in a computer network environment , a server protocol is provided to process read requests from clients . rather than all read requests being processed synchronously or all read requests being processed asynchronously , an attempt is first made to perform a synchronous read . if the synchronous read is unsuccessful , the connection through which the request was received by the server is registered with a monitoring service . when the data is ready to be read , an appropriate callback is called and the data transmitted . an optional delay may be imposed before the synchronous read is attempted to increase the likelihood that the attempt will be successful . a series of delays / read attempts may also be employed in order to increase the likelihood still further that an attempt will be successful .