Intermittent SQL Failure on Databricks SQL Warehouse

Ramakrishnan83 — Mon, 15 Apr 2024 17:12:35 GMT

Team,

I did setup a SQL Warehouse Cluster to support request from Mobile devices through REST API. I read through the documentation of concurrent query limit which is 10. But in my scenario I had 5 small clusters and the query monitoring indicated there is not peak load or query being queued. But however the front end initiate 2 queries at the same time to 2 different tables(Select query). No complex joins or transformation in the select statement. These 2 queries gets executed most the of the time in less than a second. But there are scenarios where only one query completes in average of 10-11 seconds and the second query stays in the "Executing" phase and gets time out after 120 seconds.

The same query gets completed next time if the request comes in. So it is not about the query or data. I am not able to track out why the query fails as the query monitor is also not having much information.

I would like to understand:

1. Does databricks SQL Support concurrent read request ? if yes, what is definition of concurrency?

10 read request hitting at the same second/millisecond or max 10 request is processed by the cluster.

2. Does Databricks SQL has logging to trace back the request from the time it hit the SQL Warehouse to completion?

Re: Intermittent SQL Failure on Databricks SQL Warehouse

198270 — Thu, 17 Oct 2024 16:59:24 GMT

We have a similar problem: our self service BI tool Looker is using SQL warehouse and queries that usually run in a few seconds randomly fail with this message (logged in Looker history explore) "Java::JavaSql::SQLException: [Databricks][JDBCDriver](500580) Operation is canceled.".

We're talking about <1% of queries, but it's still something that we would like to avoid.

My suspicion is also that it is related to concurrency settings of the SQL warehouse.

I couldn't find anything in the docs or in threads about configuring concurrency settings for SQL warehouses.

Can you please help?

topic Re: Intermittent SQL Failure on Databricks SQL Warehouse in Warehousing & Analytics

Intermittent SQL Failure on Databricks SQL Warehouse

Re: Intermittent SQL Failure on Databricks SQL Warehouse