Slides from LAX & DEN usergroup meetings

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Bunch of user groups… Kevin Schroeder

Technology Evangelist

Zend Technologies


About me

• Kevin Schroeder Technology Evangelist for Zend

Programmer

Sys Admin

Author• IBM i Programmer’s Guide to PHP

• You want to do WHAT with PHP? – Coming up

Race Ferraris on the weekend• My Honda has a dismal win record


I blog at eschrade.com

Follow us!

Zend Technologies

http://twitter.com/zend

http://twitter.com/kpschrade (me!)


A quick note on Zendcon… BE THERE!!

•Learn PHP best practices•Discover new advances •Gain new insights•Deploy and scale large PHP applications•Explore new technologies like NoSQL and Cloud Computing•Learn how to effectively leverage Zend Framework and Zend Framework 2.0


Agenda

• You choose

• Seriously (ad hoc is fun)

• But if not Intro to Zend/Zend Products

Deployment

Unit Testing

Queuing/Scalability


Why do we use PHP?


What does Zend do

• Zend Framework

• Zend Studio (8.0 in public beta 1)

• Zend Server Monitoring,

Code tracing (freaking cool!!)

Job queuing

HA Session Clustering

• Zend Server Cluster Manager Does all of that in a clustered environment


Zend Server


Zend Server

• The primary reason to use Zend Server is insight What went wrong?

Who did it happen to?

What do I need to do to fix it?


Why do we need diagnostic tools?


Let’s slow that down a bit


• There are several useful features in Zend Server 5

Code Tracing/Monitorin

gJob Queue Session

Clustering Optimizer+ Native installation

Zend Framework Apache or IIS integration Java connector

Web-based administrator

console

Debugger interface

Caching API Page cachingZend Download Server (Linux

only)

Software updates and hot fixes Technical support


Deployment


Before we get going

• Who here is a developer?

• Who here is a system administrator?

• Who here has an existing deployment strategy?

• Who here has edited a file in production?

• Who here has wished they hadn’t?


Application Stages

| 15

Increasing Maturity of PHP Applications

Development Testing/QA Staging Production


Maturity

| 16

Increasing Maturity of PHP Applications

Testing & Validating

Application

Testing & Validating

Environment

Benefit

Structure

Distinct Dev Environments

Uptime!!

Where are you?


Application considerations

• Build the application to be aware of different environments Zend_Config_* is good at this

• Do not set the environment type in your code Environment variables can be placed in server config

• It means that you won’t accidentally keep your development settings turned on in production

• Make production your default environment Keeps accidental data leakage to a minimum

bit.ly/phpDepApp


Deployment Option 1 – rsync

• Benefits Easy

Already installed on your system

• Drawbacks No deployment script can be run

Not integrated with either PHP or the OS

Rollbacks require rolling back the entire source server• Does not understand versioning

– One option is to move the source tree prior to the rsync

• Uses xinetd

bit.ly/phpDepRsync


Deployment Option 2 – Source Control

• Benefits Easy

You should already be using source control

Has versioning

Can have pre/post install scripts

Easy to do automatic deployments

• Drawbacks Do you want to put details on how to access your source

code on your production box?

Requires that your source control is accessible from production

Deny access to .svn directories

bit.ly/phpDepSVN


Deployment Option 3 – PEAR• Benefits

Designed for PHP

Very scriptable• Natural for doing things like clearing a cache

Has a better understanding of PHP

Cross platform compatible

• Drawbacks Requires admins to be familiar with PHP code

Limited to PHP deployment

Available tooling is restrictive/build your own package.xml

Define standardized locations (www, library, etc.)

bit.ly/phpDepPEAR


Deployment Option 3 – PEAR

Creating your PEAR Channel

pear channel-discover pear.pirum-project.org

pear install pirum/Pirum-beta

vi /var/www/pear/pirum.xml

<server> <name>qa/pear</name> <summary>OurOrg PEAR channel</summary> <alias>helloworld</alias> <url>http://qa/pear/</url></server>

php ./pirum build /var/www/pear/


Deployment Option 3 - PEAR

Creating your PEAR package

php ./build-pear.php

pear package

pirum add /var/www/pear/ HelloWorld-0.1.3.tgz


Deploying your app

pear channel-discover qa/pear

pear config-set www_dir /var/www

pear install helloworld/HelloWorld

pear clear-cache

pear upgrade helloworld/HelloWorld

Roll Back

pear uninstall helloworld/HelloWorld

pear install helloworld/HelloWorld-0.1.3


Deployment Option 4 - OS-based

• Benefits Easily added as part of your server deployment

• Very cloud friendly

Admins already know how to use it

Can describe OS-requirements/dependencies

Downtime limited to actual install, not network transfer time

• Drawbacks Depends on environment

Any PHP deployment scripting needs to be deployed with the application and executed in %post hook

bit.ly/phpDepYum


Which should you use?

