Like the batching of messages with producers, Kafka batches messages for consumers to achieve higher throughput.
socket.receive.buffer.size: The size of the socket receive buffer. The default is 100KB or 102400 bytes which might not be sufficient if you have a higher volume of data to be published and read. You can consider increasing this to 8MB or 16MB if you have high-bandwidth networks and enough memory. If not, you can go down to 1MB.
fetch.min.bytes: This parameter sets the minimum number of bytes expected for a fetch response from a consumer. Increasing this will reduce the number of fetch requests made to the broker, reducing the broker CPU overhead to process each fetch.