apache/skywalking · error · IllegalArgumentException

Incompatible BucketedValues [{}] for current HistogramFuncti

Error message

Incompatible BucketedValues [{}] for current HistogramFunction[{}]

What it means

AvgHistogramFunction (avgHistogram in MAL) keeps summation and count DataTables keyed by bucket name and averages them at calculation time. accept() enforces the same compatibility rule as HistogramFunction: once the dataset is non-empty, incoming BucketedValues must carry the identical bucket key set or the accept is rejected.

Source

Thrown at oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/meter/function/avg/AvgHistogramFunction.java:90

    @BanyanDB.MeasureField
    protected DataTable summation = new DataTable(30);
    @Getter
    @Setter
    @Column(name = COUNT, storageOnly = true)
    @ElasticSearch.Column(legacyName = "count")
    @BanyanDB.MeasureField
    protected DataTable count = new DataTable(30);
    @Getter
    @Setter
    @Column(name = DATASET, dataType = Column.ValueDataType.HISTOGRAM, storageOnly = true, defaultValue = 0)
    @BanyanDB.MeasureField
    private DataTable dataset = new DataTable(30);

    @Override
    public void accept(final MeterEntity entity, final BucketedValues value) {
        if (dataset.size() > 0) {
            if (!value.isCompatible(dataset)) {
                throw new IllegalArgumentException(
                    "Incompatible BucketedValues [" + value + "] for current HistogramFunction[" + dataset + "]");
            }
        }

        this.entityId = entity.id();

        final long[] values = value.getValues();
        for (int i = 0; i < values.length; i++) {
            long bucket = value.getBuckets()[i];
            String bucketName = bucket == Long.MIN_VALUE ? Bucket.INFINITE_NEGATIVE : String.valueOf(bucket);
            summation.valueAccumulation(bucketName, values[i]);
            count.valueAccumulation(bucketName, 1L);
        }
    }

    @Override
    public boolean combine(final Metrics metrics) {
        AvgHistogramFunction histogram = (AvgHistogramFunction) metrics;

View on GitHub (pinned to 102af09b4a)

Solutions

Pin one bucket definition per metric name and configure all producers (agents, collectors, MAL rules) to use it
Introduce a versioned metric name (e.g. _v2) when bucket boundaries must change, keeping datasets homogeneous
Restart OAP to clear in-memory datasets after fixing the producer config; drop the old persisted model if it holds incompatible keys

Example fix

# before
service_latency_percentile:
  exp: otel...duration.bucket({'10','50','100'})
  meterFunction: avgHistogram
# another producer sends buckets {'20','80'} for the same metric

# after — single bucket set for the metric name across all producers
service_latency_percentile:
  exp: otel...duration.bucket({'10','50','100'})
  meterFunction: avgHistogram

Defensive patterns

Strategy: try-catch

Validate before calling

// before emitting an avgHistogram metric, verify the bucket set matches the metric's contract
if (!Arrays.equals(buckets, expectedBucketsForMetric.get(metricName))) {
    log.warn("Ignoring {} with foreign bucket set {}", metricName, Arrays.toString(buckets));
    return;
}

Try / catch

try {
    avgHistogramMetric.accept(entity, bucketedValues);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("Incompatible BucketedValues")) {
        log.error("Bucket drift on avgHistogram metric {}", metricName, e);
        return;
    }
    throw e;
}

Prevention

Pin a single valueBuckets list per avgHistogram metric name across agents and rules
Standardize agent default buckets fleet-wide before metrics go live
Version metric names when bucket boundaries must evolve

When it happens

Trigger: An avgHistogram MAL metric is fed BucketedValues whose bucket boundaries differ from those already accumulated — different agent bucket defaults for one metric name, edited valueBuckets in the rule, or the infinity-negative sentinel bucket (Long.MIN_VALUE -> 'InfiniteNegative' key) present in one stream and absent in another.

Common situations: Mixed agent versions reporting the same avgHistogram metric; per-service bucket overrides; OTel collector exporters translating explicit-bucket histograms with changed boundaries.

Related errors

AI-assisted analysis of apache/skywalking@102af09b4a (2026-08-14). Data as JSON: /api/errors/c22c50f431335212. Report an issue: GitHub.