Pinba is a statistics server for PHP using MySQL as a read-only
interface.

It accumulates and processes data sent over UDP by multiple PHP
processes and displays statistics in a nice human-readable form of
simple "reports", also providing a read-only interface to the raw
data to enable generation of more sophisticated reports.

With the Pinba extension, users can also measure particular parts
of the code using timers with arbitrary tags.

Pinba is not a debugging tool in the common sense, since you're not
supposed to do debugging on production servers, but its main goal
is to help developers to locate bottlenecks in realtime and direct
their attention to the code that really needs it.

WWW:    http://pinba.org/