explore_json return error that 'an error occured'

explore_json return error with this content an error occurred for queries that approximately takes time more than ‘00:01:57’ while the query returns in the sql_lab. This issue happens while I increased the webserver timeout and it’s big enough for that!

Expected results

Show table in explore_json

Actual results

Superset just returns error with this content: an error occured

Screenshots

How to reproduce the bug

1. Go to
2. Click on ‘…’
3. Scroll down to ‘…’
4. See error

Environment

(please complete the following information):

• superset version: master branch from 3 weeks ago
• python version: 3.6

Checklist

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• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven’t found one similar.

Additional context

Add any other context about the problem here.

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[prajamani]

SUPERSET_WEBSERVER_TIMEOUT is set to 120 seconds.

gunicorn timeout is set to 150 seconds.

gunicorn
–bind “0.0.0.0:8088”
–workers $((2 * $(getconf _NPROCESSORS_ONLN) + 1))
-k gevent
–timeout 150
–limit-request-line 0
–limit-request-field_size 0
–access-logfile ‘-’
–error-logfile ‘-’
superset:app

I’m still getting random timeouts (15 secs, 22 secs,.). Here’s the error we get in the browser as the connection gets dropped by the webserver.

POST superset/explore_json/?form_data=%7B%22slice_id%22%3A62%7D&force=true net::ERR_EMPTY_RESPONSE TypeError: Failed to fetch

Do we need any specific timeout setting in ngnix for the above SUPERSET_WEBSERVER_TIMEOUT and gunicorn timeout settings to work ?