elastic/elasticsearch · error · IllegalArgumentException

[size] must be greater than 0. Found [{size}] in [{name}]

Error message

[size] must be greater than 0. Found [{size}] in [{name}]

What it means

Thrown by TimeSeriesAggregationBuilder.setSize when size <= 0. The time_series aggregation groups documents into time-series buckets and requires a positive size to bound the number of series tracked. Zero or negative is meaningless for the internal data structures.

Source

Thrown at modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/timeseries/TimeSeriesAggregationBuilder.java:131

    @Override
    public BucketCardinality bucketCardinality() {
        return BucketCardinality.MANY;
    }

    @Override
    public String getType() {
        return NAME;
    }

    @Override
    public boolean isInSortOrderExecutionRequired() {
        return true;
    }

    public TimeSeriesAggregationBuilder setSize(int size) {
        if (size <= 0) {
            throw new IllegalArgumentException("[size] must be greater than 0. Found [" + size + "] in [" + name + "]");
        }
        this.size = size;
        return this;
    }

    public int getSize() {
        return size;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        if (super.equals(o) == false) return false;
        TimeSeriesAggregationBuilder that = (TimeSeriesAggregationBuilder) o;
        return keyed == that.keyed && size == that.size;
    }

View on GitHub (pinned to db6a809a66)

Solutions

1. Set size to a positive integer reflecting the maximum number of time series to track.
2. Validate that any computed size is >= 1 before calling setSize.
3. Default to a reasonable positive value (e.g. the documented default) when input is absent or zero.

Example fix

// before
{"time_series":{"size":0,...}}
// after
{"time_series":{"size":10000,...}}

if (size <= 0) {
  throw new IllegalArgumentException("time_series size must be > 0");
}

When it happens

Trigger: Calling setSize(0) or setSize(-1) on a time_series aggregation. Submitting a REST request with `"size": 0`. Defaulting size from a configuration variable that was initialized to zero.

Common situations: Misconfigured index mapping time_series dimension. Tests or tooling that pass zero as a boundary value. Pipelines that compute size dynamically and hit a zero edge case.

Related errors

• buckets must be greater than 0 for [{name}]
• [${name}] is missing : filters parameter
• [separator] must not be null: [${name}]
• [key] must not be null
• [filter] must not be null

AI-assisted analysis of elastic/elasticsearch@db6a809a66 (2026-08-12). Data as JSON: /api/errors/7981e8e51a8d6633. Report an issue: GitHub.