Install and configure OCI

When an Oracle tenant in OceanBase Database needs to read and write data from a remote Oracle database through DBLink, it is necessary to install and configure the Oracle Call Interface (OCI) library.

Procedure

For OceanBase Database V4.2.1 and later, when you use the DBLink feature to access a remote Oracle database, refer to this documentation and configure OCI 12.2 on all OBServer nodes in the cluster.

The following example describes how to install and configure an OCI library on a single OBServer node.

1. Click here to go to the official website of OCI and download the OCI library of the corresponding version.

2. Log on to the OBServer node as the admin user, copy the downloaded RPM package to the OBServer node, and run the following command to install the OCI library:

   sudo rpm -ivh oracle-instantclient12.2-basic-12.2.0.1.0-1.x86_64.rpm
   

3. After the OCI library is installed, run the following command to obtain the OCI installation directory:

   rpm -ql oracle-instantclient12.2-basic-12.2.0.1.0-1.x86_64
   

   The result is as follows:

   /usr/lib/oracle/12.2/client64/bin/adrci
   /usr/lib/oracle/12.2/client64/bin/genezi
   /usr/lib/oracle/12.2/client64/lib/libclntsh.so.12.1
   /usr/lib/oracle/12.2/client64/lib/libclntshcore.so.12.1
   /usr/lib/oracle/12.2/client64/lib/libipc1.so
   /usr/lib/oracle/12.2/client64/lib/libmql1.so
   /usr/lib/oracle/12.2/client64/lib/libnnz12.so
   /usr/lib/oracle/12.2/client64/lib/libocci.so.12.1
   /usr/lib/oracle/12.2/client64/lib/libociei.so
   /usr/lib/oracle/12.2/client64/lib/libocijdbc12.so
   /usr/lib/oracle/12.2/client64/lib/libons.so
   /usr/lib/oracle/12.2/client64/lib/liboramysql12.so
   /usr/lib/oracle/12.2/client64/lib/ojdbc8.jar
   /usr/lib/oracle/12.2/client64/lib/xstreams.jar
   

4. Configure the OCI library.

   1. Check whether a lib directory exists in the OceanBase Database installation directory. If not, create one and specify privileges required to access the lib directory. If yes, skip this step.

      In this example, the OceanBase Database installation directory is /home/admin/oceanbase.

      sudo mkdir /home/admin/oceanbase/lib
      

      sudo chown admin:admin -R /home/admin/oceanbase/lib
      

   2. Go to the OCI installation directory.

      cd /usr/lib/oracle/12.2/client64/lib/
      

   3. Copy the following files from the OCI installation directory to the OceanBase Database installation directory: libclntsh.so.12.1, libclntshcore.so.12.1, libipc1.so, libmql1.so, libnnz12.so, libociei.so, and libons.so.

      You need to replace $DIR with the OceanBase Database installation directory, which is /home/admin/oceanbase in this example.

      Notice

      You need to rename the libclntsh.so.12.1 file to libclntsh.so.

      cp libclntsh.so.12.1 $DIR/lib/libclntsh.so
      

      cp libclntshcore.so.12.1 $DIR/lib
      

      cp libipc1.so $DIR/lib
      

      cp libmql1.so $DIR/lib
      

      cp libnnz12.so $DIR/lib
      

      cp libociei.so $DIR/lib
      

      cp libons.so $DIR/lib
      

5. Specify the LD_LIBRARY_PATH variable.

   To load the libclntsh.so file, OceanBase Database searches for dependent library files in the directory specified by the LD_LIBRARY_PATH variable. Therefore, you need to set the LD_LIBRARY_PATH variable to the directory of the OCI library.

   In this example, the OCI library is located in home/admin/oceanbase/lib. Here is a sample command:

   export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/home/admin/oceanbase/lib:"
   

   Notice

   You must append a colon (:) to /home/admin/oceanbase/lib when you configure environment variables.

Considerations

After you configure the OCI library on all OBServer nodes in the cluster, note that:

• OceanBase Database requires dependent libraries to load the OCI library. After you configure the OCI library, you can run the ldd libclntsh.so command in the directory of the OCI library, which is home/admin/oceanbase/lib in this example, to query other Linux libraries on which the OCI library depends. If the required dependent libraries do not exist, contact OceanBase Technical Support for assistance.

  ldd libclntsh.so
  

• In general, you do not need to restart the OBServer node after the OCI library is configured. However, if an error message is returned and indicates that OCI is not found, you need to restart the OBServer node.