java shutdown hook and classpath
Hi and Happy New Year! I have a library that uses JDBC and is being used within a my web app. The library and JDBC driver jars are in the web app's WEB-INF/lib directory. The library installs a Java shutdown hook, which ultimately uses the JDBC driver to do some clean ups in the database. I'm getting a class not found error when trying to load the JDBC driver (in this case derby) in the hook. I suspect this is because the shutdown hook has been called with a class loader that does not have access to WEB-INF/lib. Any thoughts or solutions? Thanks. David Wood Policy Technologies Group IBM TJ Watson Research Center daw...@us.ibm.com 914-784-5123 (office), 914-396-6515 (mobile)
RE: tomcat pauses then crashes after a period of time
Ok, I have found the problem. A firewall between my tomcat server and a
MySQL server was closing the database connection. I was checking if this
was closed in the web service, using the Connection.isClosed() method, but
that does not work as expected and was returning true even though the
connection was closed. The execution continued and an exception was thrown,
where in the catch{} section I was then calling System.exit(), which I
thought would shut down the web service only, but it is actually shutting
down the whole JVM, causing tomcat to stop too.
Thanks for you help,
Dave
-Original Message-
From: Caldarale, Charles R [mailto:[EMAIL PROTECTED]
Sent: Monday, 11 December 2006 2:28 PM
To: Tomcat Users List
Subject: RE: tomcat pauses then crashes after a period of time
From: David Wood [mailto:[EMAIL PROTECTED]
Subject: tomcat pauses then crashes after a period of time
I have set up tomcat to run as a daemon using jsvc, which is
working well, except when tomcat is idle for a period of time
(usually overnight), and I execute a web service client, tomcat
receives the request then simply stops.
No answers, but could you run Tomcat from a shell for a while and see if
anything informative comes out on the console?
- Chuck
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RE: tomcat pauses then crashes after a period of time
Chris,
Thanks very much for the suggestion.
I'm not using connection pooling at this stage. I have deployed my web
service scoped as an Application. It only uses one connection, and the
classes maintain some medium sized data structures which I do not want to
have to re-create each time the service is consumed. I'll investigate the
pooling, as an auto-reconnect feature will be necessary in some form or
another, and if DBCP can do it then that would be great, even if I maintain
only one connection I guess...
cheers
Dave
-Original Message-
From: Christopher Schultz [mailto:[EMAIL PROTECTED]
Sent: Tuesday, 12 December 2006 10:33 AM
To: Tomcat Users List
Subject: Re: tomcat pauses then crashes after a period of time
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
David,
David Wood wrote:
Ok, I have found the problem. A firewall between my tomcat server and a
MySQL server was closing the database connection.
[snip]
The execution continued and an exception was thrown,
where in the catch{} section I was then calling System.exit(), which I
thought would shut down the web service only, but it is actually shutting
down the whole JVM, causing tomcat to stop too.
Heh, well /there's/ yer problem.
Firewalls are known for terminating idle TCP/IP connections after a
certain period of time, which is unfortunate, as many deployments put
the database behind the firewall and the app servers out front.
Are you using any kind of database connection pooling? If so, perhaps
there is an auto-reconnect feature available for that component. For
instance, Jakarta Commons DBCP includes such a feature. Once you are
using DBCP, your code doesn't have to know how to handle unexpected
disconnects like that, since the connection pool handles the automatic
reconnection for you.
Hope that helps,
- -chris
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RE: tomcat pauses then crashes after a period of time
I'll try that but I think it will give me the same error message. I have redirected console output to the Catalina.out file. -Original Message- From: Caldarale, Charles R [mailto:[EMAIL PROTECTED] Sent: Monday, 11 December 2006 2:28 PM To: Tomcat Users List Subject: RE: tomcat pauses then crashes after a period of time From: David Wood [mailto:[EMAIL PROTECTED] Subject: tomcat pauses then crashes after a period of time I have set up tomcat to run as a daemon using jsvc, which is working well, except when tomcat is idle for a period of time (usually overnight), and I execute a web service client, tomcat receives the request then simply stops. No answers, but could you run Tomcat from a shell for a while and see if anything informative comes out on the console? - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
