Caching has been a 'hot' topic for a few years. But caching takes more than merely taking data and putting it in a cache : the right caching techniques can improve performance and reduce load significantly. But we'll also look at some major pitfalls, showing that caching the wrong way can bring down your site. If you're looking for a clear explanation about various caching techniques and tools like Memcached, Nginx and Varnish, as well as ways to deploy them in an efficient way, this talk is for you.
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1. Caching and tuning funfor high scalability Wim Godden Cu.be
Solutions
2. Who am I ?Wim Godden (@wimgtr)Owner of Cu.be Solutions
(http://cu.be)Open Source developer since 1997Developer of
OpenXZend Certified EngineerZend Framework Certified EngineerMySQL
Certified Developer 3. Who are you ?Developers ?System/network
engineers ?Managers ?Caching experience ? 4. Goals of this
tutorialEverything about caching and tuningA few techniques How-to
How-NOT-to Increase reliability, performance and scalability5
visitors/day 5 million visitors/day(Dont expect miracle cure !) 5.
LAMP 6. Architecture 7. Test page3 DB-queries select firstname,
lastname, email from user where user_id = 5; select title,
createddate, body from article order by createddate desc limit 5;
select title, createddate, body from article order by score desc
limit 5;Page just outputs result 8. Our base benchmarkApachebench =
useful enoughResult ?Single webserverProxyStatic PHP Static
PHPApache + PHP3900 17.56700 17.5Limit : Limit :CPU, network
databaseor disk 9. Caching 10. What is caching ?CACHE 11. What is
caching ? x = 5, y = 2 Same resultn = 50 CACHE select * from
articlejoin user Doesnt changeon article.user_id = user.idall the
time order by created desc limit 10 12. Theory of cachingDBle t ab
fro m ul t res ata ned e ct d retursel ta = $da if ($data == false)
Page GET /pageset( key, $$dafals data)ta = eget( key)Cache 13.
Theory of cachingDBHITCache 14. Caching techniques#1 : Store entire
pages #2 : Store part of a page (block) #3 : Store data retrieval
(SQL ?) #4 : Store complex processing result #? : Your call !When
you have data, think :Creating time ?Modification frequency
?Retrieval frequency ? 15. How to find cacheable dataNew projects :
start from cache everythingExisting projects : Look at MySQL slow
query log Make a complete query log (dont forget to turn it off !)
Check page loading times 16. Caching storage - DiskData with few
updates : goodCaching SQL queries : preferably notDONT use NFS or
other network file systems especially for sessions locking issues !
high latency 17. Caching storage - Disk / ramdiskLocal5 Webservers
5 local cachesHow will you keep them synchronized ? Dont say NFS or
rsync ! 18. Caching storage - Memcache(d)Facebook, Twitter,
YouTube, need we say more ?Distributed memory caching
systemMultiple machines 1 big memory-based hash-tableKey-value
storage systemKeys - max. 250bytesValues - max. 1Mbyte 19. Caching
storage - Memcache(d)Facebook, Twitter, YouTube, need we say more
?Distributed memory caching systemKey-value storage system Keys -
max. 250bytes Values - max. 1MbyteExtremely fast... non-blocking,
UDP (!) 20. Memcache - where to install 21. Memcache - where to
install 22. Memcache - installation & running itInstallation
Distribution package PECL Windows : binariesRunning No config-files
memcached -d -m -l -p ex. : memcached -d -m 2048 -l 172.16.1.91 -p
11211 23. Caching storage - Memcache - some notesNot fault-tolerant
Its a cache ! Lose session data Lose shopping cart data ... 24.
Caching storage - Memcache - some notesNot fault-tolerant Its a
cache ! Lose session data Lose shopping cart data Firewall your
Memcache port ! 25. Memcache in code
