sql.connect wrongly reports a timeout when attempting to connect to a non-existing warehouse

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
48/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Quiet
Tech stack
python
Domain
backend-api-design, databases

Research direction

Start at sql.connect and the ThriftBackend retry path described in the issue, then reproduce the connection attempt against a nonexistent warehouse_id. Trace how repeated 404 responses become MaxRetryError and identify the existing exception boundary. Done means nonexistent or deleted warehouses are distinguishable from timeouts without parsing exception text, while normal retry behavior remains intact.

Written by the indexing model from the issue text.

Description

Disclaimer: I am a Databricks employee.

Calling databricks.sql.connect with a non-existing warehouse_id will raise a generic time-out exception, coming from the ThriftBackend.

It's only by digging in the source code that one can find the default of 30(!) retries - which can be set by including _retry_stop_after_attempts_count in sql.connect.

As a user of SQL Client, I'd like to easily make a distinction between a timeout (=unknown circumstances, makes more sense to retry) and a non-existing/deleted warehouse (=hard fact, makes no sense to keep trying to connect).

connection = sql.connect(
            server_hostname=server_hostname,
            http_path=f"""/sql/1.0/warehouses/{warehouse_id}""",
            credentials_provider=_credentials_provider
        )

Exception:

  
  HTTPSConnectionPool(host='[xxxx.databricks.com](http://xxxx.cloud.databricks.com/)', port=443):   
  Max retries exceeded with url: /sql/1.0/warehouses/786786d78562786  
  (Caused by ResponseError('too many 404 error responses')).

Alternatives considered

  1. One can add another dependency to the SDK and check if the Warehouse exists. It seems overkill to add the SDK just for that purpose. It really should be part of the connect client.
  2. One can parse the exception text and apply some heuristics to form an educated guess with the 404 reply. This is hacky and might have too many edge-cases. E.g. calling /sql/1.0/**warehoses**/xxxxxwould raise the exact same exception.
Dominant language
Python
Stars
233
Forks
152
Avg merge
21h 5m
Merged PRs (30d)
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