In the cloud world (which we've entered recently), most of the new applications are running in virtualized environments that are sold as services themselves (IAAS, PAAS).
This implies that a lot of responsibilities (infrastructure, network, OS, filesystem, and so on) are now out of our hands, which is good. But when we need to understand why our application has crashed or why it is particularly slow, we should be able to get our hands back on some of the responsibilities. For instance, our application might be slower at some point because the host network is overloaded or because the file system is being archived and is reducing the IO's performance.
Those facts have increased the need for monitoring, and this need has been tackled by great teams, building great products; New Relic (http://newrelic.com/) is one of them and probably the most famous one as well.
Actually, the Typesafe team is part of those smart teams, and so it has recently created a brand-new...