I'm calling an Impala query paragraph in a Zeppelin note, using the REST API (so I can parse the returned data in Javascript) and it works fine some of the time, and other times it fails with a 502 proxy error. The same paragraph run via the Zeppelin UI always works fine.   I'm running it synchronously as per: https://zeppelin.apache.org/docs/0.8.2/usage/rest_api/notebook.html#run-a-paragraph-synchronously   How would I go about fault finding on this please? I'm unsure where to start. Or, is there another way I can access the data, it looks to me like the asynchronous method will not return any data, just a status? https://zeppelin.apache.org/docs/0.8.2/usage/rest_api/notebook.html#run-a-paragraph-asynchronously ... View more