Compound Expressions Improve Your IT Monitoring

While today’s monitoring solutions help IT teams view their IT infrastructures with little to no tweaking, using an IT monitoring solution that allows for complex expressions can be very useful in improving reliability.

So what’s a complex expression? A compound expression is a series of simple expressions joined by arithmetic operators.  It’s a way of combining a series of thresholds together that, when in violation all at the same time, could lead to a bigger problem. Once these compound expressions are created, teams can apply those expressions to historical data to see if when problems began or occurred. Or they can combine them with their IT monitoring solution’s alerting capabilities to inform IT teams when certain conditions are met.


  1. A server’s heat increase and that additional heat affected the CPU. That caused website response time to degrade. A compound expression could be useful here to monitor CPU, temperature and web server response times.  By combining an alert with this expression IT admins can be notified in advanced before the problem becomes too serious.Temperature > 80 degrees AND CPU Time Busy > 90% AND response time < 5 seconds
  2. An engineer or IT admin notices problems with a particular server, and wants to pinpoint the time of the day that the server is performing the worst to see if a particular event may be the cause. A compound expression monitoring CPU, memory and disk usage would help.CPU Time Busy > 90% AND Memory Usage > 75% AND Disk Busy > 75%

Using an IT monitoring and analysis solution such as Sightline EDM, this expression can be used to perform root cause analysis. Once the expression has been created and data has been collected, the data can be plotted over a time period to find any violations.  Correlation can then be used with root cause analysis to find related events (across different systems). If you’re already an EDM user, I’ve even written a short guide on Creating Compound Expression Alerts in Sightline EDM.

Compound expressions, even such as the simple math equations above drastically improve your IT monitoring solution. It’s up to you to be creative and make awesome expressions to monitor your IT environment and solve problems when or even before they happen.