Stefan Didak's presentation about APC, memcached, varnish, and other tools for speeding up your WordPress site (as long as you're in charge of your own server). From the October 2013 East Bay WordPress Meetup.

1. EAST BAY WORDPRESS MEETUP
HOW TO MAKE WP FLY...
LIKE A BAT OUT OF HELL
Sunday, October 6, 13

2. EXPLAINING
THE SECRETS
BEHIND MANAGED
HOSTING AND REALLY
FAST WORDPRESS SITES
THE ALTERNATIVE TITLE
I could have renamed this presentation
Sunday, October 6, 13

3. Stefan Didak
http://www.stefandidak.com
(“not a web developer”)
Sunday, October 6, 13

4. The sound a WordPress site
should make when your client is
happy to pay you more because
their site is so fast that it puts
their competition to shame.
TIME = MONEY
Sunday, October 6, 13

5. Caching provided by optimizing your site
Caching through plugins
Caching because of all of the above
As you’ve already been shown today
LEVELS OF CACHING
all of those make a difference but... NOT ENOUGH
Sunday, October 6, 13

6. Don’t just optimize your site
Optimize YOUR SERVER!
and if you have none, build one!
Optimize YOUR CODE TOO!
LEVELS OF CACHING
Everything I’m going to show today requires you to have full
control and access to your server (VM, VPS, Cloud, etc.)
Sunday, October 6, 13

7. WordPress Caching
Digital Ocean + DEMO
OpCode Caching
Apache v.s. Nginx
Varnish
Memcached
WHAT I’LL BE COVERING
Also known as the Tip of the Iceberg
Sunday, October 6, 13

8. WP CACHING OVERVIEW
Everyone should know what levels of caching WP supports
Sunday, October 6, 13

9. Only lasts the duration of the request.
After the request the run-time cache no
longer exists.
For example: the global $post and
$wp_query variables
WORDPRESS CACHING
Run-Time Cache
Sunday, October 6, 13

10. WordPress has a “Transient Cache” API
that allows you to store data in
your MySQL DB.
Ahum... Right...
But it can still be useful...
if used selectively
WORDPRESS CACHING
Transient Cache
Sunday, October 6, 13

11. Is usually persistent because it’s stored
“somewhere”.
Somewhere could be in memory through
APC, Memcached, or Redis, but could also
be in your MySQL DB or on disk.
WORDPRESS CACHING
Object Cache
Sunday, October 6, 13

12. Stores HTML data representing entire
pages. This is one of the more typical
caching schemes used by most plugins.
Unfortunately, not so useful when you have
highly dynamic pages where someone does
not always get the same content (i.e.
membership sites).
WORDPRESS CACHING
Page Cache - Stored on disk or in memory
Sunday, October 6, 13

13. I don’t like the term and it is no different
from the Object Cache. Instead of storing
entire HTML pages it stores parts of pages.
I like to think of it as just another object
because that’s what it is.
WORDPRESS CACHING
Fragment Cache
Sunday, October 6, 13

14. I prefer to have full control
over my own online servers
because I can have them be
faster than managed hosting
at a fraction of the cost.
PERSONAL EXPERIENCE
Managed Hosting, however optimized, is still designed to be a
version of a “one size fits all” approach
Sunday, October 6, 13

15. GREAT(ER) PERFORMANCE
& OK PRICES
GREAT PERFORMANCE
& COOL PRICES
SLOW & EXPENSIVE
Sunday, October 6, 13
NICE PERFORMANCE
& CAN GET EXPENSIVE

16. After running and testing my first
“droplet” on Digital Ocean and after
playing with some deployments on
Linode I knew my shared hosting for
30+ domains would come to an end.
A very WELCOME END!
FIRST DEPLOYMENT
It was really exciting to see my first droplet come online
Sunday, October 6, 13

17. If you don’t care much
about the “managed” part
of managed hosting and
really want things to roar
like a bat out of hell...
HOSTING, BUT WHERE
The long search has come to an end
Sunday, October 6, 13

18. Once my “stealth project” goes live I
expect that within 2 years I will need
around 150 to 500 virtual servers.
(virtual servers of various capacities)
Digital Ocean has the absolute best
price point I’ve seen. And I’ve been
looking. Really looking.
STEALTH PROJECT
Not to mention, Digital Ocean has a nice evolving API to
manage all your “droplets”. Not as mature as Linode, though!
Sunday, October 6, 13

