elastic/elasticsearch · error · IllegalArgumentException

keyword filter requires either `keywords`, `keywords_path`,

Error message

keyword filter requires either `keywords`, `keywords_path`, or `keywords_pattern` to be configured

What it means

Error "keyword filter requires either `keywords`, `keywords_path`, or `keywords_pattern` to be configured" thrown in elastic/elasticsearch.

Source

Thrown at modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/KeywordMarkerTokenFilterFactory.java:63

    private final AnalysisMode analysisMode;

    KeywordMarkerTokenFilterFactory(IndexSettings indexSettings, Environment env, String name, Settings settings) {
        super(name);

        boolean ignoreCase = settings.getAsBoolean("ignore_case", false);
        String patternString = settings.get("keywords_pattern");
        if (patternString != null) {
            // a pattern for matching keywords is specified, as opposed to a
            // set of keyword strings to match against
            if (settings.get("keywords") != null || settings.get("keywords_path") != null) {
                throw new IllegalArgumentException("cannot specify both `keywords_pattern` and `keywords` or `keywords_path`");
            }
            keywordPattern = Pattern.compile(patternString);
            keywordLookup = null;
        } else {
            Set<?> rules = Analysis.getWordSet(env, settings, "keywords");
            if (rules == null) {
                throw new IllegalArgumentException(
                    "keyword filter requires either `keywords`, `keywords_path`, " + "or `keywords_pattern` to be configured"
                );
            }
            // a set of keywords (or a path to them) is specified
            keywordLookup = new CharArraySet(rules, ignoreCase);
            keywordPattern = null;
        }
        boolean updateable = settings.getAsBoolean("updateable", false);
        this.analysisMode = updateable ? AnalysisMode.SEARCH_TIME : AnalysisMode.ALL;
    }

    @Override
    public AnalysisMode getAnalysisMode() {
        return this.analysisMode;
    }

    @Override
    public TokenStream create(TokenStream tokenStream) {

View on GitHub (pinned to db6a809a66)

When it happens

Trigger: Thrown at modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/KeywordMarkerTokenFilterFactory.java:63 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of elastic/elasticsearch@db6a809a66 (2026-08-12). Data as JSON: /api/errors/34aee2d38658ee82. Report an issue: GitHub.