Hallo!

I'm writing a web application for tomcat using hibernate. I will try to configure hibernate according the step-by-step guide on http://www.ehow.com/how_7999843_stepbystep-hibernate-tomcat-mysql-tutorial.html.
In step 9 the author disables the 2nd level cache. Can one explain, if and why this is really necessary?
In the worst case I would prefer to use a own sessionfactory instance for each user session. I read the 2nd level cache is sessfactory-based. I think disabling the 2nd level cache completely would cause performance disadvantages. Can someone explain the background of this step?

Thanks!

Hi FischeFr,

the author there just states


You will have potential synchronization issues, when there co-exist several sessfactories instances working with the same database.
I you just have one Servlet in Tomcat acceding Hibernate (and no other Hibernate-App), then this should not be the case as there will be only one single sessionfactory instance, so you could keep the second level cache enabled.
I guess the author worked with more servlets, so he simply disabled the second level cache.
(there are also ways to synchronize 2nd level caches).
And yes, disabling the 2nd level cache can cause performance disadvantages.