PHP Performance – Webinar - Zend

PHP PERFORMANCE Principles and Tools By Kevin Schroeder Technology Evangelist Zend Technologies

Copyright © 2007, Zend Technologies Inc.

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

• If you have a question you can
Type in the Q&A panel
Tweet #zendperf

• Follow us!
http://bit.ly/cjueZg (or search for Zend)
http://twitter.com/zend
http://twitter.com/kpschrade (me!)

Things we’ll look at • • • • • •

Database Network Latency IO Contention CPU utilization Network Connectivity Best Practices/Pit Falls/Things to consider

Performance – Database • Tools
Zend Server – A distinct group of monitoring options for DB’s
Inter-application query monitoring, usually via a DB adapter abstraction layer

• Symptoms
Pages take a long time to load with Apache/IIS/PHP using proportionally less of the CPU time

• Causes
The list could go on for 1x105 slides

Performance - Database • Possible remedies
Simplify your queries
Make your queries more complex
Tune your database

Performance – Network Latency • Tools
Zend Server – monitor slow socket function execution
Wireshark
Tcpdump

• Symptoms
Depends on where the latency is occurring
Often slow page responses with low CPU usage

• Causes






Network Saturation (probably not too likely) DNS Reverse Lookups TCP Handshakes High number of “hops” … and much more

The TCP handshake

T/TCP

SYN +

Respon s

e Data

+ FIN

N K +FI C A ta + se Da n o p Res YN + S P T/ TC ACK

Hops (not the good kind) Server

Client

HTTP – Layer 7

HTTP – Layer 7

UTF-8 – Layer 6

UTF-8 – Layer 6

Switch/Router TCP – Layer 4

TCP – Layer 4

IP – Layer 3

IP – Layer 3

IP – Layer 3

IP – Layer 3

Ethernet – Layer 2

Ethernet – Layer 2

Ethernet – Layer 2

Ethernet – Layer 2

Physical – Layer 1

Physical – Layer 1

Physical – Layer 1

Physical – Layer 1

Performance – IO Contention • Tools
Zend Server (in extreme cases, long fopen() calls)
vmstat & top (Linux)
System Internals Process Explorer (Windows)

• Symptoms
Unpredictable and difficult to reproduce page load times

• Causes
Too few spindles serving too much data
High write concurrency
Insufficient free system RAM

Performance – CPU Utilization • Tools
top (Linux)
System Internals Process Explorer (Windows)

• Symptoms
Page load times either correspond directly to CPU utilization or are consistently slow

• Causes





Bad code or over-architected solutions Excessive recursion Excessive IO High server utilization • too few servers serving too much traffic

Performance – CPU Utilization • There are often 2 different paths this can follow
User time • Time spent executing the code that you wrote


System time • Time spent running functionality that your code calls, such as networking, file system, etc.

Performance – Network Connectivity • Tools
Zend Server – monitor failed calls to socket_connect(), fsockopen() or fread()
Wireshark
Tcpdump

• Symptoms
Database or web service calls take long to execute
If read functions die unexpectedly, bad network hardware might be a cause

Choosing the right architecture • If you deal with large collections of data, be careful of various ORM techniques or data access methods. This can pertain to the cloud too Limit 100

Limit 500

Limit 1000

Unlimited (250k)

Active Record

0.056

0.27

0.55

13.3

Collection

0.002

0.008

0.01

0.2

28

33.75

55

66.5

Difference (Col * Dif) = AR

OO • Beware of magic!
__get, __set, __call
Situations where they are often used • When representing another object that it has no knowledge of I.e. Soap requests, COM objects, Java objects, database tables • When there are property-level permissions on an object’s properties. Keeping the properties private and using __get/set to determine access


If used sparingly they won’t affect you, but many modern applications have lots of recursion or large underlying architectures that can have unpredicted consequences

!Preg • Use preg_match for data checking only when you have to
stripos(‘http://’, $website) is over twice as fast as preg_match(‘/http:\/\//i’, $website)
ctype_alnum() is almost 5 times as fast as preg_match(‘/^\s*$/’);
Casting “if ($test == (int)$test)” is well over 5 times faster than preg_match(‘/^\d*$/)

Code Acceleration • From a test on Wordpress
Without acceleration • Requests per second: 2.28 • Time per request: 437.766 ms


With acceleration • Requests per second: 8.11 • Time per request: 123.377 ms


4-fold increase in performance by flipping a (free) switch
Zend Server CE is free and has this. You have no excuse!!

Do you queue? • Offloading long running processes to a queuing •

system can help make your front end servers scale more vertically Examples include
Job Queues • Zend Platform/Zend Server 5 • Gearman


Message Queues • ActiveMQ • RabbitMQ

What not to do • This is not complete!!!
“Oh we’ll just cache it”
“Our NFS server is just fine for serving PHP files”
“That LIKE query is necessary” • You may need to structure your data a little different • You might need to use a search engine instead • Zend_Search_Lucene • SOLR


“Using arrays is faster than objects, we’ll use them instead”
“Monitoring/diagnostic tools are too expensive”

What TO do • This is not complete!!!
Minimize require_once calls/use an autoloader
Try to make your architecture more horizontal rather than vertical • People from Java backgrounds tend to go more vertical


Use Lazy Loading/Load on Demand
THINK before you code!! • Don’t just do something because someone else is


Use diagnostic tools! • Zend Server Monitoring and Code Tracing • Zend Studio Profiler (pays for itself if you are 0.5% more productive in a year (according to my calculation)

Non-PHP PHP performance rules • PHP performance is not the only factor in determining the overall performance of a website. Here are some suggestions








Make fewer HTTP requests Use an Expires header Gzip cached content Put stylesheets at the top Put Javascript at the bottom Reduce DNS lookups Avoid redirects

Non-PHP PHP performance rules • Be aware of your page size





Microsoft – 238kb – 4.4 seconds Oracle – 104kb – 861ms IBM – 640 kb – 4.6 seconds Zend – 183kb – 2.4 seconds

• There is a fairly direct relationship between the amount of data on your web page and the render time

Non-PHP PHP performance rules • Similarly, be careful when dealing with lots of Ajax • • •

data The browser needs to process that data With large data sets the browser may take a while to update the DOM 2 options
Use staggered loading
Pass rendered content to the browser and attach with innerHTML

Questions?

Fin Kevin Schroeder [email protected]