Environment
sentry-cli 3.5.1 · macOS (arm64) · org: us.sentry.io
What happens
Auth, metadata fetch, and assemble POST all succeed. The upload fails only when POSTing the actual chunk payload (~5.6 MB) to /chunk-upload/, consistently after ~21 seconds:
HTTP/2 503
via: 1.1 google
upstream connect error or disconnect/reset before headers. reset reason: connection termination
Customer also reproduced on:
- Legacy endpoint via curl (POST /files/dsyms/ with a valid zip, --http1.1, -H "Expect:")
- Different network (mobile hotspot)
A tiny invalid multipart to the same endpoint returns JSON immediately, auth and routing are working
Timestamps (UTC):
2026-06-24 01:38:49 – 01:39:10 (chunk-upload)
2026-06-24 01:48:07 (legacy dsyms endpoint)
Potentially Related Issue:
#3135
Environment
sentry-cli 3.5.1 · macOS (arm64) · org: us.sentry.io
What happens
Auth, metadata fetch, and assemble POST all succeed. The upload fails only when POSTing the actual chunk payload (~5.6 MB) to /chunk-upload/, consistently after ~21 seconds:
Customer also reproduced on:
A tiny invalid multipart to the same endpoint returns JSON immediately, auth and routing are working
Timestamps (UTC):
Potentially Related Issue:
#3135