Random Error 1102 (“Worker exceeded resource limits”) but metrics show low CPU. How do I debug this?
Summary / context
- Stack: hono + trpc serving a React Router 7 app.
- I intermittently get Error 1102 when visiting the site: “Worker exceeded resource limits”.
- I attached two screenshots: Worker metrics and the 1102 error page.
- I read the CPU time docs (link: https://developers.cloudflare.com/workers/platform/limits/#cpu-time).
What’s confusing
- In Metrics/Logs I don’t see any request taking more than ~300–400 ms end-to-end.
- CPU time percentiles look tiny: P50 ~62 ms, P90 ~104 ms, P99/P999 ~127 ms.
- Wall/request duration is also low (median ~165 ms, P99 ~383 ms).
- I can’t find a stack trace or any clear error log for the failing invocation.
What I’ve tried
- Looked for long/slow requests in Logs and Analytics → nothing stands out.
- Searched code for obvious infinite loops or recursion; nothing obvious yet.
- I don’t have a custom cpu_ms limit set (so default 30s).
- I’m not sure how to correlate that Ray ID to a specific failing code path—logs seem to be missing for that run.
Questions
- What’s the best way to debug a single 1102 event? Can I reliably trace by Ray ID and see CPU/wall time per invocation even if the isolate was killed?
- Are there common gotchas that cause 1102 despite low percentile metrics—e.g., self--fetch recursion due to routing, asset proxying, or SSR patterns? Any recommended checks to confirm/deny that?
- Is there a way to enable per-invocation trace events or a CPU profile that survives termination?
- Any other settings or Wrangler commands I should use to surface the failing branch (e.g., temporary low cpu_ms, specific logging flags)?
Attachments
- Screenshot 1: Worker metrics (CPU Time, Wall Time, Request duration showing the sub-400ms percentiles)
- Screenshot 2: Error 1102 page with the Ray ID above
Thanks in advance!
- Stack: hono + trpc serving a React Router 7 app.
- I intermittently get Error 1102 when visiting the site: “Worker exceeded resource limits”.
- I attached two screenshots: Worker metrics and the 1102 error page.
- I read the CPU time docs (link: https://developers.cloudflare.com/workers/platform/limits/#cpu-time).
What’s confusing
- In Metrics/Logs I don’t see any request taking more than ~300–400 ms end-to-end.
- CPU time percentiles look tiny: P50 ~62 ms, P90 ~104 ms, P99/P999 ~127 ms.
- Wall/request duration is also low (median ~165 ms, P99 ~383 ms).
- I can’t find a stack trace or any clear error log for the failing invocation.
What I’ve tried
- Looked for long/slow requests in Logs and Analytics → nothing stands out.
- Searched code for obvious infinite loops or recursion; nothing obvious yet.
- I don’t have a custom cpu_ms limit set (so default 30s).
- I’m not sure how to correlate that Ray ID to a specific failing code path—logs seem to be missing for that run.
Questions
- What’s the best way to debug a single 1102 event? Can I reliably trace by Ray ID and see CPU/wall time per invocation even if the isolate was killed?
- Are there common gotchas that cause 1102 despite low percentile metrics—e.g., self--fetch recursion due to routing, asset proxying, or SSR patterns? Any recommended checks to confirm/deny that?
- Is there a way to enable per-invocation trace events or a CPU profile that survives termination?
- Any other settings or Wrangler commands I should use to surface the failing branch (e.g., temporary low cpu_ms, specific logging flags)?
Attachments
- Screenshot 1: Worker metrics (CPU Time, Wall Time, Request duration showing the sub-400ms percentiles)
- Screenshot 2: Error 1102 page with the Ray ID above
Thanks in advance!
Welcome to the official Cloudflare Developers server. Here you can ask for help and stay updated with the latest news
86,942Members
Resources
Was this page helpful?
