Netty is a production-grade, asynchronous event-driven network application framework written in Java. It is organized as a large multi-module Maven project whose core abstractions are Channel, EventLoop, ChannelHandler pipelines, reference-counted ByteBuf, codec base classes, and pluggable transports. The repository implements an exceptionally broad set of protocol codecs including HTTP/1.x, HTTP/2, HTTP/3, WebSocket, DNS, MQTT, Redis, memcache, SMTP, SOCKS, SPDY, STOMP, HAProxy, compression, and QUIC over BoringSSL. Native transports for epoll, kqueue, and io_uring are built via JNI, and the newer IoHandle/IoOps/IoEvent layer demonstrates ongoing architectural modernization for high-throughput I/O. In practice, applications use Bootstrap or ServerBootstrap to bind/connect channels, compose handlers into pipelines, and manipulate ByteBuf for zero-copy-friendly data handling. The codebase emphasizes performance: pooled buffer allocators, size-class tuning, internal concurrency primitives, JFR events, and JMH microbenchmarks. It also includes extensive integration tests across native transports, JPMS compatibility tests, and native-image metadata. Some legacy transports (UDT, RXTX, OIO) and a handful of APIs are deprecated or marked @UnstableApi, but overall the framework is actively maintained and tracks modern JDK and protocol developments. The project is not a data pipeline or research repository; its benchmarks and tests serve software quality verification rather than analytical output. The dominant character is a reusable application framework/library. Its craftsmanship is exceptional, though the sheer size and native JNI surface mean individual components must be extracted with care.
Netpoll is a high-performance non-blocking I/O networking framework for Go, developed by ByteDance for RPC scenarios. It provides an event-loop server and dialer with zero-copy Reader/Writer APIs backed by a custom linked buffer (LinkBuffer). Under the hood, it uses epoll on Linux and kqueue on BSD, with an operator cache and a load-balanced poll manager. The architecture is a non-blocking reactor pattern: an event loop accepts connections, assigns them to pollers, and schedules OnRequest/OnConnect/OnDisconnect callbacks asynchronously via a goroutine pool. The library features connection health checking, idle timeout, and a connection reuse probe for client pools. It is production-ready and used by ByteDance's RPC framework Kitex and HTTP framework Hertz.