19. $20/mo shared hosting
v.s.
$5/mo Digital Ocean Droplet
Oakley Chamber of Commerce
WordPress site
(a heavy and NOT OPTIMIZED one!)
DEMO TIME ! DEMO TIME !
If this doesn’t convince you I don’t know what will
Sunday, October 6, 13

20. http://oakleychamber.com
http://oc.ignyter.com
TRY IT FOR YOURSELF
anyone with laptops here are encouraged to check it out
Sunday, October 6, 13

21. WAS THAT FAST
OR WAS THAT FAST?
Or is it just cool to know
that you can do it TOO!?
YES YOU CAN
Stop whining about the commandline and typing on the
keyboard, as if you don’t do that crap when you’re CSS’ing!!!
Sunday, October 6, 13

22. I can’t show you managed
hosting vs. Digital Ocean at
a $25-30/month vs. $5-10/
month price point...
BUT....
Sunday, October 6, 13

23. I will take any bet, for any amount of
serious money, that I can setup and
configure servers on Digital Ocean or
Linode that beat the living daylights
out of any managed hosting in terms
of performance.
And YOU can do it TOO!
So let’s not even talk about
shared hosting anymore, ok?
Sunday, October 6, 13

24. I know what I’m doing and...
may be biased.
I do, however, believe, that if you put
in some time to learn more than what
you copy & paste will serve you to be
even more valuable to your clients!
COPY AND PASTE
If you can’t do copy and paste then I’m wasting your time and I
am very sorry. If you can, however... new doors will open!
Sunday, October 6, 13

25. https://www.digitalocean.com/community
https://library.linode.com/
TUTORIALS, GUIDES, AND MORE
INSTALLING AND RUNNING
On how to install, configure, and run with all the things I
mentioned today, visit the libraries.
Sunday, October 6, 13

26. OPCODE CACHING
And now to explain what you’ve just seen
Sunday, October 6, 13

27. What your server does for EVERY page hit
on your site:
Read most (or all) of your PHP files/code
Interpret each line & “compile” it into what
the CPU understands
Execute the “compiled” code and render out the
page by sending it to the browser.
OPCODE CACHING
Yeah, uh, sure, what what does it DO?!
Sunday, October 6, 13

28. What your server does for EVERY page hit
on your site:
Read most (or all) of your PHP files/code
Interpret each line & “compile” it into what
the CPU understands
Execute the “compiled” code and render out the
page by sending it to the browser.
OPCODE CACHING
Yeah, uh, sure, what what does it DO?!
Sunday, October 6, 13

29. WITHOUT OPCODE CACHING
PHP
PARSE
PHP
APC
CACHE
COMPILE
EXECUTE
SEND
EXECUTE
SEND
WITH OPCODE CACHING
OPCODE CACHING
The simple explanation
Sunday, October 6, 13

30. APC
XCache
eAccelerator
Zend OpCache
NuSphere PHPExpress
IonCube Accelerator
OPCODE CACHING
Speeds up your site much more than “regular” file/data caching
Sunday, October 6, 13

31. Because APC is going to
be included in “PHP6”
But as we all know, there is no such thing as PHP6, right?
There is a book on PHP6.
But there is no Beta of PHP6.
There isn’t even an Alpha of PHP6.
BUT PHP 5.5 HAS OPCACHE
Performance between APC, XCache, etc. is all very similar
Sunday, October 6, 13

32. PHP APC
APC = Alternative PHP Cache
Sunday, October 6, 13

33. Without APC
With “vanilla” APC
Req. Per Sec : 85
Time Per Req. : 900ms
Conc. Time Per Req. : 20ms
Xfer Rate : 898 Kbytes/s
Req. Per Sec : 138.5
Time Per Req. : 476ms
Conc. Time Per Req. : 9.5ms
Xfer Rate : 1265 Kbytes/s
Great, but...
IS THAT ALL?
BENCHMARKING APC
Your site without APC sucks donkey balls
Sunday, October 6, 13

34. Without APC
With “vanilla” APC
Req. Per Sec : 85
Time Per Req. : 900ms
Conc. Time Per Req. : 20ms
Xfer Rate : 898 Kbytes/s
Req. Per Sec : 138.5
Time Per Req. : 476ms
Conc. Time Per Req. : 9.5ms
Xfer Rate : 1265 Kbytes/s
Now with apc.stat=off
Req. Per Sec : 317.4
Time Per Req. : 152.1ms
Conc. Time Per Req. : 3.1ms
Xfer Rate : 3985 Kbytes/s
BENCHMARKING APC
Your site with APC and apc.stat = off WILL FLY!
Sunday, October 6, 13

