Seastar is a high-performance C++ asynchronous framework built on a shared-nothing, reactor-based architecture. It provides core primitives like futures/promises, coroutine support, per-CPU sharding, and a sophisticated I/O scheduler with fair queuing and token-bucket throttling. The framework includes a production-grade networking stack (TCP, UDP, TLS, HTTP, WebSocket, RPC), a custom memory allocator, comprehensive metrics (Prometheus, collectd), and extensive testing/benchmarking infrastructure. Seastar is used by real-world systems such as ScyllaDB, Redpanda, and Ceph Crimson. The codebase is mature, but exhibits some technical debt in the form of deprecated API usage, platform-specific workarounds, and a few license inconsistencies. Overall, it represents a strong example of systems-level C++ engineering with reusable algorithmic components and a well-documented architecture.
Pktgen is a high-performance, scriptable packet generator built on top of DPDK. It generates wire-rate traffic with support for Ethernet, IPv4/IPv6, TCP/UDP, GRE, GTP-U, MPLS, VLAN, and other encapsulations. The application provides an interactive CLI with auto-complete, history, and environment variables, as well as Lua scripting for automation. It includes features like latency measurement, packet capture/replay, range-based packet field sweeping, random bitfield generation, and RFC 2544 throughput testing. The architecture is a monolithic DPDK application with modular libraries for CLI, Lua bindings, hash maps, vectors, plugins, and common utilities. It is designed for network testing, benchmarking, and research scenarios requiring precise traffic generation and measurement.
Netis Cloud Probe is a production-grade network packet capture and forwarding system designed to monitor traffic without requiring dedicated TAP or SPAN hardware. It consists of a high-performance C capture engine (cpworker), a Go daemon (cpdaemon) that manages worker processes and communicates with a central policy manager (CPM), and a Go CLI (cpctl) for manual control. The system supports multiple capture sources (libpcap, DPDK, pcap files) and output sinks (GRE, VXLAN, ZMQ, rotating files) with a configurable execution model (real-time or pipelined using a lock-free SPSC ring buffer). Configuration reload is handled via a state-machine protocol, enabling hot-swapping of tasks without packet loss. The codebase is multi-language (C, Go) with CMake and Mage build systems, comprehensive unit and integration tests, and bilingual documentation (English, Chinese). It is actively maintained with a recent commit and continuous integration.