Backup with Attachments Fails with 503 Service Unavailable Error

Backups that include attachments may fail with a 503 Service Unavailable error after the backup has progressed to approximately 50%.

The issue occurs during the processing of large attachment volumes. The backup successfully uploads the attachment data, but subsequent processing can trigger excessive requests to the storage service, resulting in temporary service unavailability.

This is more likely to occur when the backup contains a large number of attachments and temporary metadata files.

Steps to Reproduce

1. Start a backup that includes attachments.
2. Allow the backup to process a large volume of attachments.
3. Monitor the backup progress.
4. The backup may fail at approximately 50% progress with a 503 Service Unavailable error.

Expected Result

The backup should complete successfully without returning a 503 error, regardless of the number of attachments being processed.

Actual Result

The backup may fail with a 503 Service Unavailable error while processing attachments, preventing the backup from completing successfully.

Impact

Customers with large backups containing many attachments may be unable to complete the backup successfully.

The issue is primarily observed with backups generating a large number of temporary metadata files.

Workaround

As a temporary workaround, customers can reduce the size of individual backups by splitting the data into smaller backups, such as by project or date range.

Backups without attachments are not affected by this issue.