Hi Analytics,
Yesterday, Dec 15, during the course of 1 hour (17h to 18h UTC) there was an irrecoverable raw_webrequest data loss of ~30%: 25.6% (misc), 19.5% (mobile), 19.1% (text), 39.1% (upload). This represents around 1% of the data for that day.
The loss was due to the enabling of IPSec, which encrypts varniskafka traffic between caches in remote datacenters and the Kafka brokers in eqiad. During a period of about 40ish minutes, no webrequest logs from remote datacenters were successfully produced to Kafka.
Here's the outage note: https://wikitech.wikimedia.org/wiki/Analytics/Data/Webrequest#Changes_and_kn... Sorry for the inconvenience.