Scalability Research
j0zf 2009.7.5

// GOALS ///////////////////////////////////////////////////////////////////////

1. Scalability
2. Redundency
3. Fail-Over
4. PCI Compliance
	- check list : https://www.pcisecuritystandards.org/education/docs/Prioritized_Approach_PCI_DSS_1_2.pdf

// OPTIONS ///////////////////////////////////////////////////////////////////// 

> Cloud Servers
	> RackSpace Cloud http://www.rackspacecloud.com/
		- may request separate geographic locations for servers.
		- very liberal policy, it just has to be legal.
		- Load balancing is DIY
		- Additional Public IP addresses are $2 / month. (request from support)
	> Amazon EC2 http://aws.amazon.com/ec2/
		- may have policy limiting direct marketing, and content. http://aws.amazon.com/agreement/
	> SoftLayer http://www.softlayer.com/
		- Does Load-balancing (no real clear)
		- More expensive than Rackspace (on average)
	> Google App Engine - http://code.google.com/appengine/
		- ""Lavin" (12:34:44 PM): but that we would have to rewrite our entire system into python"

> In House Servers
	- Possibly using load balancing hardware
	pros:
		- direct access to servers and hardware.
	cons:
		- cost of bandwidth
		- up-front cost of servers	
	
> Rented Servers (Hostgator, etc)
	> Multiple Dedicated Servers
		- x number of webservers using rsync
		- use round-robin dns method
		- dedicated database server
	> Hosting service which provides Load Balanced Servers
		- http://www.eliterax.com/server-clusters/

> Load Balancing
	> Apache HTTP Server (mod_proxy_balancer)
		-	howto: http://www.howtoforge.com/high_availability_loadbalanced_apache_cluster	
	> DNS Load Balancing Options
			* Round robin DNS http://en.wikipedia.org/wiki/Round_robin_DNS
				- DnsMadeEasy Round-Robin Load Balancing http://www.dnsmadeeasy.com/s0306/res/recs.html#rr
					- ?? Can we do this same thing, in-house?
			* Apache Load Balancing 
				- mod_proxy_balancer extension
				- apache2-mpm-worker is pretty fast and light if well-configured.		
			* Pound
				- http://www.debian-administration.org/article/Simple_webserver_load_balancing_with_pound	
			* NginX
				- http://en.wikipedia.org/wiki/Nginx
				- http://sameerparwani.com/posts/load-balancing-with-nginx/
			* For Failover
				- heartbeat or something similar would do the failover		

> Database Scaling
	- Phase 1 : Powerful Single-Purpose MySQL Database Server.
	- Phase 2 : Mysql Cluster
		- http://www.mysql.com/products/database/cluster/faq.html

// POTENTIAL OBSTACLES /////////////////////////////////////////////////////////

- Multiple wildcard SSL certs on the same server.
	- josephl_	Hydra wants to use their own wildcard SSL certificate rather than the product2web.com one
		
// RESEARCH SOURCES ////////////////////////////////////////////////////////////

http://en.wikipedia.org/wiki/Cloud_computing
http://www.rackspacecloud.com/cloud_hosting_products/servers
josephl:	http://porteightyeight.com/2008/03/24/the-hitchhikers-guide-to-php-load-balancing/ <--- this is a neat little guide I found that gives a general introduction
Byron: http://www.dnsmadeeasy.com/
http://en.wikipedia.org/wiki/Load_balancing_(computing)
http://en.wikipedia.org/wiki/Round_robin_DNS
http://www.zytrax.com/books/dns/ch9/rr.html  (HOWTO - Configure Load Balancing)
http://www.softlayer.com/
http://www.mysql.com/products/database/cluster/faq.html
http://video.google.com/videoplay?docid=-4567104036778249401
http://www.howtoforge.com/high_availability_loadbalanced_apache_cluster
http://www.howtoforge.com/load_balancing_apache_mod_proxy_balancer
http://www.markround.com/archives/33-Apache-mod_proxy-balancing-with-PHP-sticky-sessions.html
http://httpd.apache.org/docs/2.2/mod/mod_proxy.html#proxypass
http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html
http://highscalability.com/myspace-architecture


Setting Up A High-Availability Load Balancer (With Failover and Session Support) With HAProxy/Keepalived On Debian Etch
	http://www.unix-tutorials.com/go.php?id=3141
	
How To Set Up A Load-Balanced MySQL Cluster 
	http://www.unix-tutorials.com/go.php?id=496

Squid: Optimising Web Delivery	
	josephl: I've been reading about high scalability, alot of people seem to use this
	http://www.squid-cache.org/ 

MySpace Architecture : High Scalability Building bigger, faster, more reliable websites
	http://highscalability.com/wikimedia-architecture
	
HA-Cluster with loadbalancing for Zope (and Plone)	
	http://plone.org/documentation/how-to/ha-load-balanced-cluster-for-zope-and-plone

Highly Available Networks - 1996 HP, Pamela Dickerman, Michael Hayward
	http://docs.hp.com/en/198/wpnetwork.pdf
	
Hacker News | Why are Facebook, Digg and Twitter So Hard To Scale?
	http://news.ycombinator.com/item?id=879497


// CLIENTS /////////////////////////////////////////////////////////////////////

> By...
	- Has now:
		- 1 server.
		- backing up to 2nd server.
		- dns fail setup. via dns made easy.
	- Needs:
		- pci compliance, separate server.
			- need a pci server.
		- 5 or 10 crm carts on each server.
		- 1 server, all landing pages, needs to be fast.
		- 1 server, backend crm server, needs to be stable.
		- cluster situation, they host their front end landing pages.
	
> Hy...
	- Their own wildcard SSL certificate rather than the product2web.com one.