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KeySessionState

Overview​

KeySessionState is an enumeration that represents the possible states of a KeySession during its lifecycle. These states help track the session's progress from initialization through connection establishment to normal operation or error conditions.

States​

START​

Initial state when the session is created. The session has been instantiated but no connection attempt has been made yet.

REGISTERING​

Session is in the process of registering with the KeyAccess server. This involves authenticating the application and establishing initial communication.

REGISTERED​

Session has successfully registered with the KeyAccess server. Authentication was successful and the session is authorized to proceed.

REGISTRATION_FAILED​

Registration with the KeyAccess server failed. This typically indicates authentication issues such as invalid API keys or unauthorized application names.

CONNECTING​

Session is connecting to the gRPC endpoint. The registration was successful and the session is now establishing the main communication channel.

DOWNLOADING_SCHEMA​

Session is downloading schema definitions from the platform. This step ensures the client has the latest data type definitions for proper serialization/deserialization.

SCHEMA_DOWNLOAD_FAILED​

Failed to download schema definitions. This may indicate network issues or problems with the schema service.

SCHEMA_DOWNLOADED​

Schema definitions have been successfully downloaded. The session now has the necessary type information for data operations.

CONNECTED​

Session is fully connected and ready for operation. All initialization steps have completed successfully and the session can now perform snapshot, subscribe, and publish operations.

DISCONNECTED​

Session is disconnected from the KeyAccess server. This can occur due to network issues, server shutdown, or explicit disconnection via stop() or stop_sync().

ERROR​

An error occurred during session operation. This is a general error state that indicates something went wrong that prevented normal operation.

Usage​

from keysquarepy import KeySession, KeySessionState

ks = KeySession(
    application_name="my-app",
    api_key="your-api-key",
    url="localhost:6800"
)

# Check current state
current_state = ks.status()

if current_state == KeySessionState.CONNECTED:
    print("Ready for data operations")
    data = ks.snapshot("Price")
elif current_state == KeySessionState.REGISTRATION_FAILED:
    print("Check your API key and application name")
elif current_state == KeySessionState.ERROR:
    print("Session encountered an error")
else:
    print(f"Session is in state: {current_state}")

State Transitions​

The typical state flow for a successful connection is:

  1. START → REGISTERING → REGISTERED → CONNECTING → DOWNLOADING_SCHEMA → SCHEMA_DOWNLOADED → CONNECTED

Possible error paths:

  • REGISTERING → REGISTRATION_FAILED
  • DOWNLOADING_SCHEMA → SCHEMA_DOWNLOAD_FAILED
  • Any state → ERROR (for unexpected errors)
  • CONNECTED → DISCONNECTED (on normal shutdown or network issues)

See Also​