[opencms-dev] Reolads and too many connections problem

[Oliver Faulhaber]

severeal messages ago, there has been talked about too many connections and 
about restarting Tomcat (to update classes).

We use the Tomcat ManagerServlet to start, stop and reload OpenCms. After a 
certain amount of reloads, there are too many connections existing in the 
MySql server.

We stepped through the code and encountered following: While stopping the 
OpenCms application, the DB connections are destroyed correctly. Everything 
seems cleared, but the CmsCronScheduler has not been stopped. It normaly 
wakes up every minute + 10 seconds. When OpenCms is stopped, then the 
CmsCronScheduler throws the Exception below and terminates.

WebappClassLoader: Lifecycle error : CL stopped
java.lang.NoClassDefFoundError: com/opencms/core/CmsCronScheduleJobStarter
        at com.opencms.core.CmsCronScheduler.run(CmsCronScheduler.java:90)

The problem is, that before the Scheduler terminates, it will restore the 
connection pool, which will exist until the Tomcat server shuts down. This 
is the reason, why the DB-Server (MySql) hangs up after a certain number of 
OpenCms-reloads.

Hence, explicit destroying the Scheduler helps. We have implemented the 
solution here, but we would be very glad, if the changes would be part in 
the next release. We can't find a bug tracking system like Bugzilla, thus we 
will report the changes here:

Changes in class CmsCronScheduler:

add a new Member variable: private boolean m_destroyed = false;


in method run(), change the loop criteria from for(;;) into

while(!m_destroyed) { // ever

and after the catch block insert:

if( m_destroyed)
   break;

(Before the Scheduler can do its work) Further, add the destroy Method:

public void destroy()
{
   m_destroyed = true;
}


Changes in class OpenCms, method destroy(): insert a new line (we have 
inserted it as the first line):

m_scheduler.destroy();

Thats it. Applying this changes, we can reload OpenCms as often we need.

Regards,
Oliver

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