Conference orarep::nomahs::dectrace_v20

463.0. "Trace enabled in many Oracle7 7.3.2, 7.3.3 releases" by OOTOOL::CRAIG () Wed Apr 30 1997 12:14

          <<< NOMAHS::DISK$NOMAHS1:[NOTES$LIBRARY]RDBEXPERT.NOTE;1 >>>
                         -< DEC RdbExpert for OpenVMS >-
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Note 742.0     Trace enabled in many Oracle7 7.3.2, 7.3.3 releases       1 reply
NOMAHS::SECRIST "Rdb WWS; [email protected]"   135 lines  29-APR-1997 10:57
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Document ID:         12195827.61
Title:               Oracle Trace is Enabled by default
Creation Date:       25-April-1997
Last Revision Date:  25-April-1997
Revision Number:     0
Product:             RDBMS
Product Version:     7.3.X
Platform:            GENERIC
Information Type:    ADVISORY
Impact:              HIGH
Abstract:            This article gives an indication of the sort of problems
                     that may be seen if Oracle Trace is enabled.
Keywords:            ORACLE;TRACE;ENABLED;EPC_DISABLED
________________________________________________________________________________
Oracle Trace is Enabled by default
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  Versions Affected
  ~~~~~~~~~~~~~~~~~
    Oracle Trace was introduced in Oracle7 release: 7.3.2.1
    It is enabled by default in many 7.3.2 and 7.3.3 releases.

  Platforms Affected
  ~~~~~~~~~~~~~~~~~~
    Oracle Trace is enabled by default on most Unix platforms.
    Oracle Trace is NOT included with Windows NT 7.3.2 releases.


  Description
  ~~~~~~~~~~~
    Oracle Trace is a new, common tracing mechanism which is automatically
    enabled in Oracle 7.3.2 on most platforms. Products instrumented with
    Oracle Trace include:
        SQL*Net v2.3
        Oracle Server 7.3
        Oracle Forms 5.0
    Unless specific actions are taken Oracle Trace may be enabled when it is
    not required.


  Likelihood of Occurrence
  ~~~~~~~~~~~~~~~~~~~~~~~~
    On Unix platforms it is quite likely there is some impact from Oracle
    Trace being enabled, even if this is only a small performance degradation.

    Please Note: Oracle trace works well if correctly configured and used
                 in a targeted manner. The problems described here can
                 occur when Oracle Trace is not configured and is widely
                 enabled .

  Possible Symptoms
  ~~~~~~~~~~~~~~~~~
    Widespread use of Oracle Trace can have a number of apparently mysterious
    side effects including:

        - Very slow database connect times

        - Poor Oracle response times

        - High disk space usage by the file 'process.dat'

        - Oracle errors attaching to the SGA, such as ORA 7307 or ORA 7337

        - Protocol errors (such as TNS 12164) errors from SQL*Net

        - Sessions aborting or hanging when connecting to the instance

        - Bus errors and/or core dumps from SQLPLUS or SVRMGRL

        - Trace files being written to the default USER_DUMP_DEST rather
          than the actual setting of USER_DUMP_DEST

        - Zero length trace files

  Workaround / Patches
  ~~~~~~~~~~~~~~~~~~~~
    There are no patches available.

    The workaround is to set the parameter EPC_DISABLED to TRUE in the
    users environment.

    Workaround on Unix:
    ~~~~~~~~~~~~~~~~~~~
      1. Shut down all 7.3 databases.

      2. Reinitialise the Oracle Trace output files:

                cd $ORACLE_HOME/otrace/admin
                rm -f process.dat regid.dat
                otrccref

      3. Set the environment variable EPC_DISABLED to TRUE for all users.
         If you have a common environment script where ORACLE_HOME is set
         this is probably the best place to set this.
         Eg: In a Bourne script:
                EPC_DISABLED=TRUE; export EPC_DISABLED

             In the C-Shell:
                setenv EPC_DISABLED TRUE

      4. Make sure any SQL*Net connections have EPC_DISABLED in the
         environment. To ensure this you can modify the 'SID_LIST_listener'
         clause in the 'listener.ora' file and add:

                (ENVS='EPC_DISABLED=TRUE')

         to the SID_DESC for each 7.3 database. Add the entry AFTER the
         (ORACLE_HOME=...) clause.

         Eg:
            SID_LIST_LISTENER=
             (SID_LIST=
              (SID_DESC=
                (SID_NAME=DB1)
                (ORACLE_HOME=/oracle/OFA_base/app/oracle/product/7.3.2)
                (ENVS='EPC_DISABLED=TRUE')
              )
              (SID_DESC=
                (SID_NAME=DB2)
                (ORACLE_HOME=/oracle/OFA_base/app/oracle/product/7.3.2)
                (ENVS='EPC_DISABLED=TRUE')
              )
            )

        5. Restart and databases and SQL*Net listeners.

  References
  ~~~~~~~~~~
    Connection/query time is slow                       <PR:1020763.6>
    Slow connect times                                    <Bug:443047>
    ORA 7307 Unable to attach SGA                         <Bug:374964>
    Server Process hanging                                <Bug:387185>
_______________________________________________________________________________
                                             Oracle WorldWide Customer Support
    

Better yet, if the customer does not want to shut down, they don't have to
if they are not going to use Oracle Trace, 

Just delete $ORACLE_HOME/otrace/admin/*.dat

Simple and more effective than the EPC_DISABLE

George