Once the data is in Circonus, you can start graphing the information and putting it on dashboards. Circonus has a great collection of graphing widgets, but they range in complexity and capability. The basic gauge, for instance, wanted me to specify a minimum and maximum value, a task it should do on its own. Ideally, it should be easy to configure the meter to start flashing when a value moves out of a historical range.
The map widget, on the other hand, will plot out locations on a global map. But it's not just any view of the world. You can choose a map based on the old Mercator projection that has distorted our view of the world since grade school, or you can pick among seven other options, including the Gall-Peters, an "equal area" view that will save you from overestimating the amount of land in Greenland. If only my website had readers in Greenland.
Circonus pricing is tiered. The lowest level, called Copper, covers two servers for $50 per month. The price per server falls as you add servers, running up to $750 per month to watch 50 servers. Each package includes a set number of metrics.
Circonus will install its monitoring solution inside your data center for a negotiated price, an option that might be more attractive than a hosted service to large enterprises and governments.
Circonus maintains a collection of agents around the world that can be summoned to ping your site.
Librato: Simple metrics or resource control The Librato world comes in two parts. The first part, called Metrics, is an online database for whatever you measure. It's connected to graphing and alerting engines. The second, Silverline, offers the instrumentation tools that dig up the numbers you might want to watch on your server. You can use one without the other or use them both, but they're relatively independent tools that don't use each other. If you log into one, you won't automatically be logged into the second.
The Metrics system is a Web-based graphing package for any kind of data you want to collect. You gather together your information in a JSON package and POST it to the Metrics URL. The next thing you know, your graphs are changing as the new data arrives.
Metrics is a flexible system because most software has the ability to send off an HTTP message today. JSON-based logging is becoming common, even for C-level programming. It took me only a few seconds to start sending messages via the Curl command line. The biggest glitch seemed to be caused by the fact that I wasn't including decimal points in my integers.