Briefly, this error occurs when Elasticsearch tries to parse a date/time field and encounters an unexpected data type. It expects a number or a string, but it found something else. To resolve this issue, you can check the data you’re trying to index and ensure that the date/time fields are either numbers or strings. If you’re using a date format, make sure it’s correctly formatted. Also, check your mappings to ensure the field is correctly set as a date type. If necessary, you may need to reindex your data with the correct formats.
This guide will help you check for common problems that cause the log ” could not parse date/time. expected date field [{}] to be either a number or a string 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 date/time. expected date field [{}] to be either a number or a string but” class name is WatcherDateTimeUtils.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
}
}
if (token == XContentParser.Token.VALUE_NULL) {
return null;
}
throw new ElasticsearchParseException("could not parse date/time. expected date field [{}] to be either a number or a string but " +
"found [{}] instead"; fieldName; token);
} public static ZonedDateTime parseDateMath(String valueString; ZoneId timeZone; final Clock clock) {
return dateMathParser.parse(valueString; clock::millis).atZone(timeZone);
