is designed for Unix-like platforms, with best performance and scalability on systems supporting epoll (Linux), kqueue (BSD/macOS), or /dev/poll (Solaris). Tornado will also run on Windows, although this /var/log/nginx/error.log; pid /var/run/nginx.pid; events { worker_connections 1024; use epoll; } http { # Enumerate all the Tornado servers here upstream frontends { server 127 choice of implementation is likely to be a global decision (e.g. when epoll [https://docs.python.org/3/library/select.html#select.epoll] is available, always use it instead of select [https://docs.python

{ conn, _ := listener.Accept() epoll_ctl(conn.fd, readable...) } go func() { events := make([]event, 128) for { n, _ := epoll_wait(epoll_fd, events, wait_msec) for i:=0; (sofa-mosn)|evio|go net| |---|---|---|---|---|---| |Epoll(ET/LT)|LT|LT|ET/LT|LT|ET| |NIO|✓|✓|✓|✓|| |ZeroCopy Buffer|✓||||| |Multisyscall|✓||||| ## 搭建 Netpoll func go epoll_wait() epoll_ctl() poller var conns... go func() n, _ := epoll_wait(epoll_fd, events, msec) for i := 0; i < n; i++ { Read() / Write() / Catch(error) } } } ## 搭建 Netpoll func go epoll_wait() epoll_ctl() poller

例如sheepdog的开发者提交过一个patch，但是测试效果不理想，分析原因，event loop依然是瓶颈 ## 对TGT的性能优化 • IO是使用多个epoll线程，充分发挥多CPU能力 - 当前策略是每个target一个epoll线程，负责Initiator发过来的I/O - 好处是各target上的CPU使用由OS负责分配，CPU分配粒度更细 - 也可以多个卷的lun都分配到一个 connection, params都在主线程，而target epoll线程也要使用这些数据，多线程冲突，数据一致性问题就来了 ## 对TGT的性能优化（续） ## • 为每一个target增加一把锁 • Target event loop (TEL) 线程和管理面线程使用这把锁互斥 • TEL在运行时锁住这把锁，管理面只能等待，等TEL线程进入epoll wait状态，会释放这把锁，管理面可以增删改target信息。 tgt_event_loop(struct tgt_evloop *evloop) { int nevent, i, sched_remains, timeout; struct epoll_event events[1024]; struct event_data *tev; } retry: sched_remains = tgt_exec_scheduled(evloop);

fsbase 寄存器保存的地址是否在 kernel current task 的 512GB 地址空间内？ > 若不是，代表当前在RPAL Call， 将 pt_regs 拷贝并覆盖掉之前处于 epoll_wait 上下文的 receiver 线程的内 核栈中  Sender 进程 ## 第四部分 ## 高效的Go Event Poller ## 高效的Go Event Poller Go 原生 epoll 模型 1. writev syscall 2. epoll wait 3. readv syscall 4. 可能还有 futex_wake  ## 高效的Go Event Poller ## 纯用户态 poller 实现 1. writev-syscall 2. epoll—wait 3. readv-syscall 4. 仅在必要时调用 futex_wake （没有自旋线程 && 有 idle P） ![Image](/uploads/doc

## V ersions • Support Netty native epoll on Linux. • Ability to configure arbitrary security role mappings. • AMQP performance improvements Final.jar|io.netty:netty-transport|| |netty-transport-classes-epoll-4.1.82.Final.jar|io.netty:netty-transport-classes-epoll|only if you want epoll on Linux| |netty-transport-classes-kqueue-4.1.82.Final.jar|io want kqueue on MacOS| |netty-transport-native-epoll-4.1.82.Final-linux-x86\_64.jar|io.netty:netty-transport-native-epoll:linux-x86\_64|only if you want epoll on Linux| |netty-transport-native-kqueue-4.1

