@ -168,7 +168,9 @@ class ListenAndServ(object):
'endpoint': self.endpoint,
'Fanin': self.fan_in,
'OptimizeBlock': current_block,
'PrefetchBlock': empty_block
'PrefetchBlock': empty_block,
'sync_mode': True, # did not support async now in layers
'grad_to_block_id': []
})