Bill Davidson wrote: > Is it possible to set up a callback like situation so that a trigger in an > Oracle 10g database can call a method in a currently running webapp > that's running in Tomcat 6? > > My situation is that I want to cache some infrequently changed database > data in memory but when that data does change in the database, I want > the web applications, running on multiple servers, to immediately pick > up the change. > > Right now, one idea I have for this is to have the database trigger > create a file in a file system that's shared by the database server and > the application servers and have the web apps check for the existence > of this file to know whether to update the cache. It feels ugly and > means hitting a networked file system a lot but it seems like it should > work and it seems like it should not be as bad as hitting the database > constantly for something that doesn't change very often. > > I'd rather have the database send a message somehow to the web app that > it needs to update its cache of the data. Any suggestions?
1. JMS? 2. Call an reload servlet from the database? 3. Drop the immediate update requirement and poll a data changed flag in the db every x seconds? Personally, I'd go with 3. For a simple flag this could be every few seconds with very little load on the db or Tomcat and would take all of a few minutes to code. Mark --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
