Briefly, this error occurs when Elasticsearch is unable to read metadata from the store, possibly due to corruption or unavailability of the data store. To resolve this issue, you can try the following: 1) Check the health status of your Elasticsearch cluster and ensure all nodes are functioning properly. 2) Verify the integrity of your data store and fix any corruption issues. 3) If the data store is unavailable, ensure it is properly connected and accessible. 4) If the error persists, consider restoring from a backup.
This guide will help you check for common problems that cause the log ” [{}] can’t read metadata from store; responding with empty ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: indices, metadata.
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 “[{}] can’t read metadata from store; responding with empty” classname is TransportNodesListShardStoreMetadata.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
return storeFilesMetadata;
} catch (org.apache.lucene.index.IndexNotFoundException e) {
logger.trace(new ParameterizedMessage("[{}] node is missing index; responding with empty"; shardId); e);
return StoreFilesMetadata.EMPTY;
} catch (IOException e) {
logger.warn(new ParameterizedMessage("[{}] can't read metadata from store; responding with empty"; shardId); e);
return StoreFilesMetadata.EMPTY;
}
}
}
final String customDataPath;
