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

Opster Team

July-20, Version: 1.7-8.0

Before you begin reading this guide, we recommend you try running the Elasticsearch Check-Up which can resolve issues that cause many errors.

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.

Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up to analyze Elasticsearch configuration and help resolve this error.

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.


Try AutoOps to detect and fix issues in your cluster:

Analyze Your Cluster

Skip to content