>>>how would you solve conflicts? For my purposes, I would let the database manage conflicts. Each application scope object would be tied to the database, a change made on a specific application server would first update the database. For example, the information from a table containing label/value pairs for product categories would be stored in application scope on each server at system startup. If a change were made to the product categories, the change would first made to the database and then a change notification would be broadcast to all servers in the cluster, each server would then reload the information from the database.
In other cases, where application scoped objects are not backed by a database, the task of handling conflicts becomes more difficult. I think you would almost need to create some sort of locking mechanism that does not allow changes to be made during an update. Mike --- "Filip Hanik (lists)" <[EMAIL PROTECTED]> wrote: > not implemented right now, how would you solve conflicts? > > > > Filip > > -----Original Message----- > From: Mike Duffy [mailto:[EMAIL PROTECTED] > Sent: Friday, April 09, 2004 5:48 PM > To: Tomcat Users List > Subject: Clustering Application Scope Objects > > > I've read documentation for The Tomcat 5 Servlet/JSP Container: > Clustering/Session Replication HOW-TO > http://jakarta.apache.org/tomcat/tomcat-5.0-doc/cluster-howto.html > > I understand clustering for individual user sessions. Are there any > correlated methods for > clustering application scope objects? > > The J2EE API for the Interface ServletContext states, "In the case of a web > application marked > "distributed" in its deployment descriptor, there will be one context > instance for each virtual > machine. In this situation, the context cannot be used as a location to > share global information > (because the information won't be truly global). Use an external resource > like a database > instead." > > Rather than use a database, what I would like to be able to do is make a > call to > > servlet.getServletContext().setAttribute(key, object); > > and have the object stored in the application scope of all servers in the > cluster. > > I know that EJBs were designed to serve this purpose; however, I would like > to bypass the overhead > and complexities of EJBs. > > If there isn't a switch that can be flipped in Tomcat, there might be a way > to create a > lightweight JMS administration class to serve this purpose. Has anyone > tried this? > > If the answer to this question is RTFM, please send a link; I've looked > through the documentation > and I can't seem to find a clear reference. > > Thanks for your time and consideration. > > Mike > > > > > __________________________________ > Do you Yahoo!? > Yahoo! Small Business $15K Web Design Giveaway > http://promotions.yahoo.com/design_giveaway/ > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.654 / Virus Database: 419 - Release Date: 4/6/2004 > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.654 / Virus Database: 419 - Release Date: 4/6/2004 > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > __________________________________ Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway http://promotions.yahoo.com/design_giveaway/ --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
