Hallo,

We are using hibernate with very impressive results. Averything works fine, but we still no have a solution for this problem:

When our mysql server restarts, the application do not allow any further requests by hibernate. It seems that the sessionFactory needs to reconnect. The serverside message is:

Sep 25, 2003 6:40:51 AM net.sf.hibernate.JDBCException <init>
SEVERE: Could not execute query
java.sql.SQLException: No operations allowed after connection closed
at com.mysql.jdbc.Connection.checkClosed(Connection.java:2497)


We use the following code to implenet the session factory with application scope inside an initializer servlet:

public void init(ServletConfig config) throws ServletException {
super.init(config);
...
// build a SessionFactory
sessionFactory = ds.buildSessionFactory();
...
// store session factory in application context
ServletContext app = getServletContext();
app.setAttribute("hibernate.sessionFactory", sessionFactory);
}

Has anyone such problems and any kind of solution? Maybe we have to use a connection pool.

Any help is welcome,

Andreas Bednarz

I was thinking that perhaps you have a method (a thread that sleeps, e.g.) that wakes up every few seconds and does a simple query, which you know will work, and if it fails - catch (net.sf.hibernate.JDBCException) {}

Then in catch statement, recreate the SessionFactory, as per your servlet.

That's just off the top of my head, perhaps someone can give a more direct/proper approach.

-G

Do you mean a kind of background thread which runs parallel to my servlet engine in same application context with low priority?

Andreas

Perhaps that. Or even, have a method that you call, perhaps like this:


Then, just before you want to make any call to the database, simply run checkSessionFactory().

Any help? :)

-G

That should be:


in the first line...
Wish I could edit my post. :P

-G

This is really the job of the connection pool, not the application or Hibernate.

Thank you very much,

I decided to use the background session reconnect running as a thread. The pooling would be also fine, but we can not use it in our application.

Andreas