TCP_NODELAY is a socket property that disables Nagle's algorithm. Nagle's algorithm is basically about buffering requests to a network packet size before sending. This is the classic throughput vs latency tradeoff but only useful when request size is very small. If the intention is to send the request immediately, e.g. in real time systems, then this property should be turned off. Also if requests are usually not very small then there is no benefit of using Nagle's algorithm and thus keeping it off would be better.