What is MinIO InvalidPart error encountered during multipart upload.

Resolving the 'InvalidPart' Error in MinIO

Understanding MinIO and Its Purpose

MinIO is a high-performance, distributed object storage system designed to handle unstructured data such as photos, videos, log files, backups, and container images. It is compatible with Amazon S3 cloud storage service, making it a popular choice for developers looking for a scalable and efficient storage solution.

Identifying the Symptom: 'InvalidPart' Error

When working with MinIO, you might encounter the 'InvalidPart' error during a multipart upload. This error indicates that one or more parts of the upload are invalid. The error message typically appears as follows:

Error: InvalidPart: One or more parts in the multipart upload are invalid.

This error can disrupt the upload process, preventing the successful storage of your data.

Exploring the 'InvalidPart' Issue

The 'InvalidPart' error occurs when there is an inconsistency in the parts being uploaded. This could be due to incorrect part numbers, mismatched sizes, or corrupted data. Multipart uploads are designed to handle large files by splitting them into smaller parts, which are uploaded separately and then reassembled. Any discrepancy in this process can lead to the 'InvalidPart' error.

Common Causes of the Error

Incorrect part numbers: Each part must have a unique part number. Size mismatch: The size of each part must match the expected size. Corrupted data: Data corruption during upload can lead to invalid parts.

Steps to Fix the 'InvalidPart' Error

To resolve the 'InvalidPart' error, follow these steps:

1. Verify Part Numbers

Ensure that each part of the upload has a unique and sequential part number. Part numbers should start from 1 and increment by 1 for each subsequent part. Use the following command to list the parts and verify their numbers:

mc ls myminio/mybucket/myobject

2. Check Part Sizes

Confirm that each part's size matches the expected size. If a part is incomplete or too large, it may cause the error. Use the following command to check the size of each part:

mc stat myminio/mybucket/myobject/part1

Repeat this for each part to ensure consistency.

3. Re-upload Corrupted Parts

If you suspect data corruption, re-upload the affected parts. You can use the MinIO client (mc) to re-upload specific parts:

mc cp /local/path/to/part1 myminio/mybucket/myobject/part1

Ensure that the local file is intact before re-uploading.

Additional Resources

For more information on multipart uploads and troubleshooting, refer to the following resources:

MinIO Client Complete Guide Amazon S3 Multipart Upload Overview

By following these steps, you should be able to resolve the 'InvalidPart' error and ensure a smooth multipart upload process in MinIO.