Post Mortem: Ceph v18.2.7 OSD High CPU Usage Caused by the Messenger
· 11 min read
A single object was being requested by >100 clients triggered the messenger to throttle on one OSD, causing CPU to spike above 300% and cause slow operations across unrelated PGs. We trace the root cause to the osd_client_message_cap throttle and its interaction with a known upstream bug Ceph Tracker #62512.
