Analyzer must be set for field name but wasn t – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Before you dig into reading this guide, have you tried asking OpsGPT what this log means? You’ll receive a customized analysis of your log.

Try OpsGPT now for step-by-step guidance and tailored insights into your Elasticsearch operation.

Briefly, this error occurs when a field in Elasticsearch is missing an analyzer. An analyzer is crucial as it is used to convert data into searchable terms. To resolve this issue, you can set an analyzer for the field by updating the mapping of the index. Alternatively, you can specify an analyzer while querying. If you want to use the same analyzer for all fields, you can set a default analyzer in the index settings.

For a complete solution to your to your search operation, try for free AutoOps for Elasticsearch & OpenSearch . With AutoOps and Opster’s proactive support, you don’t have to worry about your search operation – we take charge of it. Get improved performance & stability with less hardware.

This guide will help you check for common problems that cause the log ” Analyzer must be set for field [” + name + “] but wasn’t. ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: index.

Log Context

Log “Analyzer must be set for field [” + name + “] but wasn’t.” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 }  @Override
 public TokenCountFieldMapper build(MapperBuilderContext context) {
 if (analyzer.getValue() == null) {
 throw new MapperParsingException("Analyzer must be set for field [" + name + "] but wasn't.");
 MappedFieldType ft = new TokenCountFieldType(


How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Get expert answers on Elasticsearch/OpenSearch