ORA-12547: TNS:lost contact

ORA-12547: TNS:lost contact

ORA-12547: TNS:lost contact

Brbackup, brarchive, brrestore or brconnect may terminate with errors similar to the following:

BR301E SQL error -12547 at location BrDbConnect-1

BR301E SQL error -12547 at location dbf_info_get-1

Sapdba returns the following error, for example:

  SAPDBA: ORACLE error -12547 occurred while checking instance status!

The R/3 work processes or R3trans return the following error at Connect:

  C  *** ERROR => CONNECT failed with sql error '12547'

ORA-12547: TNS:lost contact

As part of the Net8 Connect, a program such as the R/3 kernel, R3trans, svrmgrl, sqlplus or ODMA establishes a connection to the Oracle database. If the connection terminates due to problems at the server end, it can result in ORA-12547.

Additional information for the error is often available in sqlnet.log. In many cases, other messages that are not reported by all tools precede ORA-12547. If ORA-12547 occurs when the ODMA accesses the old Oracle-Home during a database upgrade, for example, it may make sense to temporarily restart ORACLE_HOME on the old Oracle-Home for test purposes and then to execute sqlplus or svrmgrl.

Even if sapdba or the BR tools terminate with an ORA-12547 when calling sqlplus or svrmgrl recursively, you should, for test purposes, call sqlplus or svrmgrl manually with the operating system user that was used.

Hopefully, a more informative error message will be displayed in addition to ORA-12547, for example:

  ld.so.1: oracleC11: fatal: relocation error: file

           /oracle/C11/817_64/libx8.so: symbol ksunsga_:

           referenced symbol not found

If you find accompanying error messages of this type, start a note search with the corresponding search terms since we are often aware of the problem and a solution may already be available. If you do not find any significant error messages or a suitable note, check the following possible causes for ORA-12547:

1. UNIX: Incorrectly linked Oracle tools

2. UNIX: Problems with XPG4 compliance and s-bit

3. Too many simultaneous inquiries on the listener

4. HP-UX, Oracle 8.1: Missing OS patch

5. Use of CRYPTO parameters in sqlnet.ora

6. AIX: I/O Async is deactivated

7. Resource problems

8. The CONNECT_TIMEOUT_LISTENER parameter in listener.ora is too low

9. Activated Oracle trace

10. UNIX: Incorrect authorizations for the Oracle executable

11. SOLARIS: LD_LIBRARY_PATH set when you call ODMA

12. AIX: Problem with post/wait kernel enhancement

13. UNIX: Problems with the libobk library

14. SOLARIS: Incorrect search sequence in the path variable

15. UNIX: Conflicts between 32-bit and 64-bit files

16. Oracle Version 10.2.0.2 or higher, AIX: /proc not mounted

17. Oracle 10g or higher, WINDOWS: Timeout during logon

Solution for ORA-12547: TNS:lost contact

1. Relink the Oracle software as ora<sid> with

  cd $ORACLE_HOME/rdbms/lib

  make -f ins_rdbms.mk install

              or

  relink all

2. For more information, see Note 88884.

3. If individual work processes terminate with ORA-12547 when you start an R/3 instance, see Note 131561.

4. For more information, see Note 399610.

5. You can set security parameters that begin with SQLNET.CRYPTO_ in sqlnet.ora as part of the Advanced Security Option. Oracle releases lower than 8.1.7 cannot process these parameters correctly and result in ORA-12547. In this case, delete these types of parameters from sqlnet.ora.

6. If I/O is deactivated on AIX Async, the Net8 Connect fails with ORA-12547. In this case, activate I/O Async by using smitty.

7. Insufficient resources such as available memory on the database server can cause ORA-12547. For more information, see Note 384839.

8. In individual cases, it may make sense to increase the CONNECT_TIMEOUT_LISTENER parameter in listener.ora (for example, by 5 seconds, so from 10 to 15). Although a value of 10 seconds should usually be sufficient to establish a connection.

9. Delete the log files written by the Oracle trace in accordance with Note 92537.

10. Check to see whether the executable in $ORACLE_HOME/bin has the "rwsr-s--x" authorizations and the ora<sid> owner and correct this if required.

11. If you call ODMA on SOLARIS as part of a database upgrade and if LD_LIBRARY_PATH is set explicitly (on the lib directory of the target release), calling the old Oracle software through ODMA may fail with ORA-12547. If you use the old ORACLE_HOME to list sqlplus or svrmgrl, you get the following error:

  ld.so.1: oracle<sid>: fatal: relocation error:

          file /oracle/<sid>/817_64/libx8.so: symbol ksunsga_:

          referenced symbol not found

  ORA-12547: TNS:lost contact

              In this case, permanently delete LD_LIBRARY_PATH from the environment. This does not have any negative effects since the libraries are automatically found in the correct directories as of Oracle 8.1.

12. If problems occur with the post/wait extension on AIX, the following type of errors will be displayed:

  exec(): 0509-036 Cannot load program oracleC11 because of the

  following errors:

          0509-130 Symbol resolution failed for oracle because:

          0509-136  Symbol pw_post (number 2524) is not exported

                    from dependent module /unix.

          0509-136  Symbol pw_wait (number 2525) is not exported

                    from dependent module /unix.

          0509-136  Symbol pw_config (number 2526) is not exported

                    from dependent module /unix.

          0509-192 Examine .loader section symbols with the

                  'dump -Tv' command.

  ORA-12547: TNS:lost contact

              In this case, also refer to Note 49905.

13. If the libobk library was created incorrectly, the following type of errors may occur:

  /oracle/C11/817_64/bin/oracle: /sbin/loader:

    Fatal Error: Cannot map library libobk.so

  /usr/lib/pa20_64/dld.sl: Unable to find library

    '/oracle/C11/lib64/libobk.sl

  exec(): 0509-036 Cannot load program oracleC11 because of the

          following errors:

  0509-150   Dependent module /oracle/C11/817_64/lib/libobk.a(shr.o)

            could not be loaded.

  0509-152   Member shr.o is not found in archive

  ORA-12547: TNS:lost contact

              Check to see whether libobk exists and, if it is a link, that it points to a valid object. Note 142635 contains more information about this. The libobk link may point to this if a libsbtsh8.* file exists in the Oracle library directory. If you are using a third-party Backint tool, contact the relevant supplier, since libobk often has to point to a backint-specific library.

14. If an error such as

  ld.so.1: ./svrmgrl: fatal: libucb.so.1: open failed:

          No such file or directory

  ORA-12547: TNS:lost contact

              occurs, the PATH has probably been set incorrectly. For more information, see Note 44361.

15. If an error such as

  ld.so.1: oracle<sid>: fatal: <library> wrong ELF class: ELFCLASS64

  ORA-12547: TNS:lost contact

              concerning "wrong ELF class" occurs, check whether the <library> mistakenly has a different bit size than the tool that was called. You can determine this using

  file <library>

  file <tool>

              . All the files involved must uniformly be either 32-bit or 64-bit.

16. For more information, see Note 954896.

17. For more information, see Note 1055400.