Edit: This used to be punctual at some point, now it is causing generalized edit slowdowns and inability to read recentchanges/watchlists on several wikis.
The most impacted ones are s2 and s7, but looks generalized? https://grafana.wikimedia.org/dashboard/db/mysql-replication-lag?orgId=1&from=1493556218361&to=1493577818361&var-dc=codfw%20prometheus%2Fops
It started at 16:57 2017-04-30 and multiplied db network usage 10 times: https://grafana.wikimedia.org/dashboard/db/mysql-aggregated?orgId=1&from=1493569412579&to=1493572762650&var-dc=eqiad%20prometheus%2Fops&var-group=core&var-shard=s1&var-shard=s2&var-shard=s3&var-shard=s4&var-shard=s5&var-shard=s6&var-shard=s7&var-role=master
But the edit rate doesn't seem too crazy.
I do not expect this to create continued issues- but wanted to report it and see if there is something to improve/tune about async processing speed.
Edit: Varnish doesn't look happy at that time: https://grafana.wikimedia.org/dashboard/db/varnish-traffic?refresh=5m&panelId=10&fullscreen&orgId=1&from=1493486799140&to=1493638662298
Edit2 Apparently varnish is ok with the load