Frequent "Results Expired" while running Impala Queries on HUE Notebook

[#1]

We are using CDH 5.10.1, and notice frequent exceptions in HUE, when running Impala Queries in Notbook.

Results Expired. Rerun quries to get results.

Any idea, why this is happening, and what can be done to resolve it?

Our Hive Metastore is PostgreSQL

[#2]

Hello,

Receiving "Results Expired" error in Hue for Impala queries, is usually a symptom of having a misconfigured load-balancer in front of Impala.

Impala has the assumption, that the query results will be downloaded from the same impalad where the query was issued. A load-balancer can break that assumption, if it sendis sequential connections of the same client to different impalad daemons. If Hue connects two a different impalads to run the query and download the results, the "Results Expired" error will appear.

To avoid the above issue, it's required that the proxy routes subsequent connections of the same client to the same impalad. This proxy behavior is usually called sticky sessions. Our documentation has detailed information about impala load-balancer setup, includeing the above information as well:
https://www.cloudera.com/documentation/enterprise/latest/topics/impala_proxy.html#proxy_overview