Regexp queries cannot be executed when – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 7.7-7.15

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Briefly, this error occurs when ‘script.painless.regex.enabled’ setting is set to false in Elasticsearch. This setting controls the execution of regular expression in Painless scripts. If it’s disabled, you cannot execute [regexp] queries. To resolve this issue, you can enable this setting by updating the Elasticsearch configuration file (elasticsearch.yml) or using the cluster settings API to set ‘script.painless.regex.enabled’ to true. However, be aware that enabling this setting might have performance implications as regular expressions can be expensive to execute.

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This guide will help you check for common problems that cause the log ” [regexp] queries cannot be executed when ‘ ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: index.

Log Context

Log “[regexp] queries cannot be executed when ‘” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 public Query regexpQuery(String value; int syntaxFlags; int matchFlags; int maxDeterminizedStates;
 MultiTermQuery.RewriteMethod method; SearchExecutionContext context) {
 if (context.allowExpensiveQueries() == false) {
 throw new ElasticsearchException("[regexp] queries cannot be executed when '" +
 ALLOW_EXPENSIVE_QUERIES.getKey() + "' is set to false.");
 RegexpQuery query = new RegexpQuery(new Term(name(); indexedValueForSearch(value)); syntaxFlags;
 matchFlags; maxDeterminizedStates);


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