presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/metadata/ShardCleaner.java/ShardCleaner/waitJitterTime
class ShardCleaner:    private void waitJitterTime()
    {
        try {
            // jitter to avoid overloading database
            long interval = this.localCleanerInterval.roundTo(SECONDS);
            SECONDS.sleep(ThreadLocalRandom.current().nextLong(1, interval));
        }
        catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }