Snowflake connection times out in Data Virtualization

A Snowflake connection in Data Virtualization might time out with an authentication token expiry message.

Symptoms

This issue occurs when you establish a Snowflake connection and do not use it for some period of time (4 hours by default). Preview of virtual data asset in Watson Knowledge Catalog is unavailable, preview of virtual data asset in Virtualized data is unavailable, and the Virtualize page might become unresponsive.

If the CLIENT_SESSION_KEEP_ALIVE parameter is not set or is set to FALSE, the Snowflake driver does not keep the connection alive and after 4 hours of inactivity, the token expires. This authentication expiration causes all subsequent queries to fail in Data Virtualization.

When you preview virtual assets in IBM Knowledge Catalog or preview them on the Virtualized data page, you might notice the following error message:

2021-07-07 15:28:34.382 2021-07-07 15:21:56.285 3 RESULT_DS_EXEC_QUERY_ERROR: Query exec 
failure against Data Source GDB_SUBQ_SNOWF10020: java.lang.Exception: Unable to get physical 
meta data for table: : net.snowflake.client.jdbc.SnowflakeReauthenticationRequest: 
Authentication token has expired. The user must authenticate again.

Resolving the problem

Add the configuration CLIENT_SESSION_KEEP_ALIVE=TRUE to the Snowflake connection.