ORA-03115 on attempt to connect in Thin mode

[WolfEYc]

1. What versions are you using?
   3.0.0

db version
19.26

python output
platform.platform: macOS-15.3.2-arm64-arm-64bit
sys.maxsize > 2**32: True
platform.python_version: 3.12.7
oracledb.version: 3.0.0

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

3. What error(s) or behavior you are seeing?
   oracledb.exceptions.DatabaseError: ORA-03115: unsupported network datatype or representation

4. Does your application call init_oracle_client()?
   no

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

oracledb.create_pool_async(
user="someuser",
host="somehost",
service_name="someservicename",
password="somepassword",
port=1521,
)

I made 0 code changes, just upgrading from 2.X -> 3.x broke it.

[anthony-tuininga]

Can you e-mail me the output you get when you run your script after setting the environment variable PYO_DEBUG_PACKETS to any value?

[raphaeleicher]

Hello Anthony,

Same problem here. My code works well with oracledb 2.5.1 but not with 3.0.0.

This is my example code:

import os
import re

import ldap3
import oracledb

oid_server = os.environ.get("ORA_OIDSERVER")
dbname = os.environ.get("ORA_DBNAME")
dbuser = os.environ.get("ORA_DBUSER")
dbpass = os.environ.get("ORA_DBPASS")

# Get the Oracle Database connection string from an LDAP server when
# connection calls use an LDAP URL.

def ldap_hook(protocol, arg, params):
    pattern = r"^(.+)\/(.+)\,(cn=OracleContext.*)$"
    match = re.match(pattern, arg)
    ldap_server, db, ora_context = match.groups()

    server = ldap3.Server(ldap_server)
    conn = ldap3.Connection(server)
    conn.bind()
    conn.search(ora_context, f"(cn={db})", attributes=['orclNetDescString'])
    connect_string = conn.entries[0].orclNetDescString.value
    params.parse_connect_string(connect_string)

oracledb.register_protocol("ldap", ldap_hook)

connection = oracledb.connect(user=dbuser, password=dbpass,
             dsn=f"ldap://{oid_server}/{dbname},cn=OracleContext,dc=world")

with connection.cursor() as cursor:
    for (r,) in cursor.execute("select version from v$instance"):
        print(r)
    print(connection.version)

connection.close()

Output with oracledb 2.5.1:

$ python misc/oracledb-test.py   
19.0.0.0.0
19.24.0.0.0

Output with oracledb 3.0.0:

$ python misc/oracledb-test.py
Traceback (most recent call last):
  File "/home/myuser/projects/x/misc/oracledb-test.py", line 29, in <module>
    connection = oracledb.connect(user=dbuser, password=dbpass,
                 dsn=f"ldap://{oid_server}/{dbname},cn=OracleContext,dc=world")
  File "/home/myuser/.cache/pypoetry/virtualenvs/x-AFGDswDt-py3.13/lib/python3.13/site-packages/oracledb/connection.py", line 1257, in connect
    return conn_class(dsn=dsn, pool=pool, params=params, **kwargs)
  File "/home/myuser/.cache/pypoetry/virtualenvs/x-AFGDswDt-py3.13/lib/python3.13/site-packages/oracledb/connection.py", line 575, in __init__
    impl.connect(params_impl)
    ~~~~~~~~~~~~^^^^^^^^^^^^^
  File "src/oracledb/impl/thin/connection.pyx", line 439, in oracledb.thin_impl.ThinConnImpl.connect
  File "src/oracledb/impl/thin/connection.pyx", line 435, in oracledb.thin_impl.ThinConnImpl.connect
  File "src/oracledb/impl/thin/connection.pyx", line 395, in oracledb.thin_impl.ThinConnImpl._connect_with_params
  File "src/oracledb/impl/thin/connection.pyx", line 376, in oracledb.thin_impl.ThinConnImpl._connect_with_description
  File "src/oracledb/impl/thin/connection.pyx", line 345, in oracledb.thin_impl.ThinConnImpl._connect_with_address
  File "src/oracledb/impl/thin/protocol.pyx", line 333, in oracledb.thin_impl.Protocol._connect_phase_two
  File "src/oracledb/impl/thin/protocol.pyx", line 440, in oracledb.thin_impl.Protocol._process_message
  File "src/oracledb/impl/thin/messages.pyx", line 103, in oracledb.thin_impl.Message._check_and_raise_exception
oracledb.exceptions.DatabaseError: ORA-03115: unsupported network datatype or representation
Help: https://docs.oracle.com/error-help/db/ora-03115/

I will e-mail you the output with PYO_DEBUG_PACKETS set.

[cjbj]

Thanks - yes please email trace output.

Can you also share the actual DB version ? 19.0.0.0.0 is the release line. Can you print connection.version instead?

[raphaeleicher]

DB Version is 19.24.0.0.0.
E-maill will follow in a few minutes.

[anthony-tuininga]

Thanks. Email received. Can you also send the packet output for a successful connection with 2.5.1? Comparing them might be instructive. Thanks!

[raphaeleicher]

Of course. Mail has been sent.

[anthony-tuininga]

Thanks. Looking at that I see that the database is reporting as 19.24, not 19.26. Is that expected?

Are you able to build binaries yourself? If so, I have some thoughts you could try to see if that is the source of the issues.

[anthony-tuininga]

Question: are you able to get access to the server traces? You can do that as follows:

adrci
adrci> show base

Then from the base directory, you should see trace files in:

<base>/diag/rdbms/<db>/<inst>/trace

Hopefully the trace file reveals the source of the issue!

[raphaeleicher]

The original bug reporter has version 19.26. I have 19.24.
What binary do you expect me to build?

I don't have access to the database server, but I will ask my colleagues from the database team tomorrow.

[anthony-tuininga]

The original bug reporter has version 19.26. I have 19.24.

Thanks for clarifying.

What binary do you expect me to build?

The package for python-oracledb from source (after making some modifications). The documentation is here.

I don't have access to the database server, but I will ask my colleagues from the database team tomorrow.

Thanks.

[raphaeleicher]

The package for python-oracledb from source (after making some modifications). The documentation is here.

I think I should be able to do that.

Regarding the server traces, I've opened a ticket with my DB colleagues, but it might take a while to get a response.

[cjbj]

This reproduces against ADB-S with Transparent Application Continuity (and likely AC too).

As ADMIN, enable TAC:

SQL> execute dbms_app_cont_admin.enable_tac('[abc_cjmtls_high.adb.oraclecloud.com](http://abc_cjmtls_high.adb.oraclecloud.com/)', 'AUTO', 600);

and then connection to the service will fail with ORA-3115.

Luckily @anthony-tuininga has a patch which is being tested.

[anthony-tuininga]

I have pushed a patch that corrects this issue and have initated a build from which you can download pre-built development wheels once it completes. You can also build from source if you prefer. If you can test your scenario and confirm the patch works as expected, that would be appreciated!

[crimoniv]

Hi there! We've recently hit this bug and just found this issue.

In case it helps, testing the oracledb-3.1.0b1 wheel in our environment (python 3.12, linux, arm64) completely fixes the connection issue. Thank you very much for your support!

[cjbj]

@crimoniv it does help. Thanks for sharing your feedback.

[raphaeleicher]

I have tested your patch, and it works for us. Thanks again for your support!