PHP性能问题诊断与排查
2012-06-06 15:10:49 来源：我爱运维网评论：0 点击：

最近PHP性能问题频发，share一下最近对php Perfromance tracing思路和方法便于大家诊断和故障排查:宏观层面的监测工具大家都比较熟悉主要...

最近PHP性能问题频发，share一下最近对php Perfromance tracing思路和方法便于大家诊断和故障排查:
宏观层面的监测工具大家都比较熟悉主要关注CPU和network IO，这次主要介绍一下微观层面Php profiling(Xhporf)工具的使用和数据诊断：

* 宏观层面
- CPU
- Top
- load average
- Vmstat
- R
- cs
- Memory
- IO
- Iostat
- Network
- Mpstat
* 微观层面
- Strace
- Strace system call
- Strace PHP master process statistics
- Php-fpm configuration
- pm = static
- pm.max_children = 500
- request_slowlog_timeout = 6
- request_terminate_timeout = 10
- pm.max_requests = 1500
由于PHP服务器负载可以量化，不建议使用dynamic模式，static模式可以减少频发进程创建和消耗开销。
- Slow request
- Slow URL
抓起响应慢的url进行profiling分析
- Profiling
- Xhporf
诊断思路：从宏观层面分析系统资源消耗，如CPU bound or IO bound 等，目前PHP均是CPU bound和network IO消耗。跟踪Slow log,发现影响时间消耗最长的URL，添加Xhpof去定位详细的资源消耗。

* Xhporf installation and configuration
* Installation
* $wgethttp://pecl.php.net/get/xhprof-0.9.2.tgz

$tar xvf xhprof-0.9.2.tgz

           $cd./xhprof-0.9.2/extension/

           $/usr/local/php5/bin/phpize

           $./configure --with-php-config=/usr/local/php5/bin/php-config

           $make

           $make install

           xhprof.so将被生成在/usr/local/php5/lib/php/extensions/no-debug-non-zts-20090626/

           cp xhprof.so to /usr/local/php5/lib/php/extensions

           mkdir –p /home/logs/php/xhprof_log

* Configuring
- 编辑/usr/local/php5/lib/php.ini

                   添加下面内容到php.ini

           [xhprof]

           extension=xhprof.so

           xhprof.output_dir="/home/logs/php/xhprof_log"

* copy xhprof_html and xhprof_lib to web_root folder
- 修改响应时间慢的页面来自于Slow request log
如：application/index.php

                        在index.php头部加入下面

                         if (mt_rand(1, 100) == 1) {

                               if (extension_loaded('xhprof')) {

                              include_once '/home/pplive/web/test/xhprof_lib/utils/xhprof_lib.php';

                                include_once '/home/pplive/web/test/xhprof_lib/utils/xhprof_runs.php';

                                xhprof_enable(XHPROF_FLAGS_CPU + XHPROF_FLAGS_MEMORY);

                                $xhprof_on = true;

                   在index.php尾部加入下面

                 if ($xhprof_on) {

                   if (extension_loaded('xhprof')) {

                   $profiler_namespace = 'prd';  // namespace for your application

                       $xhprof_data = xhprof_disable();

                    $xhprof_runs = new XHProfRuns_Default();

                     $run_id = $xhprof_runs->save_run($xhprof_data, $profiler_namespace);

* 数据分析和诊断

Xhprof生成log在/home/logs/php/xhprof_log/4fcee1683ed38.prd

URL：http://address/index.php?run=4fcee1683ed38&source=prd
- Overall SummaryPage显示页面调用统计和详细的方法call，使用EXcl WALL time 排序可以得到消耗时间最长的方法调用便于发现系统或者子系统调用统计