Hi Analytics,

Next Tuesday, Dec 15, between 10:00 and 12:00 UTC

EventLogging's database m4-master will be down for maintenance.

Impact of the outage:

Events generated during the mentioned time window will wait until the outage is over to be inserted in the m4-master database. These events and the ones generated immediately after the outage can take a couple hours to catch up and be inserted.

Everything else should work as normal during the outage:

Events can be sent normally to EventLogging server, they'll be buffered in Kafka.
Events will be written to the logs, and forwarded to other systems normally. The only process that will stop is the mysql-consumer.
Queries to analytics-store can be executed normally. The outage is local to m4-master and does not affect replicas.

Feel free to ask any questions you have on this.

Cheers!

Marcel Ruiz Forns

Analytics Developer

Wikimedia Foundation