35. Only turn APC.STAT to OFF if:
Your PHP code on the server does not
change and you are willing to restart
the web server if it does.
WP or Plugin updates =
CHANGE OF PHP CODE
APC.STAT = OFF
THINK AND PLAN BEFORE YOU TURN IT OFF
Sunday, October 6, 13

36. # /etc/init.d/apache2 restart
It’s just one line. Maybe not exactly
the same as this one, though.
And it’s only for a few seconds.
RESTARTING? SO WHAT?
There are other ways to deal with this but those are for
another time when we get real deep into server stuff
Sunday, October 6, 13

37. Ensure your server has:
php-pear, php5-dev, make, apache2-prefork-dev
# pecl install apc
Then add the extension to your php.ini (or other)
extension=apc.so
INSTALLING APC
Because it might be different for your flavor of server I’m not
going into too much detail here, but it’s dead easy
Sunday, October 6, 13

38. apc.enabled=1
apc.shm_segments=1
apc.shm_size=128M (or 1G, etc.)
apc.ttl=3600
apc.user_ttl=7200
apc.gc_ttl=3600
apc.max_file_size=1M
apc.stat=1 (or 0)
CONFIGURING APC
You should tweak it as much as needed
And there’s a lot more you can tweak in APC
Sunday, October 6, 13

39. With APC installed you can use PHP
function calls to...
Manage the APC cache
Interrogate the APC cache
Load/Dump Binary cache data
START OPTIMIZING YOUR CODE
Integrate it selectively in your plugins
WORTH KNOWING
APC will also extend PHP with new functions
Sunday, October 6, 13

40. APC Object Cache Backend
http://wordpress.org/plugins/apc/
Place the object-cache.php
in your wp-content directory.
Optionally you can also install the
BATCACHE plugin
APC WITH A WP PLUGIN
Your mileage may vary
Sunday, October 6, 13

41. Apache = Process Based
Nginx = Event Based
APACHE V.S. NGINX
Because you might get a lot of visitors... all at the same time!
Sunday, October 6, 13

42. Asynchronous
Asynchronous = Scalability
Fewer Server Resources
(i.e. much less memory)
Better for heavy load sites
A FEW ADVANTAGES
On sites with light traffic you will not see much difference in
performance between event vs. processed based servers
Sunday, October 6, 13

43. 10.000 concurrent connections
and Nginx still uses only a few MB of
memory
Apache... 100’s of MB’s
And often will not even handle the load.
ALSO A COST DIFFERENCE
Part of the cost of virtual servers is the amount of memory that
is available. Disk space is not as important as memory.
Sunday, October 6, 13

44. Back in 2008...
8000 live traffic requests per second
Apache would have fallen over
and DIED
WORDPRESS.COM
Big servers and big sites prefer Nginx... and now you know why
Sunday, October 6, 13

45. 15MB of RAM and
10% of CPU resources
Apache and a pound load balancer
would freak out at the 1000th
process, using 400+MB RAM and
“leaking” 20MB RAM per hour
GAME OVER
Big servers and big sites prefer Nginx... and now you know why
Sunday, October 6, 13

46. WP development is “intertwined”
with the Apache world.
Support is “limited but growing”.
http://codex.wordpress.org/Nginx
http://wiki.nginx.org/WordPress
WORDPRESS & NGINX
Not quite a match made in heaven
You’ll have to do some marriage counseling
Sunday, October 6, 13

47. Nginx has no conceptual notion of
this thing called an .htaccess file
http://wordpress.org/plugins/nginx-helper/
Search for Nginx related WP plugins
WORDPRESS & NGINX
WHERE THE HECK DID MY .HTACCESS FILE GO?!
Sunday, October 6, 13

48. Caching HTTP Reverse Proxy
Proxy Servers are not just “the thing you set in your browser”
Sunday, October 6, 13

49. BROWSER
BROWSER
PROXY
SERVER
VARNISH
WEBSITE
WEBSITE
With Varnish YOU control the caching
(because not everyone uses a proxy)
VARNISH
And it really is... really really, really, REALLY FAST!
Sunday, October 6, 13

