Make sure your developers properly close resultsets and statements. It could be
that they remain open after exceptions. Make sure you have the closing
statements in the finally section of try/catch/finally.
hth
*********************************************************************
* Boris Niyazov Ph: 212-854-4094 Fax: 212-854-1749 *
* Systems Manager Email: [EMAIL PROTECTED] *
* Columbia Law School URL: http://www.law.columbia.edu *
*********************************************************************
>
>hi all!
>
>problem:
>--------
>
>database access is managed via a java class that is
>instantiated and loaded into each clients session. every
>PL/SQL function and/or SQL statement a client needs is
>called in a method of this class.
>first, a connection is opened, the statement is called,
>all resultsets and statements are closed and finally the
>connection is closed. (or returned back to the
>connection pool if one is used)
>
>the driver we use is the Oracle jdbc ThinDriver (jdbc
>driver type 4). after running the system for several
>days, dead connections (and as we just discovered, tons
>of open cursors) pile up.
>eventually the webserver(tomcat) will crash or just
>hang.
>in the process, access gets slower and slower, there may
>be delays of 3 minutes until the webserver (or, perhaps
>the database, in which case the webserver would be just
>waiting for the db..) gives a response.
>after a restart of the webserver or the database or
>both, the system runns very well again.
>
>we tried several connection pools. with these, there
>were no delays for getting a connection, but the pool
>threw timeoutExceptions (i.e. made it visible that there
>are hanging connections) and after a few hundred
>timeouts the VM crashed with a stack overflow.
>
>the connections seem to get killed/kill themselfes
>randomly no matter which function was called. we log the
>methods and statements that were called for the
>connections that die, but there is just no pattern in
>it. thats why we dont find the root of the problem.. is
>it the driver ? the database ? the tomcat ?
>
>
>
>environment:
>----------------
>
>Web Server:
>Suse Linux 7.2
>Apache Webserver /w Tomcat JSP Engine 3.2 /w SSL
>
>DB Server:
>Suse Linux 7.2
>Oracle 8i 8.1.7 /w multi-threaded server (MTS)
>
>Backup Server:
>Oracle Shadow server
>
>
>
>things done:
>------------
>
>- linux update
>- apache update
>- tomcat update
>- jdbc thin driver update
>(everywhere the newest version)
>- tried several connection pools
>
>
>
>possible changes:
>-----------------
>
>- use OCI drivers instead of thin driver
>- use J-serv with GNU_jsp instead of tomcat
>
>
>
>
>every help is welcome, we're frustrated to no ends.
>thanks very much in advance!!
>
>l.s�gesser
>
- Boris
