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  1. Commons DBCP
  2. DBCP-163

[dbcp] Use setQueryTimeout in combination with validationQuery to recover from network problems



    • Improvement
    • Status: Closed
    • Minor
    • Resolution: Fixed
    • 1.1
    • 1.3
    • None
    • Operating System: Linux
      Platform: Other

    • 30391


      When the network connection between tomcat 4.1.29 and database (experienced with
      sybase ASE 12.5) is lost, the 'Connection' hangs indefinitely.

      It hangs in the line of code "con = DatasourceObject.getConnection();"

      None of the other options in the connection pooling stuff - add info: used
      SharedPoolDatasourceFactory in dbcp - like maxWait / validationQuery
      /removeAbandoned/ removeAbandonedTimeout etc doesnt timeout the connection.

      Analysis: When the network connection to the database is fine (normal scenario)-
      the dbcp gets a connection from the datasource (connection pool)- sets three
      params - autocommit, readonly and isolation level for the connection object and
      returns this improved connection object to the calling class.

      Now say the network connection is lost, and the unaware application requests for
      a connection from the pool, gets the connection object and then tries to set the
      first of three params (autocommit- mentioned above) where it hangs.

      None of the timeout params work in this scenario. Setting a validationQuery
      tries its validation only after getting the connection object which never happens.

      Soln(possibility): after getting the raw connection object - run a validation
      query (or any call to database)with a stmt.setQueryTimeout() set to say 3-5 secs

      • or say configurable by user - and then catch the exception (noroutetohost
        exception) to throw it back.




            Unassigned Unassigned
            dilish.k@sonata-software.com cryptic
            5 Vote for this issue
            3 Start watching this issue