atoti.Session.connect

classmethod Session.connect(url, *, authentication=None, certificate_authority=None)

Connect to an existing session.

Here is a breakdown of the Live extension capabilities of the returned session:

• Local

  • If all the following conditions are met:

    • 1. the target session requires authentication (e.g. it has security configured)

    • 2. the provided authentication or certificate_authority arguments grant ROLE_ADMIN

    • 3. the target session (the one at url) was started with the same version of Atoti Python API (0.9.2)

    • 4. the target session runs on the same host as the current Python process

  • Then all Session capabilities can be used except for:

    • endpoint()

    • logs_path

    • wait()

• Remote

  • If conditions a., b., and c. are met but not d. (i.e., not on the same host)

  • Then all local capabilities are available except those needing a shared file system. For example:

    • load() with CsvLoad or ParquetLoad, read_csv(), and read_parquet() are not available (unless loading from cloud storage)

    • load() with pyarrow.Table or pandas.DataFrame, read_arrow() and read_pandas() methods are not available

• No security management

  • If conditions a. and b. are meet, plus both:

    • 5. the target session runs the same Atoti Server version (e.g. 6.1.2 for Atoti Python API 0.9.2)

    • 6. the target session is exposed to Atoti Python API

  • Depending on whether d. is met, either local or remote capabilities are available, except for security management features.

• Read-only

  • If only condition e. is met (i.e. matching Atoti Server versions)

  • Then capabilities that modify the session data or data model are unavailable. However, some read-only capabilities remain accessible. For example:

    • Not available: create_table(), create_cube(), and read_csv()

    • Available: atoti.tables.Tables.schema and atoti.Table.query()

• Minimal capabilities

  • Always available:

    • atoti.Session.link

    • atoti.Session.query_mdx

    • atoti.Cube.query

Note

Data and data model changes made from a connected session are not persisted on the target session. They will be lost if the target session is restarted.

Parameters:

• url (str) – The base URL of the target session. The endpoint f"{url}/versions/rest" is expected to exist.

• authentication (Authenticate | ClientCertificate | None) – The method used to authenticate against the target session.

• certificate_authority (Path | None) – Path to the custom certificate authority file to use to verify the HTTPS connection. Required when the target session has been configured with an SSL certificate that is not signed by some trusted public certificate authority.

Return type:

Session

Example

>>> session_config = tt.SessionConfig(security=tt.SecurityConfig())
>>> secure_session = tt.Session.start(session_config)
>>> _ = secure_session.create_table("Example", data_types={"Id": "String"})
>>> secure_session.security.basic_authentication.credentials.update(
...     {"user": "passwd", "admin": "passwd"}
... )
>>> secure_session.security.individual_roles.update(
...     {"user": {"ROLE_USER"}, "admin": {"ROLE_USER", "ROLE_ADMIN"}}
... )
>>> admin_session = tt.Session.connect(
...     secure_session.url,
...     authentication=tt.BasicAuthentication("admin", "passwd"),
... )
>>> table = admin_session.tables["Example"]
>>> table += ("foo",)
>>> table.head()
    Id
0  foo

Live extension requires the connected session to be granted ROLE_ADMIN:

>>> user_session = tt.Session.connect(
...     secure_session.url,
...     authentication=tt.BasicAuthentication("user", "passwd"),
... )
>>> list(user_session.tables)  
Traceback (most recent call last):
    ...
atoti._live_extension_unavailable_error.LiveExtensionUnavailableError: ...

Live extension requires the target session to be secure:

>>> unsecure_session = tt.Session.start()
>>> _ = unsecure_session.create_table("Example", data_types={"Id": "String"})
>>> connected_session = tt.Session.connect(unsecure_session.url)
>>> list(connected_session.tables)  
Traceback (most recent call last):
    ...
atoti._live_extension_unavailable_error.LiveExtensionUnavailableError: ...

See also

start()