Wikimedia wikis hosted on the "s3" cluster (pretty much all but the very large wikis, click on the "s3" box in https://noc.wikimedia.org/dbtree/ to get a full list) are currently in read-only mode due to severe replication lag. This problem was apparently caused by a logic issue in the job queue, which should now be fixed, but it will still take at least 2-3 hours for replication to catch up. We apologize for the inconvenience, and are continuing to monitor the situation. Erik -- Erik Möller VP of Engineering and Product Development, Wikimedia Foundation Support Free Knowledge: https://wikimediafoundation.org/wiki/Donate