Instant Client Initilization in Thick Mode and Setting LD_LIBRARY_PATH

[MosGeo]

1. What versions are you using?

instant_client_version: tested on 21 and 23 on Linux 64bit
plaform.python_version: 3.12.11
platform.platform: Linux
oracledb.__version__: 3.4.2

2. Is it an error or a hang or a crash?

Error

3. What error(s) or behavior you are seeing?

When calling init_oracle_client to initialize thick mode with the defined lib_dir variable point to the folder, the following error is obtained.

DatabaseError: DPI-1047: Cannot locate a 64-bit Oracle Client library "libnnz.so: cannot open shared object file: No such file or directory"

The error can be removed by setting the LD_LIBRARY_PATH to point to the instant client before starting the python process (the variable cannot be set using os.environ inside the python process). However, this workaround:

1. Is a differnet behaviour than the Windows version of init_oracle_client where only the lib_dir need to be defined.
2. Is not ideal as another script need to be run before the python process to set the LD_LIBRARY_PATH for the users.

4. Does your application call init_oracle_client()?

I am using thick mode

5. Include a runnable Python script that shows the problem.

import oracledb
oracledb.init_oracle_client(lib_dir="path/to/instant_client")

Final notes

This is probably can be classified as the wrong expected behaviour rather than a bug in the technical term. I understand that there are workarounds to set the LD_LIBRARY_PATH automatically for users and using the installers for the instant client. However, this removes some of the portability of hte the instant client (i.e., zip version).

Anyway, I thought to document it here and see if anybody has a best practice for this issue.

[cjbj]

Thanks for posting. This is a known, intractable 'feature' of a one library in Instant Client on Linux. Sadly it's out of control of python-oracledb and despite many efforts with the owners of that library, there hasn't been a nice solution forthcoming.

See the python-oracledb documentation Enabling python-oracledb Thick Mode on Linux and Related Platforms:

On Linux and related platforms, enable Thick mode by calling init_oracle_client() without passing a lib_dir parameter.

Also see troubleshooting DPI-1047:

On Windows and macOS, pass the lib_dir library directory parameter in your oracledb.init_oracle_client() call. The parameter should be the location of your Oracle Client libraries. Do not pass this parameter on Linux.

[MosGeo]

@cjbj Thanks for the reply.

After further invistigation, it is indeed out of the hands of python-oracledb.

The fix for this should be in the instant client itself. The libclntsh.so should have an rpath of $ORIGIN. This will instruct the library to search in its own directory too and it would find the needed .so files.

Once this is done, lib_dir works without issues even on linux.

I don't know if somebody have connection to the instant-client team to tell them to do that.

I will close this for issue here.