Deephaven Core+ Python Client

The Deephaven Core+ Python client allows you to connect to Persistent Queries using the Core+ engine in the Deephaven Enterprise system. You may connect to either a new temporary Persistent Query, or one of the existing persistent queries that you have access to on the server.

The Python client wheel is located on a Deephaven server in /usr/illumon/coreplus/latest/py/wheel/, with a name of the form deephaven_coreplus_client-1.20231218.039-py3-none-any.whl. To use the wheel, use pip (e.g., pip install deephaven_coreplus_client-1.20231218.039-py3-none-any.whl). pip automatically installs dependencies referenced by the wheel, including the underlying pydeephaven client from Deephaven Community Core.

The first step in either case is to create a SessionManager, the Deephaven installation exposes a connection.json file that is the simplest way to create a session. Simply specify the URL from your Deephaven installation. Alternatively, you may provide a JSON string, using the json= named parameter.

from deephaven_enterprise.client.session_manager import SessionManager

connection_info = "https://deephaven-host.int.illumon.com:8000/iris/connection.json"
session_mgr: SessionManager = SessionManager(connection_info)

After the session is created, you may authenticate with a password:

session_mgr.password("username", "password")

Or using a private key:

session_mgr.private_key("/path-to-private-key/priv-username.base64.txt")

At this point, you can then connect to an existing Persistent Query. The session object extends from the Deephaven Community pydeephaven.session.Session. The Deephaven Community Python API documentation provides more information on interacting with the worker session.

session = session_mgr.connect_to_persistent_query("Community Python")
qc = session.open_table("tt")
print("Table size: ", qc.size)
session.close()

Instead of connecting to an existing Persistent Query, you can instead make a new temporary persistent query to host your worker.

session = session_mgr.connect_to_new_worker(name=None, heap_size_gb=1.0)

# We can run arbitrary script code
session.run_script('from deephaven import time_table\n'
                   'tt = time_table("PT1s").update("Remote=false")')

table = session.time_table(period=1000_000_000).update("Remote=true")
session.bind_table("remote", table)

session.close()

You can interact with the session through the Community Python API and view tables with the Deephaven Web UI. By default, the temporary queries are stopped and deleted after you close the session object.