Briefly, this error occurs when Elasticsearch is unable to delete the metadata for a specific index. This could be due to insufficient permissions, a locked index, or a network issue. To resolve this, you can try the following: 1) Check and adjust the user permissions to ensure they have the necessary rights to delete metadata. 2) Unlock the index if it’s locked. 3) Check your network connection and ensure Elasticsearch cluster is accessible. 4) If the issue persists, consider restarting the Elasticsearch node.
This guide will help you check for common problems that cause the log ” [{}] failed to delete metadata for index [{}] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: metadata, blobstore, delete, repositories, index.
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.
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.
Log Context
Log “[{}] failed to delete metadata for index [{}]” classname is BlobStoreRepository.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
private void deleteIndexMetaDataBlobIgnoringErrors(SnapshotId snapshotId; IndexId indexId) {
try {
indexMetaDataFormat.delete(indexContainer(indexId); snapshotId.getUUID());
} catch (IOException ex) {
logger.warn(() -> new ParameterizedMessage("[{}] failed to delete metadata for index [{}]";
snapshotId; indexId.getName()); ex);
}
}
@Override
