question: @ RpcMethod public void startImageScan ( String dataStore , Long scanRate , Long timeout , AsyncMethodCallback < Host . AsyncClient . start_image_scan_call > handler ) throws RpcException { ensureClient ( ) ; StartImageScanRequest request = new StartImageScanRequest ( dataStore ) ; if ( null != scanRate ) { request . setScan_rate ( scanRate ) ; } if ( null != timeout ) { request . setTimeout ( timeout ) ; } try { logger . info ( "start_image_scan target {}, request {}" , getHostIp ( ) , request ) ; clientProxy . setTimeout ( START_IMAGE_SCAN_TIMEOUT_MS ) ; clientProxy . start_image_scan ( request , handler ) ; } catch ( TException e ) { throw new RpcException ( e . getMessage ( ) ) ; } }
target:  This method performs an asynchronous Thrift call to start an image scan on a datastore.