A Shareplex process fails with error: "OCISessionBegin failed with ORA-12705" (4297651)

See the following types of errors associated with one of the Shareplex process like sp_ocap, sp_ordr and sp-opst in the event log:

Error: 12035 - OCISessionBegin failed with ORA-12705. [sp_ocap(osp)/10957]

or

Error: 12035 - OCISessionBegin failed with ORA-12705. [sp_ordr(osp)/29093]

Three possible causes:

1. Either an attempt was made to issue an ALTER SESSION statement with an invalid NLS parameter or value.

2. The NLS_LANG environment variable contains an invalid language, territory, or character set.

3. Oracle itself is unstable because of a library mismatch.

For Causes 1 and 2:

When the character set of the database is set to a different value on source and target, the error can be resolved by setting the parameters SP_ORD_NLS_LANG and SP_OPO_NLS_LANG prior to replicating a character set other than US7ASCII.This will overridethe environment variable NLS_LANG at OS level.

For example, if the character set is American_America.WE8ISO8859P1 and your Unix environment has something like this:
NLS_LANG=American_America.WE8ISO8859P1;export NLS_LANG

Then shutdown Shareplex on source and target, unset the above environment variable and then set the Shareplex parameters as follows:

Source:
sp_ctrl>set param SP_ORD_NLS_LANG SID,American_America.WE8ISO8859P1 (where SID is the Oracle SID)

Target:
sp_ctrl>set param SP_OPO_NLS_LANG SID,American_America.WE8ISO8859P1 (where SID is the Oracle SID)

Then startup Shareplex on source and target.

IFthe character set of the database is set to same value, check the etc/oratab file to see if the ORACLE_HOME is set correctly.

Explanation of Oracle error ORA-12705:

12705, 00000, invalid or unknown NLS parameter value specified
// *Cause: The NLS parameter value specified in an alter session statement
// is not valid or not implemented.

For cause 3:
Check the environment and ensure that the correct libraries are in the environment variables LD_LIBRARY_PATH andLIBPATH. Alsocheck thesymbolic links to libraries in /var/adm/.splex/V-<version>/lib<Oracle version>/

The Oracle librarythat SharePlexis linked to should bethe 32 bit library for the version of Oracle that SharePlex isusing. In the situation where more than onepatch levelof Oracle is installed(i.e. 9.2.0.4/9.2.0.7) then the lower version of the library should be used for all installations of SharePlex.