PHP X-Ray

PHP X-Ray (/php/xray) shows where a site's PHP is actually spending its time.

It is built on what the server already records rather than on a profiler you have to install. Every PHP-FPM pool this panel writes has request_slowlog_timeout and pm.status_path set, so PHP-FPM has been dumping the call stack of every slow request to disk, and answering questions about its own workers, all along.

Two views, answering different questions:

• Live — what every worker is doing this second, and whether the pool has run out of them. That is the answer no stack trace can give.
• Slow — the requests that crossed the threshold and the exact function each one was inside, grouped so the same bottleneck hit many times reads as one problem rather than many.