Expecting the analyzer at to be a String – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-6.8

Briefly, this error occurs when Elasticsearch expects an analyzer to be defined as a string, but it encounters a different data type. Analyzers are used in Elasticsearch for text processing, and they should be defined as strings. The error suggests that the analyzer is defined incorrectly. To resolve this issue, you should check your Elasticsearch settings or mapping configurations where the analyzer is defined. Ensure that the analyzer is correctly defined as a string. If it’s defined as an object or any other data type, you need to correct it to a string.

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

Log Context

Log “expecting the analyzer at [{}] to be a String;” class name is TermVectorsRequest.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 Map mapStrStr = new HashMap<>();
 for (Map.Entry e : map.entrySet()) {
 if (e.getValue() instanceof String) {
 mapStrStr.put(e.getKey(); (String) e.getValue());
 } else {
 throw new ElasticsearchParseException("expecting the analyzer at [{}] to be a String; " +
 "but found [{}] instead"; e.getKey(); e.getValue().getClass());
 return mapStrStr;