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This guide focuses on Node Core Dump Analysis for production systems, with practical trade-offs for reliability, security, and cost.
Native addons and sharp/libc bugs still SIGSEGV Node in production. Without cores you only see “Runtime exited.” The unfair advantage is controlled core capture on ECS: ulimit + pattern to EFS/S3, matching debug symbols, scrubbing, then lldb/gdb—never leaving dumps with customer payloads on shared disks.
⚡ TL;DR: Setulimit -candkernel.core_pattern(or ECS-compatible path); ship breakpad/async-profiler only when needed; symbolicate with the exact Node build +.nodeaddon symbols; PII-scrub before ticket attach. Pair with N-API Addons for Node and Ephemeral Debug Sidecars.
Node Core Dump Analysis: production guidance
bash
# ✅ Entry script (ECS)
ulimit -c unlimited
# Write to mounted volume, not overlay
echo "/cores/core.%e.%p.%t" > /tmp/core_pattern_hint
# Prefer host/sysctl managed by platform team:
# kernel.core_pattern = |/usr/lib/systemd/systemd-coredump OR /var/cores/core.%e.%p
export NODE_OPTIONS="--abort-on-uncaught-exception" # optional; native faults dump regardless
dockerfile
# ✅ Keep a debug image with matching symbols (not in prod by default)
FROM public.ecr.aws/docker/library/node:20-bookworm
RUN apt-get update && apt-get install -y gdb lldb binutils \
&& mkdir -p /cores
# Copy exact addon .node + .debug files from CI artifacts
Symbolicate the crash
bash
# ✅ gdb batch against core + node binary from the same build
gdb /usr/local/bin/node /cores/core.node.83.171000 \
-batch \
-ex "set pagination off" \
-ex "bt" \
-ex "thread apply all bt" \
-ex "info sharedlibrary"
| Artifact | Why required |
|---|---|
Exact node binary |
Frames won’t resolve otherwise |
Addon .node + debug symbols |
Most segfaults are native |
| libc/libstdc++ from image | Deep frames |
| Build-id / VCS SHA | Prove match |
typescript
// ❌ Shipping alpine prod + debugging with debian node — addresses never match
Scrub before share
Cores contain heap → tokens, PII, documents. Pipeline: encrypt at rest on the core volume → analyst pulls via audited sidecar → run strings allowlist / redact → attach only backtrace + module list to the ticket.bash
# ✅ Minimal shareable artifact
gdb ... -ex "bt" | tee stack.txt
# Do not upload raw core to Slack/Jira
Closing checklist
✅ Dos – ✅ Platform-owned core pattern + retention (24–72h) – ✅ CI publish debug symbols keyed by build-id – ✅ Rate-limit dump capture (one per task family / hour) – ✅ Use ephemeral debug sidecars for interactive gdb – ✅ Reproduce under ASAN/UBSAN in staging for addon bugs ❌ Don’ts – ❌ Don’t enable unlimited cores on tiny ephemeral disks – ❌ Don’t paste core files into chat – ❌ Don’t analyze with mismatched Node builds – ❌ Don’t ignore addon version skew after “only JS changed” deploysRelated reading
- N-API Addons for Node: Move Hot Loops Off the Event Loop
- Ephemeral Debug Sidecars: Audited Access Without Permanent Prod Shells
- Node Heap Snapshots in Production
- Lambda Versioned Layers: Native Node Addons
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