Documentation forServer & Application Monitor

Manage application monitor thresholds in SAM

Thresholds are markers that indicate certain levels were reached, which you can adjust and set to act as trigger points for many component monitors included in SAM application monitor templates and application monitors, and other features such as Application Dependencies.

For example, to monitor CPU usage, a Critical threshold set at 90% would be typical. After setting thresholds, you can configure alerts so SAM sends an email when a Critical status threshold is breached.

If thresholds are set too low, you'll receive frequent alerts. If set too high, problems can occur without your knowledge.

The SolarWinds Platform includes predefined, general thresholds for most statistics, but you can override these thresholds and customize them on a per-object basis. For example, global thresholds exist for Disk Usage and Response statistics for all monitored nodes, but can be updated for specific nodes.

The following statistics have global thresholds that apply to each node monitored in the SolarWinds Platform, by default:

  • Average CPU load
  • Disk Usage
  • Percent memory Used
  • Percent Packet Loss
  • Response Time

To customize thresholds, you can set a static value or let the SolarWinds Platform calculate baseline values.

  • Static threshold. A constant value set for your threshold. For example, the warning threshold for response time might be 500 ms, and the critical value might be 1000 ms. You should be familiar with the performance of that object to know what a reasonable value for a static threshold is.
  • Dynamic baseline threshold. Data is collected for a week, and then used to calculate mean and standard deviation. The warning and critical threshold values are defined as 2 and 3 standard deviations above the mean, respectively. For example, if the mean value for packet loss for a specific node is 0%, the warning threshold for packet loss would be 3% (+2 standard deviations) and the critical threshold would be 4% (+3 standard deviations). Dynamic baseline thresholds are the most accurate way to define thresholds, and can be recalculated on demand.

Baseline data, as well as Warning and Critical thresholds for application monitors, can also be gathered and calculated automatically, as described in Adjust threshold settings and apply baseline data in SAM. The option to enter thresholds manually remains available. In general, you should monitor applications for several weeks to collect enough data to use as a baseline, and then make an educated guess about how to set Warning and Critical thresholds for component monitors.

By default, I/O thresholds of Windows Service Monitors are not set.

This section includes the following topics:

Additional resources about thresholds include:

For an overview about SAM application monitor alerts, watch Alerting on an application.