Briefly, this error occurs when Elasticsearch attempts to parse an attachment and encounters an unexpected data type. The field in question is expected to be a string, but a different data type has been provided. To resolve this issue, you can check the data you’re trying to index to ensure that the field is indeed a string. If it’s not, you should convert it to a string before indexing. Alternatively, you can modify your mapping to accept the data type you’re providing.
This guide will help you check for common problems that cause the log ” could not parse data attachment. expected string value for [{}] field but ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.
Log Context
Log “could not parse data attachment. expected string value for [{}] field but” class name is DataAttachment.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
Field.FORMAT.getPreferredName(); token);
} else if (Field.FORMAT.match(currentFieldName; parser.getDeprecationHandler())) {
if (token == XContentParser.Token.VALUE_STRING) {
dataAttachment = resolve(parser.text());
} else {
throw new ElasticsearchParseException("could not parse data attachment. expected string value for [{}] field but " +
"found [{}] instead"; currentFieldName; token);
}
} else {
throw new ElasticsearchParseException("could not parse data attachment. unexpected field [{}]"; currentFieldName);
}
