Memory Leak

Vaadin 6 / 7 / 8
1

Hi,

I am concerned about the memory leak in Vaadin application.
I set a debug on in the Vaadin Application and the log states as below;

SEVERE: The web application
[/securitydashboard] created a ThreadLocal with key of type [com.vaadin.util.CurrentInstance$1]
(value [com.vaadin.util.CurrentInstance$1@11305c97]
) and a value of type [java.util.HashMap]
(value [{class com.vaadin.server.VaadinService=com.vaadin.util.CurrentInstance@7e0ec651, class com.vaadin.server.VaadinServlet=com.vaadin.util.CurrentInstance@7bfe307e}]
) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.

I wonder what caused it. For your information, I use Vaadin version 7.0.5

Regards,

Michael Glanvill

2

You should have a look at this forum post:
Forum post

and this ticket:
Ticket

3

I found two more exceptional cases that could leak a little memory this way at application redeploy time and created tickets
#11905
 and
#11906
 (also mentioned in the other thread).

Note that Tomcat (which is printing out these warnings) will eventually clean these up as the message says by not reusing the same threads indefinitely, so in practice this should not be a problem even in environments where you redeploy new versions constantly.