I'm using a singleton bean (@Singleton @Startup) in my application to
implement a pool of network connections to different servers. However, after
redeploying my application, this singleton bean is not thrown away. So it
happens, that after three redeployments there are four such beans lingering
around. All these beans are active, which makes things really bad in my case
since every server that I contact only allows a fixed number of logins with
the same username/password. One server allows e.g. five parallel connections.
Having n of those beans started after a redeployment, they would try to
establish 5*n such connections, 5*(n-1) of which will fail, so I have n-1
"zombies" lingering around, making my application useless.
My setup: GlassFish 3.1.1 (build12), JDK 1.7.0
This behaviour can be seen with a very simple example, which I have attached.
If you deploy it to GF, remember to copy log4j-1.2.16.jar and
commons-logging-1.1.1.jar to <domainHome>/lib/ext.
I have also attached my pom.xml (remove .txt ending, couldn't upload .xml),
if you want to compile the sources using maven.
I believe that this bug is somehow related
to
http://java.net/jira/browse/GLASSFISH-12368 [1], but this is an entry
which is 1.5 years old, I believe that there are solutions out there
already...
The reason why I chose to implement my code with a singleton bean is the
possibility to define a @PreDestroy method to logout cleanly from the
connected servers (otherwise they wouldn't let me in next time I try to
connect. Yes, they are picky...). Due to the described restrictions it is not
possible for me to use any other kind of bean. It is quite important in my
scenario that there's only one connection pool bean.
Are there any other, possibly more elegant and/or more efficient methods to
implement such pools of remote connections? (some are TCP, some HTTPS, some
HTTP connections).
Thanks for any help in advance! I greatly appreciate your input!
Cheers,
Manfred
[1]
http://java.net/jira/browse/GLASSFISH-12368
--
[Message sent by forum member 'docmani']
View Post: http://forums.java.net/node/883053