Unknown parameter boost on mapper ” + name + ” – How to solve this Elasticsearch error

Opster Team

March-22, Version: 1.7-8.0

Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which analyzes 2 JSON files to detect many configuration errors.

Briefly, this error indicates that the Elasticsearch mapper name has an unknown parameter “boost”. Boost is a parameter that allows the user to adjust the relevance score of a search query based on the specific field’s importance. The most likely cause of this error is a typo in the mapper name or the use of an incompatible Elasticsearch version. To resolve this error, check the Elasticsearch version and make sure the mapper name is spelled correctly and does not contain an unsupported parameter like “boost”.

To easily locate the root cause and resolve this issue try AutoOps for Elasticsearch & OpenSearch. It diagnoses problems by analyzing hundreds of metrics collected by a lightweight agent and offers guidance for resolving them.

This guide will help you check for common problems that cause the log ” Unknown parameter boost on mapper ” + name + ” ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: index.

Log Context

Log “Unknown parameter [boost] on mapper [” + name + “]”classname  is FieldMapper.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 } else {
 throw new MapperParsingException("Unknown parameter [boost] on mapper [" + name + "]");
 Parameter parameter = deprecatedParamsMap.get(propName);
 if (parameter != null) {


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