Network Management

Hardware Sensor (Node) variables do not load in Alert Trigger Action output preview in NPM 2026.1

When configuring an alert that uses Hardware Sensor (Node) as the alert object, the Select Variable to Insert dialog in the Trigger Action section may hang or continue spinning when users try to preview Hardware Sensor (Node) variables. In affected environments, this can also cause elevated SWIS CPU utilization and delay or prevent the variable list from loading.

First published date

6/12/2026 6:35 PM

Last published date

6/12/2026 6:41 PM

Overview

In NPM 2026.1, the Select Variable to Insert dialog may continue loading and fail to display results when users try to preview Hardware Sensor (Node) variables while configuring an alert action.

This issue can occur during the following workflow:

  1. Create or edit an alert that uses Hardware Sensor (Node) as the alert object.
  2. In the Trigger Action section, open Select Variable to Insert.
  3. Select Hardware Sensor (Node) variables for preview.

When the issue occurs, the variable preview may not load as expected. In some environments, this behavior may also increase SWIS CPU usage while the preview is being processed.

This can affect users who need to insert Hardware Sensor (Node) variables into alert action output and may delay alert configuration.

Product section

Network Performance Monitor

Cause

This behavior appears to be caused by the variable output preview attempting to traverse Hardware Sensor (Node) subentity data in a way that can significantly increase backend processing load. In larger Hardware Health environments, this can contribute to elevated SWIS CPU utilization and prevent the variable preview from loading successfully.

Resolution

Use Advanced Configuration settings in the SolarWinds Platform Web Console to limit how deep the system searches for subentities by adjusting MaxSearchDepthOfSubentitiesToPreview.

As a workaround, you can:

  • Set MaxSearchDepthOfSubentitiesToPreview = 0.

  • After this change, the Hardware Sensor (Node) variables loaded successfully in the alert Trigger Action preview.