Auto-scaling PHP applications using Chef and AWS

Given at PHPSW in Bristol on 12th February 2014.

Transcript

1. Auto-scaling PHP applications using Chef and AWS Andy Gale Web Consultancy
2. About me Andy Gale Web Consultant Hello Future http://hellofutu.re ! @andygale @hellofutur3 Web Consultancy
3. Hosting Web Consultancy Virtual machine or cloud instance
4. Traffic Web Consultancy 0 1000000 2000000 3000000 4000000 00:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 Visitors
5. Crash!
6. Hosting Web Consultancy Dedicated machine
7. Crash!
8. Separate Database and Web Web Consultancy
9. Crash!
10. Horizontal scaling Web Consultancy
11. Great success!
12. Traffic Web Consultancy 0 1000000 2000000 3000000 4000000 00:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 Visitors
13. Web Consultancy
14. Auto-scaling Web Consultancy • Only pay for capacity we use • Handle huge traffic peaks • Automatically recover from failure
15. Web Consultancy When your traffic increases, our robot will automatically create a new web server for you.
16. • Cloud hosting provider • Various services • We’ll be using Elastic Load Balancers, EC2 (Elastic Compute Cloud) and RDS (Relational Database Service) What is AWS? Web Consultancy
17. Auto-scaling Web Consultancy • Create new web servers • Use ELB load balancer • Use Amazon RDS database which will in this example will need to be large enough to handle our traffic peaks
18. Auto-scaling Web Consultancy • We’ll need a way of setting up web servers • And we’ll need a way of installing our code on to them
19. • Configuration management tool • Install packages • Ensure services like Apache are running • Write out configuration files from templates • Restart services when templates change What is Chef? Web Consultancy
20. Web Consultancy Collections of recipes, templates and other configuration attributes to get stuff done. Chunks of Ruby code that describe what stuff we need to do to get that stuff done. Cookbooks Recipes
21. Web Consultancy A virtual machine, cloud server or dedicate server Resource Creates a user, expands a template, installs a package, starts a service etc Node
22. Web Consultancy Port number, database name, file location etc Template A template which you create a file from inserting variables Attribute
23. Web Consultancy package "ntp" do action :install end ! template "/etc/ntp.conf" do source "ntp.conf.erb" owner "root" group "root" mode 0644 notifies :restart, resources(:service => "ntp") end ! service "ntp" do action :start end Install package Create config file from template Define service and start NTP Restart service when config file changes
24. Web Consultancy Let’s make a cookbook to install our PHP application
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26. Web Consultancy Our template <VirtualHost *:80> ServerName <%= @params[:server_name] %> DocumentRoot <%= @params[:docroot] %> ! <Directory <%= @params[:docroot] %>> Options FollowSymLinks AllowOverride FileInfo Options AllowOverride All Order allow,deny Allow from all </Directory> ! <Directory /> Options FollowSymLinks AllowOverride None </Directory> ! </VirtualHost>
27. Web Consultancy include_recipe "apache2" include_recipe "php" include_recipe "php::module_mysql" include_recipe "apache2::mod_php5" Our recipe
28. Web Consultancy web_app node['phpapp']['host'] do template "phpapp.conf.erb" docroot node['phpapp']['dir'] server_name node['phpapp']['host'] end Our recipe
29. Web Consultancy gettingstartedwithchef.com
30. Web Consultancy $ knife ec2 server create --run-list "role[phpapp]" -I ami-3d160149 --region eu-west-1 -G www,default -x ubuntu -- node-name server01 --identity-file ~/.ssh/sshkey.pem Create EC2 instance
31. Auto-scaling Web Consultancy • We want to auto-scale quickly • Our previous Chef and knife example takes 10 minutes to bootstrap our server
32. Auto-scaling Web Consultancy https://github.com/hellofuture-cookbooks/hf-lamp hf-lamp • Different recipes for installing dependencies and setting up you application configuration
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34. Web Consultancy include_recipe "apache2" include_recipe "php" include_recipe "php::module_mysql" include_recipe "apache2::mod_php5" Auto-scaling
35. Auto-scaling Web Consultancy • chef-solo to create an instance with dependencies installed • Create an AMI image from that instance • Use that instance in you auto-scaling launch configuration
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45. When to auto-scale Web Consultancy ! • Create CloudWatch alarms on key metrics such as CPU load • Scale up when a high percentage of total of the metric is being used • Scale down when low percentage of the metric is being used
46. When to auto-scale Web Consultancy ! • Test things out with CloudWatch alarms to begin with • Scale up quickly and scale down slowly
47. Amazon OpsWorks Web Consultancy ! • Chef based • Lots of scaling configuration options including scaling up on a schedule
48. Questions? Web Consultancy