Hi Morten, The proposed solutions are not using the same "pattern" that you use, and it might have serious drawbacks. I personnally stopped Transactional Services (that's the name of the method interceptor based solution that other posters have mentionned) in favor of Open Session In View a long, long time ago, and I don't see any compelling reason to get back to it...
The key issue with Transactional Services is that the hibernate session is usually used once, for a method call, and not for the entire lifecycle of the http request. Objects passed to / returned from DAOs/Services are disconnected from the hb session. This sucks a lot as soon as you e.g. navigate lazy-loaded associations in your JSPs, which I do in almost every single JSP I write ! Using Transactional Services looks compelling, but it clearly enforces a much more complicated design IMHO. You'll often end up with DTOs and the like, which IMHO are just writing code twice... You can't simply use your objects as they persisted magically. In that respect, OSIV provides a much more simple and effective programming model. The only issue with OSIV is that transactions / hibernate sessions are said to be "long lasting" : their lifecycle being the one of the http request. In school, they told you that a db transaction should always being, do only what it's supposed to do, and commit/rollback... In my experience, OSIV has always worked. And btw I don't agree with the DOS argument. Yes, the OSIV solution might not scale as good as the DTO one, and it's certainly easier to DOS an app that doesn't scale. But DOS isn't related to transaction management or anything, it's just about flooding the server. You can do this by many means, even when no db is involved at all... Anyway, in short, if I were you, I'd try to track down where my problem is (starting the app with a profiler might help), and fix it, especially if your app used to work with the same load on a different OS. Switching from OSIV to DTOs will be much more pain IMO. My 0.02 Rémi 2009/6/2 Morten Matras <morten.mat...@gmail.com>: > Let's start with the questions for you: > > - How do I modify the filter below / use another (downloadable) filter to > get a Hibernate Filter in my application that takes care of transaction > management and commit / rollback for me that works on a windows server and > with an application that uses RedirectResolution? > - I consider switching to Stripernate (or whatever it's called now a days). > Would that be a good idea? > > > In our application http://www.redantenna.com I've added a > HibernateRequestFilter inspired by: https://www.hibernate.org/43.html > > The architecture is something like: (MySQL - Hibernate - Tomcat - JSP) > > In this filter I open a new session on every request and either commit it or > roll it back when the request is finished and the .jsp created and returned. > > This has been working fine for years when deployed on linux machines, but > this application is deployed on a windows machine causing this error: > > java.net.SocketException: No buffer space available (maximum connections > reached?): JVM_Bind > at java.net.PlainSocketImpl.socketBind(Native Method) > at java.net.PlainSocketImpl.bind(Unknown Source) > at java.net.Socket.bind(Unknown Source) > at java.net.Socket.<init>(Unknown Source) > at java.net.Socket.<init>(Unknown Source) > > The application tries to connect to a mysql database (on another server) and > is using a port to do that. When this error occurs nothing but a complete > reboot of the server helps. > > I took a look at the source code of the hibernate filter and found that the > session is never closed (unless that happens behind the scenes in commit and > rollback of the transaction). I tried adding a session.close() to the filter > but that caused errors when using RedirectResolution(...) in the > application. > > ---- > > Source code of the doFilter method in the HibernateRequestFilter: > > public void doFilter(ServletRequest request, > ServletResponse response, > FilterChain chain) > throws IOException, ServletException { > > try { > sf.getCurrentSession().beginTransaction(); > if (! sf.getCurrentSession().isConnected() ){ > > sf.getCurrentSession().reconnect(sf.getCurrentSession().connection()); > } > chain.doFilter(request, response); > } catch (StaleObjectStateException staleEx) { > throw staleEx; > } catch (Throwable ex) { > try { > if (sf.getCurrentSession().getTransaction().isActive()) { > log.debug("Trying to rollback database transaction after > exception"); > sf.getCurrentSession().getTransaction().rollback(); > } > } catch (Throwable rbEx) { > log.error("Could not rollback transaction after exception!", > rbEx); > } > > // Let others handle it... maybe another interceptor for > exceptions? > throw new ServletException(ex); > } > finally{ > Session session = sf.getCurrentSession(); > Transaction transaction = session.getTransaction(); > //doCommit is an internal parameter telling the filter whether it should > commit or rollback. > Boolean doCommit = (Boolean) request.getAttribute("commit"); > if (doCommit != null && doCommit.booleanValue()){ > transaction.commit(); > } > if (transaction.isActive()){ > transaction.rollback(); > } > session.close(); > } > } > > --- > > With the last line: session.close(); the application is not able to handle > RedirectResolution correctly. It causes an error saying that the session is > closed. Without that the application get's the "maximum connections > reached?" error causing the server to stop working. > > > > > -- > Morten Matras > Consultant > Blob Communication ApS > Svendsagervej 42 > DK-5240 Odense NØ > P: (+45) 76 6-5-4-3-2-1 > W: www.blobcom.com > E: morten.mat...@gmail.com > > ------------------------------------------------------------------------------ > OpenSolaris 2009.06 is a cutting edge operating system for enterprises > looking to deploy the next generation of Solaris that includes the latest > innovations from Sun and the OpenSource community. Download a copy and > enjoy capabilities such as Networking, Storage and Virtualization. > Go to: http://p.sf.net/sfu/opensolaris-get > _______________________________________________ > Stripes-users mailing list > Stripes-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/stripes-users > > ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Stripes-users mailing list Stripes-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/stripes-users
