Findings for one reading. The memory line is host RAM in use as a fraction of host RAM, above
which a sync is heading for an OOM kill.
Lower than the heap threshold on purpose. The heap ceiling is a wall V8 enforces, so 0.85 of it
still leaves the process alive to checkpoint. The host has no such wall — crossing it is a
SIGKILL with no stack, no run record and no chance to save a watermark, so the warning has to
arrive with enough headroom left to actually shed load.
It is the governor's line (SHED_ABOVE_FRACTION, or the operator override), read at call time
from ResolveThresholds so the two cannot diverge, and judged on the same reading — memory in
use on the host. It used to be 0.70 of this process's RSS, which a workspace whose heap is sized
at (RAM - 1 GB) x 0.70 crosses just by booting.
Findings for one reading. The memory line is host RAM in use as a fraction of host RAM, above which a sync is heading for an OOM kill.
Lower than the heap threshold on purpose. The heap ceiling is a wall V8 enforces, so 0.85 of it still leaves the process alive to checkpoint. The host has no such wall — crossing it is a SIGKILL with no stack, no run record and no chance to save a watermark, so the warning has to arrive with enough headroom left to actually shed load.
It is the governor's line (
SHED_ABOVE_FRACTION, or the operator override), read at call time fromResolveThresholdsso the two cannot diverge, and judged on the same reading — memory in use on the host. It used to be 0.70 of this process's RSS, which a workspace whose heap is sized at (RAM - 1 GB) x 0.70 crosses just by booting.