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 “failed to parse transient metadata for role [{}]. expected {} but got {}” class name is RoleDescriptor.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
if (token == XContentParser.Token.START_OBJECT) {
while (parser.nextToken() != XContentParser.Token.END_OBJECT) {
// it is transient metadata; skip it
}
} else {
throw new ElasticsearchParseException("failed to parse transient metadata for role [{}]. expected {} but got {}" +
" in \"{}\"".""; roleName; XContentParser.Token.START_OBJECT; token; Fields.TRANSIENT_METADATA);
