R2 elevated errors during CompleteMultipart operations

Resolved

This incident has been resolved.

Update

We've deployed a fix for the multipart uploads that were failing on Complete Multipart calls, and error rates have returned to normal levels. We will continue monitoring impact.

Update

We've isolated the pattern leading to Multipart Uploads that are erroring during CompleteMultipartUploads and are preparing a fix for those requests.

Investigating

Cloudflare has observed an increase in HTTP 500 responses on some CompleteMultipart API requests containing parts uploaded between 21:03 and 21:26 UTC. We are working to analyze and mitigate this problem. More updates to follow shortly.