Conference orarep::nomahs::rdbexpert

742.0. "Trace enabled in many Oracle7 7.3.2, 7.3.3 releases" by NOMAHS::SECRIST (Rdb WWS; [email protected]) Tue Apr 29 1997 10:57

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
    

	hi Richard,

	Good information.

	I'll post it in the Trace notesfile too!

	Thanks,
	Sheri

    
    	; I'll post it in the Trace notesfile too! 
    
    Whoops !
    
    8-)
    rcs