如何进行PHP程序的堆栈转储

Question

A large third-party PHP application is taking a very long time (multiple seconds) to process a certain POST request. I need to find out what is taking so long.

In the Java land, taking a few thread dumps would often (not always) tell you where the program is stuck. Can I do something similar in PHP?

The debug_backtrace() function would not help in this situation, because I so not have a specific place in the PHP code where I would put debug_backtrace() call. Instead, I want PHP code to start executing, then dump a stack trace approximately 2 seconds into execution.

Answer 1

I would recommend you take a look at xdebug and doing proper profiling: http://www.xdebug.org/docs/profiler

You'll be able to generate a dump of all method calls in your application, which includes execution time. You can then load and analyse them with KCacheGrind/WinCacheGrind.