Adding presentation and initial theme imports

jun.10.2011-doitlive/slides.md

@@ -0,0 +1,287 @@
+![python](python.png)
+Introduction to Redis, Socket.io, Gevent and Django
+###################################################
+
+    Presented by: Thomas Holloway
+
+    Hosted by Nextown Technologies
+    235 Lincoln Road, Miami Beach, FL
+
+---
+
+Do it live!
+===========
+
+<iframe width="750" height="550" src="http://www.youtube.com/embed/5j2YDq6FkVE" frameborder="0" allowfullscreen></iframe>
+
+---
+
+Why sites should be live?
+========================
+
+.notes: More like a game, users will ultimately spend more time on the website as new stuff comes in (A.D.D. awesome!)
+
+* Quicker feedback
+* More informed users
+* More engaging experience
+* More return on investment
+* It's fun development!
+
+
+---
+
+Issues to run into
+==================
+
+* The web is stateless (typically)
+* Managing sessions
+* Connection timeouts
+* Concurrency (**yay!**)
+* Persistence
+* Things can come out of order
+* People do run older browsers (thx IE, thx)
+* Mo' queries, mo' problems
+
+
+---
+
+Messaging patterns
+=========================
+
+**Note: We've always had client/server technologies that can communicate
+in this fashion. Leveraging this on the web is fairly similar.**
+
+* Request-reply: ``connects a set of clients to a set of services. - rpc, task distribution pattern``
+* Publish/Subscribe: ``connects a set of publishers to a set of subscribers. - data distribution pattern.``
+* Push-pull: ``connects nodes in a fan-out / fan-in pattern that can have multiple steps and loops - parallel task distribution, collection pattern.``
+* Exclusive pair: ``connects two sockets in an exclusive pair. - low-level pattern for specific use.``
+
+
+---
+
+<iframe style="margin-top: -130px; margin-left: 40px;" src="http://www.slideshare.net/slideshow/embed_code/2563177" 
+width="725" height="655" frameborder="0" marginwidth="0" marginheight="0" scrolling="no"></iframe>
+
+
+---
+
+Redis.io
+========
+
+Described as: ``an open source, advanced key-value store. Often referred
+to as a data structure server since keys can contain strings, hashes,
+lists, sets and sorted sets.``
+
+Data Structures:
+http://redis.io/topics/data-types
+
+---
+
+Redis.io String Data Structure
+==============================
+- **Strings**: most basic, binary safe, max 512 MB in length
+  - Use strings as atomic counters: INCR, DECR, INCRBY
+  - Append to strings with APPEND
+  - Use strings to access vectors with GETRANGE, SETRANGE
+  - Encode a lot of data in little space, or create a Redis backed Bloom
+    Filter (GETBIT and SETBIT)
+    - http://en.wikipedia.org/wiki/Bloom_filter
+
+---
+
+Redis.io Hashes
+===============
+
+.notes: (few 100, store millions of objects in small instance, 2^(32-1) field-value pairs)
+
+* **Hashes**: maps between string field and string value
+    * Perfect data type to represent objects
+        * Ex: users with a number of fields like name, surname..etc
+
+
+---
+
+Commands for Redis.io Hashes
+============================
+* HDEL ``key field``: delete a hash field
+* HEXISTS ``key field``: does it exist?
+* HGET ``key field``: get a value of a hash field
+* HGETALL ``key``: get all the field and values of a hash
+* HINCRBY ``key field increment``: increment integer value of hash field by given number
+* HKEYS ``key``: get all the fields of a hash
+* HLEN ``key``: number of fields
+* HMGET ``key field [field ...]``: get values of all given hash fields
+* HMSET ``key field value [field value ...]``: set multiple hash-field values
+* HMSETNX ``key field value``: set value of a hash field (only if !exists)
+* HVALS ``key``: get all the values
+
+
+---
+
+![redis](redis.png)
+========
+
+<iframe src="http://try.redis-db.com/" width="860" height="580"
+frameborder="0" marginwidth="0" marginheight="0" scrolling="no"></iframe>
+
+---
+
+Publish/Subscribe with Redis
+============================
+
+    !python
+    from redis import Redis
+    from gevent.greenlet import Greenlet
+    from django.http import HttpResponse
+
+    def listener(socketio):
+        red = Redis('localhost')
+        pubsub = red.pubsub()
+        pubsub.subscribe('users-online')
+        for i in pubsub.listen():
+            socketio.send({'message': i})
+
+    def socketio(request):
+        socketio = request.environ['socketio']
+        while True:
+            message = socketio.recv()
+            if len(message) and message[0] == 'subscribe-me!':
+                g = Greenlet.spawn(listener, socketio)
+
+        return HttpResponse()
+
+    def send_message(json_data):
+        red = Redis('localhost')
+        red.publish('users-online', json_data)
+
+---
+
+Greenlets & GEvent
+==================
+
+gevent is a Python networking library that uses **greenlet** to provide an
+async API on top of **libevent** event loop.
