Must be an array – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 8.3-8.9

Briefly, this error occurs when Elasticsearch expects an array input but receives a different data type. This could be due to incorrect formatting or data structure in the request. To resolve this, ensure that the input data is in the correct array format. If the error persists, check the Elasticsearch documentation for the specific API you’re using to ensure you’re providing the correct data structure. Also, validate your JSON input for any syntax errors.

This guide will help you check for common problems that cause the log ” [{}] must be an array ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: .

Log Context

Log “[{}] must be an array” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 while (subParser.nextToken() != XContentParser.Token.END_ARRAY) {
 coordinates.add(parseValidDouble(subParser; name));
 return coordinates;
 } else {
 throw new ElasticsearchParseException("[{}] must be an array"; name);
 }  /**