@Override
        public void onError(List<Metrics> data, Throwable t) {
            log.error(t.getMessage(), t);
        }
Metrics queue processor, merge the received metrics if existing one with same ID(s) and time bucket.

ID is declared through {@link Object#hashCode()} and {@link Object#equals(Object)} as usual.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsPersistentWorker.java