Kevin Schroeder has a new post to his site talking about real-time Magento logging and a library he's worked up to make it possible.

Ever since the Zend Developer Cloud started up it stirred in me some really interesting possibilities of what could be done. Sadly they never happened, but the ideas remained. If that doesn’t inspire you it’s because I’m not describing what I have in my head. I don’t have the time to do that. But this blog post is one part of it. One of the things that is part of what I envision is a realtime logger that shows what is happening, as it is happening. [Zend Server ZRay is] a cool feature but doesn’t quite go as far as I have in mind.

With that in mind I spent some time last week working on a very small piece of this vision for Magento. I wrote it really, really quickly and so don’t laugh when you look at the code and see obvious errors.

The library makes use of Magento extension and a command line program that uses a combo of Redis and PubSub for messaging back to the waiting logger. It hooks into all Magento events and allows for writing to the log from just about anywhere. It also includes a SQL profiler that will evaluate requests either in real-time or at the end of the request. He provides some additional details about the "watcher" command line tool and explanations for each of its options.