, over the scope of the application access to >preconneted pools (sorry if this is review). Creating a new pool obj based on a >request level scope pretty much defeats the purpose. > > > > > > I'm actually working on dbcp at this level now. I just have a servlet start the >pool when tomcat starts up. Pretty easy stuff. I'm interested in seeing how well the >pool works vs. just getting a regular connection every time (I'm sure dbcp will smoke >it). > > > > > > cheers, > > > > > > - Jason > > > > > > -----Original Message----- > > > From: Lev Assinovsky [mailto:[EMAIL PROTECTED]] > > > Sent: Thu 3/14/2002 5:23 AM > > > To: Jakarta Commons Developers List > > > Cc: > > > Subject: [dbcp] Works with JNDI, but some remarks... > > > Hello all! > > > I got dbcp working through JNDI in Tomcat 4.0.4b1. > > > Thank you! (I got tired of Tyrex :-)) > > > > > > But I have several issues. > > > > > > My configuration server.xml is: > > > <Resource name="lev/DataSource" auth="Container" > > > type="javax.sql.DataSource"/> > > > <ResourceParams name="lev/DataSource"> > > > <parameter><name>factory</name> > > > > > > <value>org.apache.commons.dbcp.BasicDataSourceFactory</value> > > > </parameter> > > > > > > > > > <parameter><name>username</name><value>wv</value></parameter> > > > > > > <parameter><name>password</name><value>wv</value></parameter> > > > > > > <parameter><name>maxActive</name><value>100</value></parameter> > > > > > > <parameter><name>maxIdle</name><value>30000</value></parameter> > > > > > > <parameter><name>maxWait</name><value>100</value></parameter> > > > <parameter><name>driverClassName</name> > > > <value>org.gjt.mm.mysql.Driver</value></parameter> > > > <parameter><name>url</name> > > > > > > <value>jdbc:mysql://localhost:3306/WV?user=wv&password=wv</value></parameter> > > > </ResourceParams> > > > > > > 1. When I had 'user' instead of 'username' (Tyrex allows both) I got > > > NullPointer exception > > > in connectionProperties.put("user", username) in BasicDataSource. > > > > > > 2. When I didn't have maxActive I got infinite loop in borrowObject() > > > in GenericObjectPool. > > > > > > Actually I don't have clear understanding of the pool's parameters. > > > I'all really appreciate > > > if somebody could make it clear for me. > > > > > > Also with xml parameters above I got very often: > > > > > > java.sql.SQLException: Communication link failure: java.io.IOException > > > at org.gjt.mm.mysql.MysqlIO.clearAllReceive(Unknown Source) > > > at org.gjt.mm.mysql.MysqlIO.sqlQueryDirect(Unknown Source) > > > at org.gjt.mm.mysql.MysqlIO.sqlQuery(Unknown Source) > > > at org.gjt.mm.mysql.Connection.execSQL(Unknown Source) > > > > > > or > > > NullPointerException. > > > > > > However I created new connection pool (through JNDI lookup) on every > > > HTTP request since my bean where I did all above > > > had a scope="request" (just for testing). > > > > > > And the last GLOBAL question. If I get datasource and connection in the > > > bean, then > > > the only way to have one connection pool for all users who sends HTTP > > > request to my JSP (which using my bean) > > > is to have the scope "application" for the bean. Am I right? > > > > > > Sincerely, > > > -- > > > Lev Assinovsky Peterlink Web > > > Programmer St. Petersburg, Russia > > > Tel/Fax: +7 812 3275343 197022 ul.Chapigina 7? > > > E-mail: [EMAIL PROTECTED] > > > > > > -- > > > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > > > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > > > > > ------------------------------------------------------------------------ > > > Name: winmail.dat > > > winmail.dat Type: application/ms-tnef > > > Encoding: base64 > > > > > > ------------------------------------------------------------------------ > > > -- > > > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > > > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > > > -- > > Lev Assinovsky Peterlink Web > > Programmer St. Petersburg, Russia > > Tel/Fax: +7 812 3275343 197022 ul.Chapigina 7? > > E-mail: [EMAIL PROTECTED] > > > > -- > > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > > > ------------------------------------------------------------------------ > > Name: winmail.dat > > winmail.dat Type: application/ms-tnef > > Encoding: base64 > > > > ------------------------------------------------------------------------ > > -- > > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > -- > Lev Assinovsky Peterlink Web > Programmer St. Petersburg, Russia > Tel/Fax: +7 812 3275343 197022 ul.Chapigina 7? > E-mail: [EMAIL PROTECTED] > > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > ------------------------------------------------------------------------ > Name: winmail.dat > winmail.dat Type: application/ms-tnef > Encoding: base64 > > ------------------------------------------------------------------------ > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> -- Lev Assinovsky Peterlink Web Programmer St. Petersburg, Russia Tel/Fax: +7 812 3275343 197022 ul.Chapigina 7Á E-mail: [EMAIL PROTECTED] -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
