as part of https://phabricator.wikimedia.org/T183297 the Analytics team is migrating all the Varnishkafka Eventlogging traffic from Kafka Analytics to Kafka Jumbo. The procedure that we are going to use is the following:

1) change the varnishkafka configuration - this will effectively migrate all the traffic from the caching hosts to Kafka Jumbo.

2) eventlogging keeps pulling data from the Kafka analytics topics until it consumes all the events.

3) change eventlogging's config to pull data from Kafka Jumbo.

This change should not cause any data loss or inconsistency but we had to create new dashboards:

- https://grafana.wikimedia.org/dashboard/db/eventlogging and https://grafana.wikimedia.org/dashboard/db/eventlogging-schema are still pointing to the analytics cluster, so they will likely show a big drop after the migration. I added a big banner explaining what's happening in both.

- https://grafana.wikimedia.org/dashboard/db/eventlogging-jumbo and https://grafana.wikimedia.org/dashboard/db/eventlogging-schema-jumbo point to the new Kafka Jumbo cluster, so they should soon start showing data. Those dashboards are still work in progress so for every inconsistency please follow up with me (elukey) or Andrew (ottomata) on #wikimedia-analytics.

Thanks!

Luca (on behalf of the Analytics team)