AppNeta TraceView (by Optaros)

AppNeta TraceView (formerly Tracelytics) is an Application Performance Monitoring third-party tool providing analysis and profiling to help identify and troubleshoot performance problems within your application. It monitors the application at the PHP level, but also calls to memcached, redis, SolR and MySQL.

TraceView can monitor Magento sites without that extension but this adds the following capabilities :

• Adds "layers" for key Magento request stages (init, rewrite, pre/post dispatch, load and render layout) to pinpoint issues
• Partitions traffic based on logged in / anonymous customers
• Tag Zend controllers for grouping requests by controller/action
• Injects Real User Monitoring (RUM) tracking code for browser side performance tracking

For more information : https://github.com/Optaros/optaros-traceview