Briefly, this error occurs when Elasticsearch encounters an issue while trying to clean up an upload, identified by its uploadId, of a blobKey. This could be due to a variety of reasons such as insufficient permissions, network issues, or a corrupted blob. To resolve this issue, you can try the following: 1) Check and ensure that Elasticsearch has the necessary permissions to perform the cleanup. 2) Verify your network connectivity. 3) Try to identify and repair the corrupted blob, or delete and re-upload it if necessary.
This guide will help you check for common problems that cause the log ” unexpected error cleaning up upload [” + uploadId + “] of [” + blobKey + “] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: repository-s3, repositories.
Overview
An Elasticsearch snapshot provides a backup mechanism that takes the current state and data in the cluster and saves it to a repository (read snapshot for more information). The backup process requires a repository to be created first. The repository needs to be registered using the _snapshot endpoint, and multiple repositories can be created per cluster. The following repository types are supported:
Repository types
| Repository type | Configuration type |
|---|---|
| Shared file system | Type: “fs” |
| S3 | Type : “s3” |
| HDFS | Type :“hdfs” |
| Azure | Type: “azure” |
| Google Cloud Storage | Type : “gcs” |
Examples
To register an “fs” repository:
PUT _snapshot/my_repo_01
{
"type": "fs",
"settings": {
"location": "/mnt/my_repo_dir"
}
}Notes and good things to know
- S3, HDFS, Azure and Google Cloud require a relevant plugin to be installed before it can be used for a snapshot.
- The setting, path.repo: /mnt/my_repo_dir needs to be added to elasticsearch.yml on all the nodes if you are planning to use the repo type of file system. Otherwise, it will fail.
- When using remote repositories, the network bandwidth and repository storage throughput should be high enough to complete the snapshot operations normally, otherwise you will end up with partial snapshots.
Log Context
Log “unexpected error cleaning up upload [” + uploadId + “] of [” + blobKey + “]” classname is S3BlobContainer.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
if (isComplete.compareAndSet(false; true)) {
try {
abortMultipartUploadIfExists(uploadId);
} catch (Exception e) {
// cleanup is a best-effort thing; we can't do anything better than log and fall through here
logger.error("unexpected error cleaning up upload [" + uploadId + "] of [" + blobKey + "]"; e);
assert false : e;
}
}
};