+
+- Fast event loop based on libevent (epoll on Linux, kqueue on FreeBSD)
+- Lightweight execution units based on greenlet
+- Cooperative socket and ssl modules
+- Ability to use standard library and 3rd party modules written for
+  standard blocking sockets (gevent.monkey)
+- DNS queries performed through libevent-dns
+- Fast WSGI server based on libevent-http
+
+**libevent**: API that provides a mechanism to execute a callback function
+when a specific event occurs on a file descriptor or after a timeout has
+been reached. Supports callbacks due to signals or regular timeouts. Meant
+to replace the event loop found in event-driven network servers.
+
+
+---
+
+Web sockets!!
+====================================
+
+.notes: remember how excited you were when you heard about websockets?
+
+![koolaid](koolaid.jpg)
+
+- Case in point... shit breaks for people who don't have it supported
+
+
+---
+
+Socket.io
+=========
+
+.notes: awesome callback support for heartbeats, progressive retries..etc
+
+* Supports cross-domain connections (on every browser)
+* In order to support real-time connectivity on every browser, socket.io
+  selects the most capable transport at runtime.
+    * WebSocket
+    * Adobe Flash Socket
+    * AJAX long polling
+    * AJAX multipart streaming
+    * Forever Iframe
+    * JSONP Polling
+
+---
+
+Socket.io Browsers
+==================
+* Supported browsers
+    * IE 5.5+
+    * Safari 3+
+    * Google Chrome 4+
+    * Firefox 3+
+    * Opera 10.61
+    * **Mobile**: IPhone Safari, IPad Safari, Android WebKit, WebOs WebKit
+
+
+---
+
+Socket.io WSGI Server
+=====================
+
+
+    !python
+    #!/usr/bin/env python
+    # -*- coding: utf-8 -*-
+
+    # Be sure to pip install redis, gevent, gevent-websocket, gevent-socketio
+    from gevent import monkey
+    from socketio import SocketIOServer
+    import django.core.handlers.wsgi
+    import os, sys, settings
+
+    # use gevent to patch the standard lib to get async support
+    monkey.patch_all()
+
+    os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'
+    app = django.core.handlers.wsgi.WSGIHandler()
+    sys.path.insert(0, os.path.join(settings.PROJECT_PATH, '../'))
+    sys.path.insert(0, os.path.join(settings.PROJECT_PATH, 'apps'))
+
+    if __name__ == '__main__':
+        SocketIOServer(('', 7777), app, resource='socket.io').server_forever()
+
+---
+
+Socket.io Javascript
+====================
+
+    !html
+    <script type="text/javascript" src="{{ MEDIA_URL }}js/socket.io.min.js"></script>
+    <script type="text/javascript">
+        $(document).ready(function() {
+            var server = new io.Socket('{{ HOST }}', {{ PORT }});
+            server.on('connect', function() {
+                console.log('Connected to socket.io!!');
+            });
+            server.connect();
+        });
+    </script>
+
+---
+
+Socket.io Events
+================
+
+* connect: fired when the connection is established and the handshake successful.
+* connecting(``transport_type``): fired with a connection is attempted, passing the transport name.
+* connect_failed: Fired when the connection timeout occurs after the last
+* message(``message``): fired when a message arrives
+* close: fired when the connection is closed. Be careful with using this events, as some transports will fire it even under temp, expected disconnections (such as XHR-Polling).
+* disconnect: fired when the connection is considered disconnected
+* reconnect(``transport_type``, ``reconnectionAttempts``): fired when a reconnection is attempted, passing the next delay for the next reconnection.
+
+---
+
+These things and more!
+======================
+
+This presentation has a some source online:
+
+* http://github.com/miamiwebstaff/pysoflo
+* http://github.com/nyxtom/
+* http://github.com/nyxtom/saywhat