Hi all,

In order to convert tables on db1046 to the TokuDB engine - we have to schedule some downtime on the Eventlogging databases between tomorrow, Thursday Jan 21, 2016 at 16:00 UTC to Monday Jan 25, 2016 16:00 UTC.

What this means for EL users:

1. Eventlogging will still receive data and it will be available in Kafka. The data will continue to be imported into Hadoop and files.

2. The Mysql consumers of Eventlogging will be stopped, so no data will get imported into the master(db1046 or m4-master) and by extension to the analytics-store.

3. Querying existing data from analytics-store will still be available, but data for the next 4 days won't be available.

4. On Monday, after the maintenance window we'll restart the Mysql consumers, and all the data should get reimported from Kafka.

Analytics and Ops(DBA) will work on this together.

Feel free to reach out to us here or on #wikimedia-analytics if you have any concerns/questions.

-- Madhu Viswanathan

Software Engineer, Analytics