elastic/elasticsearch · error · IllegalArgumentException

[format] must not be null or an empty string.

Error message

[format] must not be null or an empty string.

What it means

Error "[format] must not be null or an empty string." thrown in elastic/elasticsearch.

Source

Thrown at modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilder.java:109

        shift = in.readInt();
    }

    @Override
    protected void doWriteTo(StreamOutput out) throws IOException {
        out.writeString(bucketsPathString);
        script.writeTo(out);
        out.writeOptionalString(format);
        gapPolicy.writeTo(out);
        out.writeInt(window);
        out.writeInt(shift);
    }

    /**
     * Sets the format to use on the output of this aggregation.
     */
    public MovFnPipelineAggregationBuilder format(String format) {
        if (Strings.isNullOrEmpty(format)) {
            throw new IllegalArgumentException("[" + FORMAT.getPreferredName() + "] must not be null or an empty string.");
        }
        this.format = format;
        return this;
    }

    /**
     * Gets the format to use on the output of this aggregation.
     */
    public String format() {
        return format;
    }

    protected DocValueFormat formatter() {
        if (format != null) {
            return new DocValueFormat.Decimal(format);
        }
        return DocValueFormat.RAW;
    }

View on GitHub (pinned to db6a809a66)

When it happens

Trigger: Thrown at modules/aggregations/src/main/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilder.java:109 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/7dd87adf9bea8b40. Report an issue: GitHub.