4 Replies Latest reply on Mar 6, 2003 8:58 AM by davidjencks

    How to track JDBC connection leak?

    srouil
    srouil Feb 8, 2003 2:53 PM

      Hi,

      I am facing a JDBC connection leak problem with my J2EE app running of JBoss 3.0.x and JDK 1.4.1_01. I already looked at the code to chack that all ResultSet, PreparedStatements and Connection are closed in finally blocks.

      Is there any other mean of tracking connection leaks in JBoss 3.0.x like enabling tracing of the connection pool or similar? I looked at the code of LocalTxConnectionManaged and related classes and it does not seem to log a lot.

      Any help about how to solve this will be greatly appreciated.

      Samuel

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        • 1. Re: How to track JDBC connection leak?
          davidjencks
          davidjencks Feb 8, 2003 9:02 PM (in response to srouil)

          You could try deploying your app on jboss 4 where the default behavior is now to violate the jca spec and close any connections you leave open, with a loud warning.

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          • 2. Re: How to track JDBC connection leak?
            srouil
            srouil Feb 10, 2003 12:03 PM (in response to srouil)

            Hi,

            I set-up a JDBC driver (mimer jtrace) that logs all the connects and statements done through JDBC. This allows me to see that the last transaction done with each connections follows the same pattern (same code):

            call to SLSB A (start transaction)
            SLSB A calls some EB's (resulting only in selects)
            SLSB A calls SLSB B that does an insert
            SLSB A calls a Java object that calls some EB's (resulting only in selects)
            SLSB A calls a Java object that calls SLSB B that does an update of same record
            call to SLSB A returns (commit)

            After the commit, the connection is never reused.

            I can say that all ResultSet and (Prepared)Statement are closed properly. I see it also from the JDBC log.

            Should I search for a lock contention in my DB (Oracle 8.1.7), for error in my app or a configuration or other problem in JBoss 3?

            Samuel

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            • 3. Re: How to track JDBC connection leak?
              vpopov19621
              vpopov19621 Mar 5, 2003 9:39 AM (in response to srouil)

              Hi Samuel,

              I have the same problem. Did you figure out how to solve it?

              Thanks,
              Valeri

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              • 4. Re: How to track JDBC connection leak?
                davidjencks
                davidjencks Mar 6, 2003 8:58 AM (in response to srouil)

                Start by trying 3.0.7 (currently from cvs), 3.2RC2 or RC3(RC3 currently from cvs) or 4 (if you want to live dangerously) and see if JBoss thinks you are not closing any connections. So far these problems have always turned out to be from unclosed connections, no matter what other tracing was used.

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