Today I made a little test in our staging instance, namely commenting DRUID_IS_ACTIVE = True in the superset_config.py file. This caused the following:

1. Druid datasources disappeared from the main dropdown menu', leaving only the "Table" ones (so the ones defined via SQLAlchemy)
2. The charts using the Druid datasources are still visible, but clicking on the datasource itself leads to a 404 (since a migration to the Druid tables is needed).

So in theory we could start this migration by simply turning off the Druid datasource support, to avoid new charts to be created with the old settings, and then ask people to migrate their chart slowly. I'll follow up with Product Analytics for some tests, but it looks promising!

Change 658228 had a related patch set uploaded (by Elukey; owner: Elukey):
[operations/puppet@production] superset: disable old druid datasouce panels

https://gerrit.wikimedia.org/r/658228

Added https://wikitech.wikimedia.org/wiki/Analytics/Systems/Superset#Migrate_a_chart_to_Druid_tables

Change 658228 merged by Elukey:
[operations/puppet@production] superset: disable old druid datasouce panels

https://gerrit.wikimedia.org/r/658228

Mentioned in SAL (#wikimedia-analytics) [2021-01-25T10:18:48Z] <elukey> restart superset to remove druid datasources support - T263972

@elukey is this task complete?

@odimitrijevic it is not, last time that I checked there was some usage of Druid datasources. We should do the following:

• review what dashboards are still using Druid datasources
• move to Druid tables

The main motivation is that upstream doesn't support anymore the old Druid datasource way, and upgrading is a pain in case we encounter a bug (a dashboard might break and upstream will not fix the bug etc..).