should be a hash but was of type: – How to solve this Elasticsearch error

Opster Team

July-20, Version: 1.7-8.0

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This guide will help you check for common problems that cause the log ” should be a hash but was of type: ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: Node.

Log Context

Log “should be a hash but was of type:”classname  is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

public static Map nodeMapValue(Object node; String desc) {
 if (node instanceof Map) {
 return (Map) node;
 } else {
 throw new ElasticsearchParseException(desc + " should be a hash but was of type: " + node.getClass());
 * Returns an array of string value from a node value.


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