presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/storage/organization/ShardCompactionManager.java/ShardCompactionManager/start
class ShardCompactionManager:    @PostConstruct
    public void start()
    {
        if (!compactionEnabled) {
            return;
        }

        if (!discoveryStarted.getAndSet(true)) {
            startDiscovery();
        }
    }