Synonym rule for text was ignored – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch encounters a synonym rule for a text that it cannot process. This could be due to incorrect syntax, a missing synonym file, or a non-existent synonym. To resolve this issue, you can check the syntax of your synonym rules, ensure the synonym file is in the correct location and accessible, or verify that the specified synonym exists. Additionally, you should also check if the analyzer is correctly configured to use the synonym filter.

This guide will help you check for common problems that cause the log ” Synonym rule for [” + text + “] was ignored ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: analysis.

Log Context

Log “Synonym rule for [” + text + “] was ignored” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

    public CharsRef analyze(String text; CharsRefBuilder reuse) throws IOException {
        try {
            return super.analyze(text; reuse);
        } catch (IllegalArgumentException ex) {
            if (lenient) {
      "Synonym rule for [" + text + "] was ignored");
                return new CharsRef("");
            } else {
                throw ex;


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?