private void nextWorker(Metrics metrics) {
        nextAlarmWorker.ifPresent(nextAlarmWorker -> nextAlarmWorker.in(metrics));
        nextExportWorker.ifPresent(
            nextExportWorker -> nextExportWorker.in(new ExportEvent(metrics, ExportEvent.EventType.TOTAL)));
    }
Build given prepareRequests to prepare database flush

@param metricsList     the metrics in the last read from the in-memory aggregated cache.
@param prepareRequests the results for final execution.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsPersistentWorker.java