WebSocket Protocol Version

PyExasol is based on the WebSocket protocol.

Exasol has the concept of “protocol version” which is used to extend the functionality of new database drivers without breaking the backwards compatibility with older database drivers.

When a client (e.g. PyExasol) opens the connection with the Exasol server, it sends the requested protocol version during the authorisation. Exasol server may or may not support the requested protocol version. If an Exasol server does not support the requested version, it will downgrade the protocol version automatically. To check the actual protocol version of connection, use pyexasol.ExaConnection:protocol_version().

For a list of Websocket protocol versions supported by specific Exasol DB versions, see Supported Versions.

If a user is using an older Exasol DB version like 6.25 and has an error like Could not create WebSocket protocol version, modify the protocol_version parameter in pyexasol.connect() or pyexasol.ExaConnection to a supported version.