Free bytes on the volume holding run artifacts, or null when it cannot be read.
The ceiling V8 will not grow past — --max-old-space-size, or the platform default.
V8 heap in use, bytes.
0..1. Above ~0.9 a long sync is usually already in trouble.
Host RAM, total and actually allocatable. Null off Linux or when /proc is unreadable.
Resident set: what the CONTAINER sees, which is what an OOM killer acts on.
Resident set as a fraction of host RAM — the number the OOM killer effectively acts on.
This exists because HeapUsedFraction cannot see the memory that actually kills a sync.
--max-old-space-size bounds V8's OLD SPACE only; Buffer/ArrayBuffer — where an HTTP
response body lives before it is parsed — is external and counted in neither. Proven on the
sandbox 2026-09-14: the kernel killed node at 3,478 MB RSS on a 3,830 MB box against a
1,964 MB heap ceiling (1.8x), while heap usage was unremarkable. A throttle watching only
the heap reads healthy right up to the kill.
Retained run directories, against the retention cap that prunes them.
Free bytes on the volume RSU writes migrations and compiles into.
Syncs this process is currently running.