Install and configure OCI

When you use a DBLink in an Oracle tenant of OceanBase Database to read data from or write data to a remote Oracle database, you must install and configure the Oracle Call Interface (OCI) library.

Procedure

When you use a DBLink to access a remote Oracle database, if the local OceanBase database is of V4.2.1 or later, you must install and configure OCI 12.2 on all OBServer nodes in the cluster by referring to this topic.

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 in 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: libclntshcore.so.12.1, libclntsh.so.12.1, libipc1.so, libmql1.so, libnnz12.so, libocci.so.12.1, libociei.so, libocijdbc12.so, libons.so, and liboramysql12.so.

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

      Notice

      After you copy the .so files from the OCI installation directory to the OceanBase Database installation directory, you need to copy the libclntsh.so.12.1 file in the OceanBase Database installation directory and rename the new file as libclntsh.so, or you can create a soft link that points to the libclntsh.so.12.1 file in the installation directory and name the soft link as libclntsh.so.

      cp libclntshcore.so.12.1 $DIR/lib
      

      cp libclntsh.so.12.1 $DIR/lib
      

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

      cp libipc1.so $DIR/lib
      

      cp libmql1.so $DIR/lib
      

      cp libnnz12.so $DIR/lib
      

      cp libocci.so.12.1 $DIR/lib
      

      cp libociei.so $DIR/lib
      

      cp libocijdbc12.so $DIR/lib
      

      cp libons.so $DIR/lib
      

      cp liboramysql12.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.

6. After you configure the OCI library and the LD_LIBRARY_PATH environment variable, if the OBServer node fails to correctly load all the .so files of OCI, you need to restart the OBServer node. For more information, see Restart a node.

   If it is inconvenient to restart the OBServer node, you can run the mv command to move all the 10 .so files of the OCI library in the $DIR/lib/ directory to the /lib64 directory, and retain only the libclntsh.so file in the $DIR/lib/ directory. Then, the OBServer node can load the OCI library without a restart.

   cd /home/admin/oceanbase/lib
   

   mv libclntshcore.so.12.1 /lib64
   

   mv libclntsh.so.12.1 /lib64
   

   mv libipc1.so /lib64
   

   mv libmql1.so /lib64
   

   mv libnnz12.so /lib64
   

   mv libocci.so.12.1 /lib64
   

   mv libociei.so /lib64
   

   mv libocijdbc12.so /lib64
   

   mv libons.so /lib64
   

   mv liboramysql12.so /lib64
   

Considerations

After you configure the OCI library on all OBServer nodes in the cluster, take note of the following considerations:

• 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
  

• On the x86 platform, OBServer nodes of V4.2.1 and later versions can only run OCI library files in the oracle-instantclient12.2-basic-12.2.0.1.0-1.x86_64.rpm package. If you use OCI library files of an earlier or later version or of multiple versions, processes may crash on the OBServer node.

  On the x86 platform, OBServer nodes of a version earlier than V4.2.1 can only run library files of OCI 11.2. For more information, see Install and configure OCI 11.2.

• On the ARM platform, OBServer nodes can only run OCI library files in the oracle-instantclient19.10-basic-19.10.0.0.0-1.aarch64.rpm package. To download the oracle-instantclient19.10-basic-19.10.0.0.0-1.aarch64.rpm package, click oracle-instantclient19.10-basic-19.10.0.0.0-1.aarch64.rpm.

  The process for configuring the OCI library on the ARM platform is similar to that of the x86 platform. You can configure all the .so files in the oracle-instantclient19.10-basic-19.10.0.0.0-1.aarch64.rpm package by referring to this topic.