Log signatures

V8 JavaScript heap OOM (Node)

FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory

or

<--- Last few GCs --->
<--- JS stacktrace --->
FATAL ERROR: Ineffective mark-compacts near heap limit

Exit code: often 134 (SIGABRT on Unix)

Mitigation (temporary): NODE_OPTIONS=--max-old-space-size=4096 — buys time, does not fix leak.

Container OOMKilled (Kubernetes / Docker)

State: Terminated
Reason: OOMKilled
Exit Code: 137

Kernel killed process — may not include JS stack trace.

Check kubectl describe pod → Last State, memory limits vs rss metrics.

Browser tab crash

Chrome: “Aw, Snap!” / error code RESULT_CODE_KILLED — often after long leak session.

Less explicit than Node — use Performance monitor before crash.

GC pressure warnings (smell, not proof)

(node) WARNING: Excessive number of pending callbacks
MaxListenersExceededWarning

Investigate — often correlates with listener/timer leaks.

flowchart TD
  logs[Log line]
  jsOOM[V8 heap OOM exit 134]
  kubeOOM[OOMKilled exit 137]
  logs --> jsOOM
  logs --> kubeOOM
  jsOOM --> fix[Fix retention in code]
  kubeOOM --> fix

Don’t only raise heap limit

Increasing --max-old-space-size without fixing the leak delays crash, increases blast radius.