### LEARNING socket.io Free unaffiliated eBook created from Stack Overflow contributors. ## Table of Contents About ..... 1 Chapter 1: Getting started with socket.io ..... 2 Remarks ..... 2 Versions Versions ..... 2 Examples ..... 3 Installation or Setup ..... 3 "Hello world!" with socket messages ..... 4 Chapter 2: Broadcast ..... 6 Examples ..... 6 Broadcasting to all users .. Fire Events ..... 7 Examples ..... 7 Fire Custom Events ..... 7 Chapter 4: Handling users with socket.io ..... 8 Introduction ..... 8 Examples ..... 8 Example Server Side code for handling Users

## Steering connections to sockets with BPF socket lookup hook Jakub Sitnicki, Cloudflare @jkbs0 @cloudflare eBPF Summit ## Who am I? - Software Engineer at Cloudflare Spectrum TCP/UDP reverse proxy seconds scan first 1000 ports 7, 77, 777 are closed ## What is socket lookup? Application Receive path for local delivery  Protocol ## Driver ## Service dispatch with BPF socket lookup packet metadata struct bpf_sk_lookup { __u32 family; __u32 protocol; __u32 remote_ip4; __u32

• waitress-serve • Socket Activation Glossary ## Change History #### 3. 0.1 (unreleased) - Fix a bug that would lead to Waitress busy looping on select() on a half-open socket due to a race condition "main" - Fix a bug that would appear on macOS whereby if we accept() a socket that is already gone, setting socket options would fail and take down the server. See https://github.com/Pylons/waitress/pull/399 length checking had a calculation that was done incorrectly when the data was received across multiple socket reads. This calculation has been corrected, and no longer will Waitress send back a 413 Request Entity

UNIX domain socket (to serve a downstream HTTP server/proxy such as nginx, lighttpd, and so on), call serve with the unix_socket argument: from waitress import serve serve(wsgiapp, unix_socket='/path/to/unix PasteDeploy syntax for UNIX domain sockets is analogous: [server:main] use = egg:waitress#main unix_socket = /path/to/unix.sock You can find more settings to tweak (arguments to waitress.serve or equivalent file_wrapper protocol. ### 1.6 waitress API serve (app, listen='0.0.0.0:8080', unix_socket=None, unix_socket_perms='600', threads=4, url_scheme='http', url_prefix='', ident='waitress'

# Gevent-socketio documentation ## I ntroduction Socket.IO is a WebSocket-like abstraction that enables real-time communication between a browser and a server. gevent-socketio is a Python implementation implementation of the protocol. The reference server implementation of Socket.IO runs on Node.js and was developed by LearnBoost. There are now server implementations in a variety of languages. One aim of this gevent python WSGI server to use gevent-socketio. Namespaces: since you mostly have one websocket/socket.io endpoint per website, it is important to be able to namespace the different real-time activities

Examples 7 5 Security 9 6 API docs 11 7 References 13 8 Contacts 15 9 Credits 17 10 TODO 19 Socket.IO is a WebSocket-like abstraction that enables real-time communication between a browser and a server gevent-socketio is a Python implementation of the protocol. The reference server implementation of Socket.IO runs on Node.js and was developed by LearnBoost. There are now server implementations in a variety gevent python WSGI server to use gevent-socketio. Namespaces: since you mostly have one websocket/socket.io endpoint per website, it is important to be able to namespace the different real-time activities

## 67 -328 Building Distributed Applications WebSockets ### HTTP / AJAX / WebSockets / Socket.io • Recall that HTTP is request/response protocol • AJAX allows you to do HTTP request/response within message • And send messages to the client ### Socket.io • Library for full-duplex communication between clients and servers - Built on engine.io, socket.io provides an abstraction above whatever transport transport methods are available in the browser: – WebSockets — Long Polling ### Socket.io • Also provides a simple abstraction for event-based programming across the server and multiple clients • Clients

waitress API • Arguments to waitress.serve • Support for wsgi.file wrapper • waitress-serve • Socket Activation Glossary ## Change History #### 1.4. 0 (2019-12-20) ## Bugfixes - Waitress used to slam apply backpressure on the app_iter to avoid letting it spin faster than data can be written to the socket. This stabilizes responses that iterate quickly with a lot of data. See https://github.com/Pylons/waitress/pull/242 com/Pylons/waitress/pull/242 - Stop early and close the app_iter when attempting to write to a closed socket due to a client disconnect. This should notify a long-lived streaming response when a client hangs up

waitress API • Arguments to waitress.serve • Support for wsgifile wrapper • waitress-serve • Socket Activation Glossary ## Change History #### 2.1.1 ## Security Bugfix - Waitress now validates that OError is no longer subscriptable, this caused failures on Windows attempting to loop to find an socket that would work for use in the trigger. See https://github.com/Pylons/waitress/pull/361 - Fixed the WSGI app starts sending data to the output buffer, we now attempt to send data directly to the socket. This avoids needing to wake up the main thread. to start sending data. Allowing faster transmission

waitress API • Arguments to waitress.serve • Support for wsgi.file wrapper • waitress-serve • Socket Activation Glossary ## Change History #### 2.1. 0 ## Python Version Support • Python 3.6 is no longer OError is no longer subscriptable, this caused failures on Windows attempting to loop to find an socket that would work for use in the trigger. See https://github.com/Pylons/waitress/pull/361 - Fixed the WSGI app starts sending data to the output buffer, we now attempt to send data directly to the socket. This avoids needing to wake up the main thread to start sending data. Allowing faster transmission