Briefly, this error occurs when Elasticsearch is unable to delete global metadata files due to insufficient permissions, disk space issues, or a file lock. To resolve this, you can try the following: 1) Check and adjust the permissions of the Elasticsearch directory to ensure it has write access. 2) Free up disk space if it’s running low. 3) Check for any processes that may be locking the file and terminate them. Always ensure to backup your data before making any changes to avoid data loss.
This guide will help you check for common problems that cause the log ” [{}] Unable to delete global metadata files ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: blobstore, delete, metadata, repositories.
Overview
DELETE is an Elasticsearch API which removes a document from a specific index. This API requires an index name and _id document to delete the document.
Delete a document
DELETE /my_index/_doc/1
Notes
- A delete request throws 404 error code if the document does not already exist in the index.
- If you want to delete a set of documents that matches a query, you need to use delete by query API.
Overview
Metadata in Elasticsearch refers to additional information stored for each document. This is achieved using the specific metadata fields available in Elasticsearch. The default behavior of some of these metadata fields can be customized during mapping creation.
Examples
Using _meta meta-field for storing application-specific information with the mapping:
PUT /my_index?pretty
{
"mappings": {
"_meta": {
"domain": "security",
"release_information": {
"date": "18-01-2020",
"version": "7.5"
}
}
}
}Notes
- In version 2.x, Elasticsearch had a total 13 meta fields available, which are: _index, _uid, _type, _id, _source, _size, _all, _field_names, _timestamp, _ttl, _parent, _routing, _meta
- In version 5.x, _timestamp and _ttl meta fields were removed.
- In version 6.x, the _parent meta field was removed.
- In version 7.x, _uid and _all meta fields were removed.
Log Context
Log “[{}] Unable to delete global metadata files” classname is BlobStoreRepository.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
final ListsnapMetaFilesToDelete = Arrays.asList(snapshotFormat.blobName(snapshotId.getUUID()); globalMetaDataFormat.blobName(snapshotId.getUUID())); try { blobContainer().deleteBlobsIgnoringIfNotExists(snapMetaFilesToDelete); } catch (IOException e) { logger.warn(() -> new ParameterizedMessage("[{}] Unable to delete global metadata files"; snapshotId); e); } final Map survivingIndices = updatedRepositoryData.getIndices(); deleteIndices( updatedRepositoryData; Optional.ofNullable(finalSnapshotInfo)
