Optimizing LAMPhp Applications

Transcript

1. Optimizing LAMPhp Applications RootConf, 26th May 2012 Piyush Goel Capillary

   Technologies [email protected]

2. Optimization “Premature Optimization is root of all Evil” - Donald

   Knuth Direction and Goal Oriented 26/05/2012 RootConf Takes Effort and Time No Silver Bullets, only guidelines and practices

3. Web Applications are like Onions !! 26/05/2012 RootConf

4. Web Applications are like Onions !! 26/05/2012 RootConf Layered Architecture

   Rocks !!

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6. Apache Apache 1.3 Pre-forked Model 1 process per request Robust:

   One crashed process dosen’t affect the others Not as fast as some other possible designs - Really ?? 26/05/2012 RootConf Apache 2.0 Multi-Processing Modules mpm_prefork mpm_worker

7. Tuning Apache • MaxClients • StartServers • Avoid thundering effect

   • MaxRequestsPerChild • Profiling first • AllowOverride 26/05/2012 RootConf • AllowOverride • HostnameLookups • TCP Buffering • Compression : mod_deflate/mod_gzip • May cause spike in CPU

8. Tuning Apache Contd • KeepAlive • N objects per page

   • t1 seconds for TCP connection • t2 seconds per object • K seconds timeout • Non-KeepAlive : N * (t1 + t2) 26/05/2012 RootConf • Non-KeepAlive : N * (t1 + t2) • KeepAlive : N * (t2) + t1 + K • For KeepAlive to perform better K < t1 * ( N -1 ) Ref: http://www.slideshare.net/techdude/building-scalable-php-applications

9. Tuning Apache Contd… Offload Static Files Apache + PHP not

   really good at static files Use Nginx or Lighttpd ( or anything else ) 26/05/2012 RootConf

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11. PHP Opcode Caching eAccelerator APC Zend_Cache Minimize Includes 1 include:

    1 stat and realpath system call 26/05/2012 RootConf 1 include: 1 stat and realpath system call Relative paths : too many stat system calls Minimal include_path Reduce logging : prevents disk writes error_reporting = E_COMPILE_ERROR|E_ERROR|E_CORE_ERROR

12. PHP Optimization contd… Output Buffering ob_start / ob_flush 26/05/2012 RootConf

    Compression ZLIB module ob_gzhandler

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14. MySQL under the hood 26/05/2012 RootConf

15. MySQL Tuning Hardware Config: Typical workloads are Memory/IO Bound Size

    of working data set Storage Engine: MyISAM vs InnoDB InnoDB works well in most cases, unless you need full text search 26/05/2012 RootConf InnoDB works well in most cases, unless you need full text search Cache static data: Memcached Swap Space: Actually made us

16. MySQL Tuning Contd… key_buffer_size innodb_buffer_pool_size innodb_log_file_size innodb_log_buffer_size innodb_flush_log_at_trx_commit thread_cache query_cache_size

    26/05/2012 RootConf query_cache_size Refer: 1) http://dev.mysql.com 2) http://www.mysqlperformanceblog.com/2006/09/29/what-to- tune-in-mysql-server-after-installation/

17. MySQL Tuning contd… Slow Query Logs: 1) Most important 2)

    Regular Monitoring 3) log_queries_not_using_indexes Analyze Tables periodically 26/05/2012 RootConf Optimize Table Abrupt query behaviors Avoid big deletes Use soft deletes Explain & Percona’s query visualizer

18. 26/05/2012 RootConf Tools and Practices

19. Tools and Practices Profiling: Profile regularly XDebug / Advanced PHP

    Debugger ( APD ) KCachegrind / Webgrind Instrument Code with Timers Load Testing / Benchmarking Apache Bench ( ab ) 26/05/2012 RootConf Apache Bench ( ab ) httperf JMeter ( personal favorite ) Strong Monitoring and Alerting Store exhaustively, Alert Judiciously Ganglia, Cacti Nagios etc

20. Tools & Practices 1) vmstat : Extremely useful for finding

    bottlenecks 2) iostat : Disk activity, useful for db systems 3) pmap : Process memory dump 4) strace: Analyzing system calls 5) sar : System activity reporter, good for postanalysis 26/05/2012 RootConf 5) sar : System activity reporter, good for postanalysis 6) netstat : Complete network dump 7) htop : Prefer over top 8) cut / tr : Analyzing Apache Access Logs

21. What It shouldn’t be !! 26/05/2012 RootConf SysAdmins vs Developers

22. Personal Rant/Advice 26/05/2012 RootConf Understand what’s happening under the hood

23. THANKS ! 26/05/2012 RootConf Capillary is looking for awesome DevAdmins!

    [email protected] [email protected]