presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/metadata/ShardCleaner.java/ShardCleaner/runLocalCleanup
class ShardCleaner:    private synchronized void runLocalCleanup()
    {
        try {
            cleanLocalShards();
        }
        catch (Throwable t) {
            log.error(t, "Error cleaning local shards");
            localJobErrors.update(1);
        }
    }