When we process Event Logging events, we hash the origin IP address and add
it to the event as part of the "capsule. We salt the hash function and
rotate the salt frequently for security, but within those periods of time
the same IP would get hashed to the same hash, and some people depended on
We recently made the Event Logging processor parallel, and we accidentally
forgot to make this hashing consistent across all the parallel instances.
So from September 10, 2015 until we fix the bug, client IPs will not be
We are tracking this issue here: https://phabricator.wikimedia.org/T112688
If you have some data crunching that's affected by this, come talk to us.
We are already adding a temporary fix to the scripts that generate the
edit-analysis dashboard