getting DPY-4000 in thin mode, add support for comma separated `net_service_name`s in tnsnames.ora

[izirku]

In our environment, tnsname.ora has many entries of form:

service_alias1.domain,
service_alias2.domain =
  (DESCRIPTION
    ...
  )

This works fine with sqlplus, many clients, and python-oracledb in thick mode. However, it doesn't work in thin mode which is required by python-oracledb for concurrent APIs.

The problem part is net_service_alias1, net_service_alias2 =, it causes a DPY-4000: unable to find "net_service_alias1" in /opt/instantclient/network/admin/tnsnames.ora error when trying to resolve net_service_alias1. It seems that python-oracledb doesn't support a list of comma separated net_service_name values.

A temporary workaround, creating "shadow" copy of tnsname.ora and removing second net_service_name:

service_alias1.domain =
  (DESCRIPTION
    ...
  )
...

, makes thin mode name resolution work. Please let me know if more details are needed! This enhancement would be a great improvement, thanks in advance!

Platform:

• RHEL9, other Linux x86_64 systems
• Python 3.12.4
• python-oracledb 2.2.1

[cjbj]

This was fixed in #3 (comment) and should work.

In fact, I can't reproduce your problem. Is there some interplay of domains, or special characters that causes it to reproduce for you?

I tried /tmp/tnsnames.ora:

service_alias1.domain,
service_alias2.domain,
mydb.x = (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=orclpdb1)))

and the code:

    connection = oracledb.connect(user=un, password=pw, config_dir='/tmp', dsn='mydb.x')

    with connection.cursor() as cursor:
        sql = """select systimestamp from dual"""
        for (r,) in cursor.execute(sql):
            print(r)

This connected and ran successfully.

[izirku]

Ok, I think, I see what's going on, only the alias closest to the = / on the same line as = gets resolved. Could you please try running it with /tmp/tnsnames.ora, but move mydb.x to a first line, and try to resolve for mydb.x?

My invocation of oracledb.connect() is exact same as yours otherwise. I just ran a couple of similar tests, and these are the findings on my end (in thin client mode):

this form doesn't resolve for mydb.x:

mydb.x,
service_alias1.domain,
service_alias2.domain = (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED) SERVICE_NAME=orclpdb1)))

while this one does resolve for mydb.x (which is not how autogenerated tnsnames.ora looks, i.e., all aliases are on separate lines when autogenerated):

mydb.x, service_alias1.domain, service_alias2.domain =
  (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=orclpdb1)))

Also, thank you for looking into this!

[cjbj]

Yep confirmed. Thanks for doing the extra investigation.

[anthony-tuininga]

I have pushed a patch that corrects this issue. If you are able to build from source you can verify that it works for you, too.

[anthony-tuininga]

This was included in python-oracledb 2.4.0 which was just released.