I am working on a high-performance TCP server that maintains persistent SSL over TCP connections with clients. And, the clients send application messages of sizes varying from 0.8MB to 4MB in custom binary format. To read these payloads, I am using ReplayingDecoder interface in Netty with checkpoint states. However, I am seeing that the amount of bytes I am able to read as part of each call to decode() is always capped at 10240 bytes. I even tried changing the RCVBUF_ALLOCATOR with a higher window size but still doesnt help. I am using Epoll to read data into the application. Can Netty experts chime in and let me know where this magical 10240 bytes (10KB) is coming from? And, how can I increase this limit to improve my overall TCP network throughput?
.childOption(ChannelOption.RCVBUF_ALLOCATOR, new FixedRecvByteBufAllocator(64 * 1024))