redis/jedis · error · IllegalArgumentException

Aggregators must be non-null and non-empty

Error message

Aggregators must be non-null and non-empty

What it means

TSMRangeParams.aggregation(AggregationType[] aggregators, long bucketDuration) validates that when a non-null aggregators array is supplied it is non-empty and contains no null elements, since TS.RANGE/TS.MSEARCH aggregation requires at least one concrete aggregator. An empty array throws IllegalArgumentException("Aggregators must be non-null and non-empty").

Solutions

1. Pass at least one AggregationType, e.g. aggregation(new AggregationType[]{AggregationType.AVG}, 60000).
2. Guard the call site: if the aggregator list is empty, skip setting aggregation instead of passing an empty array.
3. Validate user/config input to ensure at least one aggregation is selected when aggregation is intended.

Example fix

// before
params.aggregation(aggList.toArray(new AggregationType[0]), 60000); // throws when empty
// after
if (!aggList.isEmpty()) {
  params.aggregation(aggList.toArray(new AggregationType[0]), 60000);
}

if (aggregators != null && aggregators.length == 0) {
  throw new IllegalArgumentException("Provide at least one AggregationType");
}
params.aggregation(aggregators, bucketDuration);

boolean hasAggregators(AggregationType[] a) {
  return a != null && a.length > 0;
}

try {
  params.aggregation(aggs, bucketMs);
} catch (IllegalArgumentException e) {
  params = new TSMRangeParams(from, to); // proceed without aggregation
  log.warn("Aggregation skipped: {}", e.getMessage());
}

When it happens

Trigger: Calling aggregation(new AggregationType[0], bucketDuration) or passing an empty array produced from an empty list/collection (e.g. aggregation(aggregatorList.toArray(new AggregationType[0]), 60000) with an empty list).

Common situations: Building range queries from user-selected aggregations where none were selected; config-driven dashboards where the aggregation list defaults to empty; refactors replacing the single AggregationType overload with the array overload but passing an empty array.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• Aggregators must not contain null elements
• FILTER arguments must be set.
• EXCLUDEEMPTY is not allowed with GROUPBY.
• Aggregators must be non-null and non-empty
• Aggregators must not contain null elements

AI-assisted analysis of redis/jedis@6dac31d4c2 (2026-09-08). Data as JSON: /api/errors/e98b762ce14c8b52. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/redis/clients/jedis/timeseries/TSMRangeParams.java:158

      this.bucketDuration = 0;
    }
    return this;
  }

  /**
   * Specifies multiple aggregators to be applied in a single {@code TS.MRANGE} / {@code TS.MREVRANGE} call. Aggregators are
   * sent on the wire in the given order and the response values appear in the same order in {@link TSElement#getValues()}.
   * Single-element arrays are accepted and behave like {@link #aggregation(AggregationType, long)}.
   *
   * @param aggregators ordered, non-empty list of aggregators
   * @param bucketDuration aggregation bucket duration in milliseconds
   * @return this
   * @throws IllegalArgumentException if {@code aggregators} is empty
   */
  public TSMRangeParams aggregation(AggregationType[] aggregators, long bucketDuration) {
    if (aggregators != null) {
      if (aggregators.length == 0) {
        throw new IllegalArgumentException("Aggregators must be non-null and non-empty");
      }
      for (AggregationType a : aggregators) {
        if (a == null) {
          throw new IllegalArgumentException("Aggregators must not contain null elements");
        }
      }
      this.aggregators = aggregators;
      this.bucketDuration = bucketDuration;
    } else {
      this.aggregators = null;
      this.bucketDuration = 0;
    }
    return this;
  }

  /**
   * This requires AGGREGATION.
   */

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