Bug #20447
Updated by Peter Amstutz 12 months ago
I need to look at postgres status to see what is going on, but I have a theory:
# We put a "big lock" around the containers table, all write operations have to take an exclusive lock on the table (unfortunately this includes container operations that don't affect priorities, but maybe it's possible to make this )
# This means all container operations now have to wait to get the lock
# We also added a feature whereby each time a "running containers probe" happens, it updates the "cost" on the API server
# This means write operations on containers are now happening much much more frequently than just when containers change state
# As a result, requests involving containers are forced to wait in line, filling up the request queue and making everything slow.
On the plus side, the behavior of the dispatcher to back off when it sees 500 errors seems to be successfully keeping the system load from spiraling out of control.
This also suggests a short term fix to system load is to increase ProbeInterval.