50. Cache on Disk
Cache in Memory
Control through VCL
(Varnish Cache Language)
VARNISH
You control the proxy and you control the resources
Sunday, October 6, 13

51. VARNISH
PORT 80
APACHE OR NGINX
PORT 8080
http://mysite.com
http://mysite.com:8080
Varnish points to a “backend” server
which happens to be itself but with
the web server on a different port
VARNISH SAME SERVER
Change the web server port to something else because
Varnish should respond on port 80
Sunday, October 6, 13

52. VARNISH
PORT 80
APACHE OR NGINX
PORT 8080
http://mysite.com
http://somesite.com
http://wowy.com
http://admin.com
http://mysite.com:8080
http://wowy.com:8080
APACHE OR NGINX
PORT 8081
http://somesite.com:8081
http://admin.com:8081
VARNISH DIFFERENT SERVERS
You can do the setup in whatever way you like
Sunday, October 6, 13

53. # Drop any cookies sent to Wordpress.
sub vcl_recv {
! if (!(req.url ~ "wp-(login|admin)")) {
! ! unset req.http.cookie;
! }
}
# Drop any cookies Wordpress
# tries to send back to the client.
sub vcl_fetch {
! if (!(req.url ~ "wp-(login|admin)")) {
! ! unset beresp.http.set-cookie;
! }
}
WP AND VARNISH
BEWARE OF COOKIES
Sunday, October 6, 13

54. MEMCACHED
The name of the game is “DISTRIBUTED”
Sunday, October 6, 13

55. The “for dummies” version:
Make better use of memory
Cache data in memory on
other servers that aren’t
using it as much.
AND IT DOES WHAT?
It manages cache and memory... for more than one server
Sunday, October 6, 13

56. DISTRIBUTED, I SAID
The more the merrier
Sunday, October 6, 13

57. System interconnects on servers
(depending on how you plan and set
them up) can still get more
performance over TCP/IP and
memory than a local server faced
with only its limited resources.
More servers = more memcached
WORDPRESS.COM
Yes, wordpress.com uses memcached. As do Twitter, Flickr,
Wikipedia, Craigslist, YouTube, and many others
Sunday, October 6, 13

58. $mc = new Memcache;
$mc->connect(‘10.0.1.20’, 11211);
$data = “cache this!”;
$mc->set(‘mydata’, $data, false, 100);
$result = $mc->get(‘mydata’);
MEMCACHED PHP
When installed Memcached will provide you a lot of PHP
functionality to have full control over your caching
Sunday, October 6, 13

59. BATCACHE
http://wordpress.org/plugins/batcache/
Place the advanced-cache.php
in your wp-content directory
“MEMCACHED PLUGIN”
Your mileage may vary
Sunday, October 6, 13

60. Single Malt Scotch
Hi Stefan!
Bourbon
Hi Mitch!
Tequila
Hi Kelly!
Beer
Hi Andrei!
LIFE IN THE SLOW LANE
If all this server and site performance is getting to you! :-)
Sunday, October 6, 13

61. http://eastbaywp.com/
http://www.stefandidak.com
DOWNLOAD THE SLIDES
Because this MAY have gone WAY too FAST for you!
Sunday, October 6, 13

62. Digital Ocean
https://www.digitalocean.com/
Redis
http://redis.io/
Linode
https://www.linode.com/
Memcached
http://memcached.org/
Rackspace
http://www.rackspace.com/
WordPress Batcache
http://wordpress.org/plugins/batcache/
Amazon VPC
http://aws.amazon.com/vpc/
WordPress APC Object Backend
http://wordpress.org/plugins/apc/
APC
http://php.net/manual/en/book.apc.php
XCache
http://xcache.lighttpd.net/
And finally, a “real developer’s” home office
because everyone keeps asking... :-)
http://www.stefandidak.com/office/
http://www.flickr.com/photos/didak/sets/72157633152434208/
eAccelerator
http://eaccelerator.net/
http://www.flickr.com/photos/didak/sets/72157632343719954/
Zend OpCache/Optimizer/Platform
http://en.wikipedia.org/wiki/Zend_Technologies
http://www.flickr.com/photos/didak/sets/72157632244753177/
Nginx
http://nginx.org/
Varnish
https://www.varnish-cache.org/
THINGS MENTIONED
In case you want to go look stuff up for yourself
Sunday, October 6, 13

63. QUESTIONS
Because I’m sure there’ll be some!
Sunday, October 6, 13