buffer开销 ◆ Runtime调度开销 ## 技术案例－长连接网关RawEpoll模式 RawEpoll模式：使用epoll感知到可读事件之后，再从协程池中为其分配协程进行处理。大幅减少goroutine实例数量，从而降低内存、调度开销 1. 链接建立后，向epoll注册oneshot 可读事件监听；并且此时不允许有协程调用conn.read，避免与runtime netpoll冲突。 1K 请求/响应 |场景|QPS|MEM(K)|CPU(%)|goroutine| |---|---|---|---|---| |原生IO模式|1000|3.3|60|200028| |Raw Epoll模式|1000|2.5|18|28| ## 持续演进实践总结 ✓ 架构上，从一开始就遵循分层设计，模块解耦，统一编程模型接口，保证足够的架构扩展性。 ✓ 性能上，针对IO、协议、内存、协程进行 0版本QPS提升了50%，内存使用减少了40%；HTTP/2.0相比官方库原生实现，QPS提升了100%；HTTP/1.1也有30%以上的性能提升。同时，针对具体问题提供具体的解决方案，例如对于长连接网关场景，提供raw epoll模式来优化性能表现。 ✓ 能力上，经过多轮演进，0.4.0版本已经初步具备了生产所需的大部分功能点，支持云原生场景下的多协议、路由&LB、后端管理、TLS、遥感监测、XDS对接等功能，并

st> Highlights: • Broker plugin support. • Support Netty native epoll on Linux. • Ability to configure arbitrary security role mappings. • AMQP performance improvements Final.jar|io.netty:netty-transport|| |netty-transport-classes-epoll-4.1.79.Final.jar|io.netty:netty-transport-classes-epoll|only if you want epoll on Linux| |netty-transport-classes-kqueue-4.1.79.Final.jar|io want kqueue on MacOS| |netty-transport-native-epoll-4.1.79.Final-linux-x86\_64.jar|io.netty:netty-transport-native-epoll:linux-x86\_64|only if you want epoll on Linux| |netty-transport-native-kqueue-4.1

#### 2.1. 0 Full release notes. Highlights: • Broker plugin support. • Support Netty native epoll on Linux. • Ability to configure arbitrary security role mappings. • AMQP performance improvements Final.jar|io.netty:netty-transport|| |netty-transport-classes-epoll-4.1.79.Final.jar|io.netty:netty-transport-classes-epoll|only if you want epoll on Linux| |netty-transport-classes-kqueue-4.1.79.Final.jar|io want kqueue on MacOS| |netty-transport-native-epoll-4.1.79.Final-linux-x86\_64.jar|io.netty:netty-transport-native-epoll:linux-x86\_64|only if you want epoll on Linux| |netty-transport-native-kqueue-4.1

#### 2.1. 0 Full release notes. Highlights: • Broker plugin support. • Support Netty native epoll on Linux. • Ability to configure arbitrary security role mappings. • AMQP performance improvements Final.jar|io.netty:netty-transport|| |netty-transport-classes-epoll-4.1.93.Final.jar|io.netty:netty-transport-classes-epoll|only if you want epoll on Linux| |netty-transport-classes-kqueue-4.1.93.Final.jar|io want kqueue on MacOS| |netty-transport-native-epoll-4.1.93.Final-linux-x86\_64.jar|io.netty:netty-transport-native-epoll:linux-x86\_64|only if you want epoll on Linux| |netty-transport-native-kqueue-4.1

#### 2.1. 0 Full release notes. Highlights: • Broker plugin support. • Support Netty native epoll on Linux. • Ability to configure arbitrary security role mappings. • AMQP performance improvements Final.jar|io.netty:netty-transport|| |netty-transport-classes-epoll-4.1.86.Final.jar|io.netty:netty-transport-classes-epoll|only if you want epoll on Linux| |netty-transport-classes-kqueue-4.1.86.Final.jar|io want kqueue on MacOS| |netty-transport-native-epoll-4.1.86.Final-linux-x86\_64.jar|io.netty:netty-transport-native-epoll:linux-x86\_64|only if you want epoll on Linux| |netty-transport-native-kqueue-4.1