• Need something simple? rsync

• Need to deploy to multiple disparate platforms? PEAR

• Need to deploy internally/with minimal developer input?OS (yum/apt) If using the OS consider maintaining an internal “blessed”

repository instead of depending on the distribution


Which should you use?

• Need something simple? rsync

• Need to deploy to multiple disparate platforms? PEAR

• Need to deploy internally/with minimal developer input?OS (yum/apt) If using the OS consider maintaining an internal “blessed”

repository instead of depending on the distribution


Continuous Deployment

• Using automated deployment

• Very tight end-to-end integration

• Requires a lot of trust that the developers have a fully tested application w/ backend and frontend code

• Probably more work to manage if you can count the servers in your production environment with your fingers

• Could be beneficial but make sure you know what you’re doing You will need to have several testing experts

• Also…

Look at what happened the last time we gave control to the

machines

It didn’t work out so well for the humans


Takeaways

• No need for copy-and-paste deployment

• No need for (S)FTP

• Have an easy rollback mechanism

• Prepare for errors in deployment

• Try to minimize the amount of scripting needed for deployment

• Consider using VMs on anything important to keep downtime to zero


Unit Testing


Unit Testing - partially stolen from Matthew Weier O’Phinney

• Why Unit Test? Simplify maintenance

It defines expectations

It describes behaviors identified by the application

It tells us when new changes break existing code and behaviors


Terms

• Unit Test The piece of code you are testing

• Test A piece of code that calls the piece of code you’re testing

• Assertion Validating return types or results of the test

• Code Coverage A report on which lines of code have been tested

• Used to determine additional tests that need to be written

• Continuous Integration The continuous application of quality control, i.e. unit tests


Unit Testing – What to use

• PHP testing frameworks PHPT Used by PHP, and some PEAR and independent libraries

• SimpleTest JUnit-style testing framework

• PHPUnit JUnit-style testing framework

De facto industry standard


Writing Unit Tests

• Create a test class

• Create one or more methods describing behaviors State the behaviors in natural language

• Write code that creates the behavior(s) Write code exercising the API

• Write assertions indicating expectations


Examples

• Example 1 – Creating a Unit Test for a model in Zend Studio

• Example 2 – Creating a Unit Test based off of Code Coverage

• Example 3 – Testing a Zend Framework controller Using Zend_Test_PHPUnit_ControllerTestCase


Queuing/Scalable computing


Queuing/Scalable computing

• An interesting problem Nobody has built a fully scalable application


Typical anatomy of a PHP Application

PHP: Past and Present

| 37

Presentation

Application Control

Database Access

Business Logic

Presentation

Application Control

Business Logic

Presentation

• Not so good for defining small bits/queuable functionality


Options

• Use Cron

• Use Gearman

• Use home-grown (don’t do this)

• Use Zend Server Job Queue


Characteristics

• Allow for a sledgehammer to hit a machine Scalability and High Availability are yin and yang

• A site that can’t keep running is not scalable

• A site that can’t scale will fail (if it gets really popular)


Considerations

• Waste disk space

• Control usage (don’t let users do anything they want)

• Pre-calculate as much as possible Calculate and cache/store

• Don’t scan large amounts of data

• Keep data processing off the front end servers

• Don’t just cache Don’t let it substitute for thought

Cache hit rates can be meaningless if you have hundreds of cache hits for a request


Considerations

• Build a deployment mechanism with NO hardcoded values

• Decouple/Partition Don’t tie everything into the database

• Use queues/messaging Stomp interfaces are really good for PHP


The Golden Rule of Scalability“It can probably wait”


When do you not need current data

• Credit card processing?

• Request for the front page?

• Sign in?

• Viewing a shopping cart?

• Displaying a page with ads?

• Answer? Almost always

Data is “out of date” once it leaves the web server


What could this look like?


Let’s write some code(if we have time)

(no I’m not copping out. We’re all told to show our work in grade scool)


Follow us!

Zend Technologies

http://twitter.com/zend

http://twitter.com/kpschrade (me!)


Get this information and all the examples at eschrade.com…


Remember… BE THERE!!

•Learn PHP best practices•Discover new advances •Gain new insights•Deploy and scale large PHP applications•Explore new technologies like NoSQL and Cloud Computing•Learn how to effectively leverage Zend Framework and Zend Framework 2.0